Dissertations / Theses on the topic 'Phenolic acids – Physiological effect'

[Truncated abstract. Please see the pdf format for the complete text.] Interest in the role of peroxynitrite in the pathogenesis of atherosclerosis has increased due to many in vitro studies which have demonstrated its potent oxidising and nitrating capability and immunohistochemical staining studies which demonstrate nitration of tyrosine in vivo. It is frequently suggested that the production of nitric oxide and superoxide at sites of inflammation implicates peroxynitrite as the major damaging reactive nitrogen species in vivo. Evidence for a role for peroxynitrite is often demonstrated by measurement of 3-nitrotyrosine yet even this cannot distinguish peroxynitrite from other nitrating species. Clearly, however, if peroxynitrite is important in atherogenesis, then identification of mechanisms for its detoxification could provide a means of preventing such effects. Therefore, this Thesis has sought to determine whether phenolic compounds of dietary origin can be preferentially nitrated by reactive nitrogen species thereby protecting endogenous structures, such as low density lipoproteins, from atherogenic modifications. This Thesis focuses upon phenolic acids as they have received relatively less attention than other classes of phenolic compounds, such as flavonoids, yet they are quite abundant in socially important beverages such as red wine. In order to complete the required analyses, the development of methods to detect phenolic acids and their nitration products together with 3-nitrotyrosine, dityrosine and 5-nitro-γ-tocopherol was necessary. The initial in vitro experiments described herein sought to determine the products of reaction of peroxynitrite with phenolic acids of the 4-hydroxy and 3,4-dihydroxy type and then to examine whether these products could account for a protective effect upon tyrosine, lipids and endogenous anti-oxidants, if any was observed, when isolated LDL was treated with SIN-1, which releases peroxynitrite through the simultaneous generation of nitric oxide and superoxide. A concurrent minor focus was to examine the relationship between structure and activity of these phenolic acids under various regimes of oxidative insult. These experiments indicate that, at least in this in vitro model, oxidation is a dominant mechanism over nitration. Peroxynitrite was shown to nitrate coumaric acid in moderate yields but exclusive oxidation of caffeic acid appeared to occur. Although a potential role for γ-tocopherol as an anti-nitration agent was inferred, all types of chemical treatment of LDL in the presence of phenolic acids yielded oxidation as the primary end point. In fact, nitration of tyrosine was not detected and nitration of coumaric acid was at the limit of detection. Since nitration of tyrosine is generally regarded as important in many disease states, a more physiological nitrating mechanism involving artificially stimulated neutrophils was used. This system demonstrated that although physiologically relevant reactive nitrogen species can result in nitration of phenolic compounds, in a complex system including biological structures (LDL) and phenolic compounds, oxidation but not nitration of all species appears to occur. As a consequence of the results above, an examination of carotid plaque was undertaken to determine to what extent nitration occurred relative to oxidation in atherosclerotic tissue. These studies applied methods developed herein to detect 3-nitrotyrosine and dityrosine in complex biological matrices as markers of nitration and oxidation respectively. The data obtained demonstrated that nitration was a minor modification of protein (0.01%) compared to oxidation (0.3%) even in a highly diseased tissue such as carotid artery plaque. A secondary study examining plasma revealed that dityrosine, which has been implicated in irreversible albumin aggregation in chronic renal failure and more recently in heart disease, is elevated in chronic renal failure subjects compared to well matched controls. A separate examination of plasma from healthy subjects revealed that in both the fasting and post prandial state 3-nitrotyrosine could not be detected and, in fact, interfering species could be problematic in the GC-MS analysis of 3-nitrotyrosine. The lack of nitration of any substrate observed in vitro using reactive nitrogen species generated in the aqueous phase, the relative lack of nitration of tyrosine in plaque proteins and the lipophilicity of nitric oxide, the precursor of all reactive nitrogen species, suggested that nitration could be more closely associated with lipid structures. The known ability of γ-tocopherol to form 5-nitro-γ-tocopherol was used to probe this concept. The 5-nitro-γ-tocopherol content of lipid extracts obtained from carotid artery plaques was very high (30%). This indicated that nitration is predominantly a lipid phase phenomenon and that nitrating species are present in much greater abundance than oxidising species in vivo.

Our objective was to investigate the mode of interaction between selected food proteins and phenolic compounds. Bovine serum albumin (BSA), bovine beta-lactoglobulin, and soybean glycinin were used with the following phenolic compounds; 3,4,5-trihydroxybenzoic acid (gallic acid), 3,4-dihydroxy cinnamic acid (caffeic acid), p -hydroxycinnamic acid (courmaric acid), and 5,7-dihydroxy 4-methoxy isoflavone (biochanin A). The interaction was investigated using incubation temperatures of 35°, 45° and 55°C at pH 5, 7 and 9. Native and SDS-polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy were used to identify protein-phenol interactions. Certain phenolic compounds combined with BSA and prevented protein aggregation. In general, the thermal stability of the proteins increased as a result of interaction with phenolic compounds; the most pronounced effect was observed with beta-lactoglobulin in the presence of gallic acid at pH 7. The interaction of the phenols with the proteins resulted in changes in protein secondary structure. (Abstract shortened by UMI.)

[ES] La citricultura se enfrenta a escenarios ambientales cambiantes que provocan diferentes estreses bióticos y abióticos que pueden dificultar la producción o afectar a la calidad de la fruta. El patrón sobre el cual se injerta una variedad específica es una importante herramienta para mejorar su adaptabilidad a cada área de cultivo. En la presente Tesis se realiza el estudio del efecto del patrón sobre la calidad físico-química y nutricional de la fruta en variedades de gran interés comercial en la actualidad, mandarinas 'Clemenules' y 'Tango' y naranjas sanguinas 'Tarocco Rosso' y 'Moro'. En 'Clemenules' se llevó a cabo la evaluación de la calidad de la fruta de árboles injertados sobre ocho patrones en tres momentos de cosecha durante dos campañas. Los patrones Forner-Alcaide 13 y C-35 destacaron por adelantar el cambio de color, lo que es de gran interés comercial. Por otra parte, Forner-Alcaide V17 destacó por mantener niveles óptimos de acidez hasta el final de la campaña y presentar el mayor contenido en vitamina C, flavonoides, glucosa y fructosa. Carrizo Citrange también indujo altas concentraciones de sacarosa y vitamina C. 'Tango' es una mandarina de reciente introducción en el área mediterránea de gran interés por su periodo de recolección tardío. En esta Tesis se abordó el estudio de los cambios en la calidad fisicoquímica, nutricional y sensorial de la mandarina 'Tango' injertada sobre dos patrones (Carrizo Citrange y Forner-Alcaide 5) en las dos áreas principales de producción de Andalucía. Los resultados revelaron que la calidad de la fruta se vio influenciada por la localización de las parcelas, lo que se relacionó con la composición de la textura del suelo. En ambas localizaciones, Forner-Alcaide 5 indujo mayor contenido en acidez, sólidos solubles totales, sacarosa, vitamina C y ácido cítrico en la fruta. Las determinaciones físico-químicas, junto con la evaluación sensorial permitieron establecer el momento óptimo de recolección dependiendo de las diferentes condiciones estudiadas. También se ha incluido un estudio del comportamiento postcosecha de esta variedad, ya que no existían datos en nuestras condiciones de cultivo. La mandarina 'Tango' presentó síntomas externos de daños por frío a partir de los 20 días almacenada a 1°C y 5°C. Se realizó un estudio micro-estructural para caracterizar la alteración. Los frutos del patrón Forner-Alcaide 5 presentaron una menor incidencia de los daños por frío. El almacenamiento a 9°C no comprometió la calidad externa o interna. Dentro del grupo de naranjas, en los últimos años existe una creciente demanda por las naranjas sanguinas para su consumo en fresco. Para evaluar el efecto del patrón se tomaron las variedades 'Moro' y 'Tarocco Rosso' injertadas sobre ocho patrones. La calidad interna se vio afectada por el momento de cosecha, siendo más evidente en 'Moro'. En ambas variedades el patrón afectó a los parámetros de calidad durante la maduración. En 'Moro', se observó una reducción en el color del zumo debido a la degradación de los antocianos, siendo los patrones C-35, Macrophylla y Volkameriana los que mostraron un mayor descenso. Esta degradación se relacionó con los cambio de la temperatura durante el periodo de recolección. En 'Tarocco Rosso' no se evidenció ninguna degradación, lo que sugiere que esta variedad es menos sensible a los cambios de temperatura. En esta variedad Forner-Alcaide 5 y Forner-Alcaide 13 produjeron fruta con mayor contenido en antocianos y azúcares. Además se llevó a cabo el estudio de la aptitud a la frigoconservación de las variedades de sanguinas 'Tarocco Rosso' y 'Sanguinelli'. Mientras que la calidad interna no se vio afectada por el almacenamiento (1°C, 5°C y 9°C) durante 45 días, la fruta presentó síntomas de daños por frío a 1°C. 'Sanguinelli' presentó mayor incidencia que 'Tarocco Rosso'. Estas sanguinas se pueden almacenar entre 5 y 9°C
[CA] La citricultura s'enfronta constantment a escenaris ambientals canviants que provoquen diferents estressos biòtics i abiòtics. El patró sobre el qual s'empelta una varietat específica és una important eina per a millorar la seua adaptabilitat agronòmica en cada àrea de cultiu. En la present Tesi s'ha dut a terme l'estudi de l'efecte del patró sobre la qualitat físic-química i nutricional de la fruita en varietats de gran interés comercial, mandarines 'Clemenules' i 'Tango' i, taronges sanguines 'Tarocco Rosso' i 'Moro'. En 'Clemenules' es va dur a terme l'avaluació de la qualitat de la fruita d'arbres empeltats sobre huit patrons en tres moments de collita, en dues campanyes. Entre els patrons avaluats, Forner-Alcaide 13 i C-35 van destacar per avançar el canvi de color. D'altra banda Forner-Alcaide V17 va destacar per mantindre nivells òptims d'acidesa fins al final de la campanya i va presentar el major contingut en vitamina C, flavonoides, glucosa i fructosa. Carrizo Citrange també va induir altes concentracions de sacarosa i vitamina C en la fruita. 'Tango' és una mandarina de recent introducció en l'àrea mediterrània amb gran interés pel seu període de recol·lecció que comença quan finalitza el de les clementines. En la present Tesi es van estudiar els canvis en la qualitat físic-química, nutricional i sensorial de la mandarina Tango empeltada sobre dos patrons (Carrizo Citrange i Forner-Alcaide 5) durant el període de collita en les dues àrees principals de producció d'Andalusia. La qualitat de la fruita es va veure influenciada per la localització, la qual cosa es va relacionar amb la composició de la textura del sòl. En totes dues localitzacions, Forner-Alcaide 5 va ser el patró que va induir major contingut en acidesa, sòlids solubles totals, sacarosa, vitamina C i àcid cítric en la fruita. Les determinacions físic-químiques i l'avaluació sensorial van permetre establir el moment òptim de recol·lecció depenent de les diferents condicions estudiades. També s'ha inclòs un estudi del comportament postcollita d'aquesta varietat, ja que no existien dades en les nostres condicions de cultiu. La mandarina 'Tango' va presentar símptomes externs de danys per fred a partir dels 20 dies emmagatzemada a 1°C i 5°C. Es va realitzar un estudi micro-estructural per a caracteritzar l'alteració provocada per les baixes temperatures. Els fruits del patró Forner-Alcaide 5 van presentar una menor incidència dels danys per fred. L'emmagatzematge a 9°C no va comprometre la qualitat externa o interna d'aquesta varietat. Dins del grup de taronges, en els últims anys existeix una creixent demanda per les taronges sanguines pel seu consum en fresc. Per a avaluar l'efecte del patró sobre sanguines es van prendre dues varietats, 'Moro' i 'Tarocco Rosso' empeltades sobre huit patrons. La qualitat interna es va veure influenciada pel moment de collita, la qual cosa va ser més evident en la varietat 'Moro'. En totes dues varietats el patró va afectar els canvis en els paràmetres de qualitat estudiats. En 'Moro', es va observar una reducció en el color del suc degut a la degradació del antocians. Aquesta degradació es va relacionar amb el canvi de la temperatura experimentada durant el període de recol·lecció. 'Tarocco Rosso' és menys sensible als canvis de temperatura. En aquesta varietat els patrons Forner-Alcaide 5 i Forner-Alcaide 13 van produir la fruita amb major contingut en antocianos i sucres. A mes s'aporta l'estudi de l'aptitud a la frigoconservació en les sanguines 'Tarocco Rosso' i 'Sanguinelli'. Mentre que la qualitat interna no es va veure afectada per l'emmagatzematge a cap de les temperatures assajades (1°C, 5°C i 9°C) durant 45 dies, la fruita va presentar símptomes de danys per fred a 1°C. `Sanguinelli' va presentar major incidència que 'Tarocco Rosso'. La fruita es pot emmagatzemar entre 5°C i 9°C durant 30 dies en el cas de 'Sanguinelli' i fins a 45 en e
[EN] Citriculture faces changing environmental scenarios that cause biotic and abiotic stress. The rootstock onto which a specific variety is grafted is an important tool to help to improve its agronomic adaptability to each crop area. The present Thesis was carried out to study the effect of rootstock on physico-chemical and nutritional fruit quality in some varieties of commercial interest today: 'Clemenules' and 'Tango' mandarins, and 'Tarocco Rosso' and 'Moro' blood oranges. In 'Clemenules', the fruit of the trees grafted into eight rootstocks at three harvest times was evaluated by performing studies during two seasons. Forner-Alcaide 13 and C-35 Citrange stood out for their earlier color change, which is very interesting for this variety, in which early harvesting is a relevant aspect from the commercial point of view. Forner-Alcaide V17 stood out for maintaining optimum acidity levels until the season ended and presented the highest contents in vitamin C, flavonoids, glucose and fructose. Carrizo Citrange brought about high concentrations of sucrose and vitamin C in fruit. 'Tango' is a mandarin variety that has been recently introduced into the Mediterranean Region. Its harvest time is very interesting because it starts when that of clementines ends. The present Thesis studies changes in the physico-chemical, nutritional and sensorial quality of 'Tango' fruit grafted onto two rootstocks (Carrizo Citrange and Forner-Alcaide 5) during the harvest period in the two main production areas in Andalusia. The results revealed that fruit quality during harvest was influenced by the location, which was particularly related to soil texture composition. In both areas, Forner-Alcaide 5 was the rootstock that induced higher acidity content, and more total soluble solids, sucrose, vitamin C and citric acid in fruit. The physico-chemical determinations, along with the sensorial evaluation, allowed the optimum harvest time to be established depending on the different studied conditions. This Thesis also includes a study about this variety's postharvest behavior as no data are available for our crop conditions. The 'Tango' mandarin presented outer chilling injury symptoms after being stored for 20 days at 1°C and 5°C. A microstructural study was done to characterize the alteration caused by low temperatures. The Forner-Alcaide 5 rootstock fruit showed a lower chilling injury incidence. Storage at 9°C did not compromise quality fruit. Among oranges, demand for blood oranges to be eaten fresh has grown in recent years, basically due to their high content in anthocyanins and their positive effect for human health. To assess the effect that rootstock had on blood oranges, two varieties were taken, 'Moro' and 'Tarocco Rosso', grafted onto eight rootstocks. Internal quality was strongly influenced by harvest time, which was more evident for 'Moro'. In both varieties, rootstock affected changes in the quality parameter studied. In 'Moro', juice color faded as anthocyanins degraded, and rootstocks C-35 Citrange, Macrophylla and Volkameriana showed the most marked reduction. Such anthocyanin degradation was related to the change in temperature that took place during the harvest period. In 'Tarocco Rosso', anthocyanins did not undergo degradation, which suggests that this variety is less sensitive to changes in temperature. In this variety, rootstocks Forner-Alcaide 5 and Forner-Alcaide 13 gave fruit with a higher content of anthocyanins and sugars. This Thesis also includes a study of the suitability of cold storage of two blood orange varieties: 'Tarocco Rosso' and 'Sanguinelli'. Although storage at any tested temperature (1°C, 5°C and 9°C) did not affect internal quality for 45 days, fruit displayed chilling injury symptoms at 1°C, with a higher incidence for 'Sanguinelli' than for 'Tarocco Rosso'. Fruit can be stored between 5°C and 9°C for 30 days for 'Sanguinelli' and for up to 45 days with 'Tarocco Rosso'.
This study has been supported by Instituto Valenciano de Investigaciones Agrarias and co-financed by FEDER and European Social Fund. The authors thank Anecoop S. Coop. and Frutaria Agricultura, S.L for supplying the fruit herein used and its technical support.
Morales Alfaro, J. (2021). Effect of Rootstock on the Fruit Quality of Mandarins "Clemenules" and "Tango", and Blood Oranges "Tarocco Rosso" and "Moro" [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165858
TESIS

Methylglyoxal (MGO) is a reactive carbonyl species found in Manuka honey reported to cause advanced glycation end products (AGE) formation. AGE’s increase the risk for hyperglycaemia resulting in neuropathy, arteriosclerosis, retinopathy and Alzheimer’s disease. Phenolic acids such as pyrogallol (PY) are known to trap MGO, lessening the harmful effects of MGO as an AGE precursor. However, MGO is also a very effective antibacterial agent therefore; its trapping could have negative side effects. Manuka honey contains both phenolic acids such as gallic acid (GA), caffeic acid (CA) as well as MGO and it is unknown whether trapping of MGO by phenolic acids reduces the antioxidant activity of phenolic acids or the antibacterial activity of MGO. Phenolic acids PY, GA and CA were combined with MGO in a 1:1 and 1:2 ratio. The trapping of MGO with polyphenolic acids was determined with Liquid chromatography-mass spectrometry (LCMS). Total polyphenolic acids (TPC) was determined with the TPC assay. Antioxidant activity was determined with 2,2-diphenyl-2-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC) and Oxygen Radical Absorbance Capacity (ORAC) assays. The effect on cell number and viability was determined with crystal violet and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays on Caco-2 and SC-1 cells. Cellular antioxidant activity was determined with Dichlorodihydrofluorescein diacetate assay. Lastly, antibacterial activity was determined with the turbidity assay on Gram positive B. subtilis and Gram negative E. coli and the ultrastructural morphology of B. subtilis was further investigated with scanning electron microscopy. PY was the only phenolic acid used with trapping ability, forming mono- and di- adducts with MGO reported with the LCMS results, resulting in a decrease in TPC and antioxidant activity measured with the DPPH assay. GA did not show any alteration when combined with MGO at 1:1 and 1:2 ratio in all antioxidant content and activity assays. The antioxidant content of CA in combination with MGO was decreased, although its antioxidant activity (DPPH) was increased at 1:2 ratio. The antioxidant activity measured with the ORAC assay was increased with PY and CA combined with MGO. TEAC assay did not show any changes when phenolic acids were combined with MGO a 1:1 and 1:2 ratio. The cytotoxicity of phenolic acids combined with MGO did not cause a change in cell number or viability of SC-1 and Caco-2 cells. MGO and phenolic acids alone and in combination did no cause oxidative damage (without 2,2'-Azobis(2- amidinopropane) dihydrochloride (AAPH). All phenolic acids in combination with MGO retained the ability to reduce AAPH induced oxidative damage. The polyphenolic acids showed minor inhibition of the growth of B. subtilis and E. coli. PY only reduced the antibacterial activity of MGO at a 1:1 combination of B. subtilis. GA and CA did not alter the antibacterial activity of MGO when combined at 1:1 or 1:2 ratio. This study showed that phenolic acids with the ability to trap MGO can be altered by the mono- and di-MGO adduct formation, altering its antioxidant activity and can further alter the antibacterial activity of MGO.
Dissertation (MSc)--University of Pretoria, 2017.
Anatomy
MSc
Unrestricted

Thirteen Ball State University, male basketball players participated in this study to examine the effects of an amino acid supplement, Rebuild IITM and glutamine, on strength and vertical jump performance. Rebuild IITM contains high levels of BCAA and glutamine.The thirteen subjects were divided into two groups, Rebuild IIT"'' (n=7) and placebo (n=6). Both groups participated in a ten week strength and conditioning training program. Subjects were pre and post-tested on the hang clean, bench press, squat, and the vertical jump. Changes in percent body fat were also compared. Pre and post measures were analyzed using a 2x2 ANOVA variance with a significant level set at p<0.05. Both groups showed significant increases between pre and post-test measurements in all of the variables measured, but could not be significantly proven to be due to treatment effect. It was concluded that with a controlled strength and conditioning program, basketball players would increase strength and vertical jump performance and decrease percent body fat. Yet in order to determine whether an amino acid supplement may further increase these measurements, a dietary recall must be obtained.
School of Physical Education

Computer-mediated communication [CMC] is beginning to be used more frequently in traditional classrooms. A group of physical chemistry professors have developed Physical Chemistry On-Line [PCOL] modules designed to augment in-class instruction and engage students at geographically dispersed institutions in activities to help them learn physical chemistry concepts. These modules use context-rich scenarios with a guided-inquiry approach, and the WWW and e-mail for information distribution and communication. This allows for intra- and inter-institutional collaboration between module participants. Three modules implemented during the Fall 2000 term are evaluated in this study. In order to assess the effectiveness of PCOL, each student completed a pre-module and post-module survey, pre-module and post-module content questions, and participated in an online discussion group. The primary focus of this analysis was to determine the student's: 1) perception of on-line activities, 2) perception of on-line interactions, and 3) use of computers.
School of Physical Education

Fourteen Ball State University softball players participated in this study to examine the effects of an amino acid supplement, Rebuild II TM, on strength and performance. Rebuild II TM contains high levels of BCAAs and glutamine. Two groups strength trained for ten weeks with the treatment group consuming Rebuild II TM, and the control group consuming a placebo. Subjects were pre and post-tested on the bench press, squat and machine shoulder press for strength, and performed a 90-foot sprint and a vertical jump for performance measures. LBW was calculated from the subjects body weight and percent fat. Pre and post measures were analyzed using a two way Anova variance with repeated measures test with a significant level set at p< 0.05. Both groups showed significant increases in strength and vertical jump performance, but only the Rebuild II TM group had a significant increase in LBW and decrease in percent fat. It was concluded that with a controlled weight training program, softball players will increase strength and vertical jump performance, and by adding an amino acid supplement to an athletes diet, there may be larger increases in LBW and decreases in percent fat while strength training.
School of Physical Education

Cyclopropene fatty acids (CPFA) found in cottonseed oil (CT) have been shown to reduce production of progesterone, a precursor of estrogen. Estrogenic hormones have been implicated in enhancing growth of mammary tumors. In this study, the effect of dietary cottonseed oil on estrogen production by mature female mice was determined by measuring urinary estrogen using High Performance Liquid Chromatography.At four months of age, five groups of three Strain A/ST female mice were placed on 20% fat diets containing 0, 2.5, 5.0, 10, and 20% cottonseed oil. The remainder of the fat in the experimental diets was corn oil sufficient to provide the balance of the 20% fat content in conjunction with other nutrients of equal percentages in all diets. At five day intervals mice were housed in metabolic cages and twenty-four hour urine samples were collected. Urine was purified on C18 columns and eluted with 1% phosphoric acid: acetonitrile: methanol: (54:35:11). Estrogen was quantified by High Performance Liquid Chromatography using a 250 X 5mm C18 column, hydrocortisone as an internal standard, and variable wavelength recorder set at 242 nm. The level of urinary estrogens after day 35 of the study was lower in all diets containing cottonseed oil. This is in agreement with several authors who have reported instances of physiological abnormalities in mammals which were fed increasing but low levels of dietary cyclopropenes. Since elevated estrogen levels have been identified as a risk for breast cancer, this study examines the relationship between dietary cyclopropenes and estrogen hormone production in strain A/St mice.
Department of Biology

Prostaglandin E2 (PGE2), a byproduct of arachidonic acid metabolism, has been suspected to be involved in tumor promotion. It has been suggested that diet may modulate PGE2 level in organisms thus affecting the implantation and growth of the tumor tissue. PGE2 content was investigated in mice fed ad libitum four types of fatty acid diets: saturated fatty acid diets: a stearic acid and a palmitic acid, and polyunsaturated fatty acid diets: a low fat (safflower 1%) and a high fat diet (safflower 15%). Tumor cells were implanted subcutaneously in mice and harvested when tumors reached .05- 4g. The extracted PGE2 were derivatized and quantified by High Performance Liquid Chromatography (HPLC). The results showed that there is a negative correlation between the level of PGE2 and the size of the tumors. PGE2 level declined as the tumor grew. This suggests that during the early stage of growth the tumor requires higher level of PGE2 to boost its growth. As the tumor becomes more adapted to its environment, it no longer depends on PGE2 to survive. Diet was also seen to be important in tumor suppression. Saturated fatty acid diet (SA-1) showed a suppressive effect on tumor growth. A visual comparison showed that polyunsaturated high fat diet produced more PGE2 than saturated fatty acid. This high level of PGE2 correlate with the highest tumor weights obtained in the Polyunsaturated high fat diet group.
Department of Biology

Dietary fatty acids are considered promoters of murine and human mammary tumors. The mechanism responsible is not known. Mammary adenocarcinomas in mice originate from preneoplastic cells (hyperplastic alveolar nodules (HAN)) which are derived from normal mammary epithelial cells. Diets rich in linoleic acid (18:2) have been associated with increased incidence of HAN and promotion of tumor growth. Diets rich in stearic acid (18:0) have been associated with decreased incidence of HAN and increased latency period for mammary tumor formation in mice.The effects of dietary 18:0 and 18:2 stages of murine mammary tumorigenesis were examined. The purpose of this study was to determine the effects of these dietary fatty acids on HAN production, mammary gland development, and fatty acid composition of mammary epithelial cells and adipocytes.Spontaneous mammary tumor producing strain A/ST mice were fed a high fat (15%) or low fat (5%) diet. High fat stock (ST) diet containing 1.5% 18:2 or a low fat corn oil (CO) diet containing 3% 18:2 were fed. Animals were sacrificed at 6 or 10 months of age. HAN, ductile and alveolar development were histologically determined in the left inguinal mammary gland. The contralateral gland was on the early diets rich in 18:2 (SF) or 18:0 (SA) were fed. A low*fat enzymatically dissociated and fatty acid compositions of adipocyte and epithelial cells were determined by GLC. Fatty acid profiles were examined for correlation to histologic findings.SA-fed mice had fewer HAN and less well developed mammary alveoli than the other dietary groups which exhibited moderate (ST) or high (CO, SF) HAN incidence. SF-fed mice had the earliest onset of any dietary group. CO-fed mice had later onset of HAN as compared to SF-fed mice but the HAN incidence was similarly high in both groups at 10 months of age.SA-fed mice were protected from development of expected numbers of HAN as compared to ST-fed mice. The reduction in HAN risk in this group was associated with reduced mammary alveolar development. Groups with high risk of HAN (SF and CO) exhibited increased amounts of 18:2 in their mammary epithelial cells and adipocytes.
Department of Biology

We examined the effect of a functional oil (FctO), with potential weight-controlling and blood lipid-lowering attributes, vs beef tallow as control (C), on the cardiovascular risk profile of overweight women. The FctO comprised energy expenditure-enhancing medium chain triacylglycerols, cholesterol-lowering phytosterols and triacylglycerol-suppressing n-3 fatty acids. In a randomized, single-blind, crossover design, inpatient trial, 17 women consumed each oil as part of a controlled, supervised, energy-adjusted diet for 27 days. Body weight decreased similarly during both dietary periods. Plasma total and LDL cholesterol levels decreased by 4.8% and 10.4% following FctO, and were lower by 9.0% and 16.4% respectively, after FctO vs C. HDL cholesterol and circulating triacylglycerol levels were unaffected by treatment, though HDL:LDL and HDL:total cholesterol ratios increased by 19.5% and 9.4% on FctO. Plasma total homocysteine levels were higher on FctO vs C. Plasma glutathione increased with FctO supplementation.
We conclude that consumption of FctO improves the overall cardiovascular risk profile of overweight women.

Biochemical theories postulate that deficient serotonergic functioning may be etiologically related to affective illness and aggressive behavior. In Study I mood and aggressivity were measured in thirty-six normal male subjects before and after ingestion of a Tryptophan Depleted, Tryptophan Loaded or Balanced amino acid mixture. While no differences in aggressivity were found, the Tryptophan Depleted group scored significantly higher at posttest on the MAACL Depression Scale than the control groups and demonstrated selective attention for dysphoric themes. In Study II a Balanced or Tryptophan Depleted amino acid mixture was administered to eighty normal male subjects prior to placing them in either a positive or negative environment, with or without instructions concerning the potential amino acid effects. The tryptophan depleted group became significantly more depressed than the control group regardless of environmental condition or instructional set. These findings suggest that lowered tryptophan may result in a central serotonergic dysfunction which is causally related to depressive affect and possibly to the pathogenesis of clinical forms of depression.

Dietary fats have been proposed to alter the amount of glucose transporters in various tissues. This study examined how diets containing linoleic or palmitic fatty acids affected the amount of the major insulin-responsive glucose transporter protein, GLUT-4, in red vastus muscle of mice. At 8 weeks of age, 28 healthy female mice were separated into 3 dietary groups, one control group (5% corn oil fat) and two high fat (15% fat) groups. One of the high fat diets was a linoleic acid rich diet (76% linoleic polyunsaturated fat), while the other was a palmitic acid rich diet (95% palmitic saturated fat). The mice remained on their respective diets for 12-13 weeks until sacrifice. Red vastus muscle samples were removed and prepared for GLUT-4 protein analysis. Homogenized red vastus muscle samples were separated by SDSPAGE, transfered to membrane paper, and immunoblotted. scanning densitometry determined the relative quantity of GLUT-4 from each sample. TAP GLUT-4 protein in the group fed the linoleic acid rich diet was 9% higher than the group fed the low fat diet, and 37% higher than the group fed the palmitic acid rich diet. These data suggest that a prolonged high fat diet consisting of linoleic or palmitic fatty acids play a role in the regulation of GLUT-4 protein content.
School of Physical Education

In experiment 1, fourteen cows were blocked for milk yields and balanced for days in lactation. Treatments were: (1) Air conditioning (AC), five cows; (2) Evaporative cooling (EC), four cows; and (3) Conventional shade (S), five cows. Sequential samples were taken for 8 h at 12 min intervals starting at 2200 and then at hourly intervals for 13 h. Serum was assayed for insulin, thyroxine (T4), triiodothyronine (T3) and cortisol using a double-antibody radioimmunoassay procedure. Free fatty acids (FFA) were determined in serum by an enzymatic method. In experiment 2, ten cows were blocked for milk yields and days in lactation. Treatments were: (1) Evaporative cooling (EC), five cows; and (2) conventional shade (S), five cows. Blood was drawn at 60 and 90 d of lactation. Blood sampling, hormone and FFA assays were carried out as in experiment 1. Sequential samples were taken for 8 h at 12 min intervals starting at 2300 and then at hourly intervals from 1030 to 1830. In experiment 1, insulin was depressed (P <.05) treatment effects for T3 in either experiment. There were significant treatment differences (P <.05) in respiration rates and body temperatures in experiment 1. Shade were higher than AC or EC cows. These studies demonstrated that summer heat stress depressed insulin and increased FFA with variable effects on T4 and cortisol but no effect on T3.

This thesis consists of a brief description on cancer, carcinogenesis, the changes in the type and level of dietary fat available in our diets over time and association with the development of certain diseases. The main focus of this research was on omega 6 and omega 3 essential fatty acids (EFA) and their interaction with regards to carcinogenesis.

Lysophosphatidic acid (LPA) influences many physiological processes, such as brain and vascular development. It is associated with several diseases including ovarian cancer, breast cancer, prostate cancer, colorectal cancer, hepatocellular carcinoma, multiple myeloma atherosclerotic diseases, cardiovascular diseases, pulmonary inflammatory diseases and renal diseases. LPA plasma and serum levels have been reported to be important values in diagnosing ovarian cancer and other diseases. However, the extraction and quantification of LPA in plasma are very challenging because of the low physiological concentration and similar structures of LPA to other phospholipids. Many previous studies have not described the separation of LPA from other phospholipids, which may make analyses more challenging than necessary. We developed an SPE extraction method for plasma LPA that can extract LPA at high purity. We also developed an HPLC post-column fluorescence detection method that allows the efficient quantification of LPA. These methods were used in a clinical study for ovarian cancer diagnosis to help validate LPA as a biomarker of ovarian cancer. Moreover, molecular imprinted polymers (MIPs) were designed and synthesized as material for the improved extraction of LPA. Compared to the commercially available materials, the MIP developed shows enhanced selectivity for LPA. The extraction was overall relatively more efficient and less labor-intensive.

The specific objective of this study was to determine if Fgf-3 gene expression is mediated by dietary fatty acids and to confirm mouse mammary tumor virus infection. It is well known that dietary linoleic acid enhances growth and dietary stearic acid inhibits growth of mammary tumors. Tumor RNA was extracted from female strain A/St mice fed one of four diets. A radioactively labeled anti-sense RNA probe was generated, invitro, from isolated and purified pFgf-3c (int-2c clone contained in the vector pSP65). The Fgf-3c probe was hybridized to extracted tumor RNA using the ribonuclease protection assay.Electron microscopy confirmed MMTV infection by visualization of type A and B particles in tumor tissue. Expression of Fgf-3c, qualified by RNase protection assay, ranged from 0.02 to 5.89 (relative band density) in all of the diet groups. A positive association between Fgf-3c expression and weight was observed among the tumors of the SA-1 diet (R = 0.947). The SF, SF-1, and PA experimental diets, individually, did not appear to show strong correlation with respect to tumor size. Fgf-3 expression was less in small tumors (<275 mg) and enhanced in large tumors (>275 mg) (p<0.05).
Department of Biology

The purpose of this study was to analyze the effect of fatty acid chain length and quantity on the bioavailability of calcium. Thirteen healthy subjects were randomly assigned to a series of 5 test meals containing varying types and levels of fat and calciumconsumed over a three week time period. The test meals included 10 grams MCT oil (MCT 10), 20 grams MCT oil (MCT 20), 10 grams beef fat (BT 10), 20 grams beef fat (BT 20), and calcium only (Ca). Calcium absorption was assessed using timed urine collections following a specified calcium load. Three day food records were obtained to assess typical nutrient intakes of the subjects coming into and during the study. MCT oil provided better absorption of the calcium supplement than did the beef tallow. A difference was also noted in the absorption of calcium based on the amount of fat consumed. A higher intake of MCT oil (10 g vs. 20 g) appeared to favor the absorption of calcium. Urine calcium excretion was significantly greater (p < .009) during the MCT oil treatments (MCT 10, MCT 20) compared to the beef fat treatments (BT 10, BT 20), suggesting reduced calcium absorption during the beef fat treatments. There were no differences in mean calcium excretion based on quantity of fat consumed ( 10 g vs. 20 g), nor any interaction between type of fat and amount. Tests for detecting differences between individual treatments indicated a significance difference (p < .05) in calcium excretion between MCT 20 and BT 10 treatments. Urine calcium excretion was corrected for body size using urine calcium/creatinine ratio (Ca/Cr). There was a significant time effect between the 0 - 2, 2 - 4 hour time periods (p < .005) and the various treatments for Ca/Cr. Though not significant, mean Ca/Cr was highest for the calcium treatment (0.42), compared to the MCT oil treatments (36, z of MCT 10 & MCT 20), and beef fat treatments (28, x of BT 10 & BT 20). The beef fat treatments significantly decreased the absorption of calcium compared to the MCT oil treatments. It appears that beef fat, when compared to the calcium only treatment, decreased calcium absorption.
Department of Home Economics

Mestrado em Biotecnologia - Biotecnologia Alimentar
Wheat is one of the most important grain in human diet and it is the most grown cereal crop wordwide. Nowadays since global climatic changes have become more important to food production, we asked whether climatic conditions and genotype would influence the production of healthy compounds on old and new varieties of durum wheat. Resistant starch and phenolic acids were quantified by HPLC techniques to evaluate the environmental and genotypic effects and to characterize four durum wheat species grown in South Italy. Environment had a strong impact on the production of resistant starch and phenolic acids, while genotype had the greastest effect on the same compounds. The production of phenolic acids tended to increase by the effect of winter sowing season and the year 2014 during the grain filling period. Ferulic and sinapic acid were the most abundant in the four varieties. The two new Ethiopian lines were more efficient on the production of phenolic acids and resistant starch, while the old genotype Trinakria and its genetic modified pair showed to be slightly less productive. Wheat based products higher in phenolic acids and resistant starch might lead to a diet richer in bioactive substances that promote health.
O trigo é um dos cereais mais importantes na alimentação humana e um dos mais produzidos a nível mundial. No momento em que as alterações climáticas parecem ser cada vez mais importantes na produção de alimentos, foi questionado se as condições climáticas e o genótipo poderiam influenciar a produção de compostos benéficos para a saúde em variedades antigas e novas de trigo duro. O amido resistente e os ácidos fenólicos foram quantificados através de técnicas cromatográficas para avaliar os efeitos ambientais e genotípicos e para caracterizar quatro variedades de trigo duro cultivadas no sul de Itália. O ambiente influenciou a produção de amido resistente e de ácidos fenólicos, enquanto que o genótipo teve o maior impacto nestes. A produção de ácidos fenólicos tendeu a aumentar pelo efeito da estação invernal e do ano 2014 no período de enchimento dos grãos. Os ácidos ferúlico e sinápico foram os mais abundantes nestas variedades. As duas linhas genotípicas Etiopia novas foram as mais eficientes na produção de ácidos fenólicos e amido resistente, enquanto que o genótipo antigo Trinakria e o seu par geneticamente modificado mostraram ser ligeiramente menos produtivos. Pensa-se que os produtos alimentares à base de trigo com um conteúdo de amido resistente e ácidos fenólicos elevado conduzem a uma dieta mais rica em substâncias bioactivas que promovem a saúde humana.

Current feed formulations within the aquaculture industry have tended to rely on high dietary lipid thus offsetting relatively expensive protein as a source of energy. In this way, protein can be ‘spared’ for synthesis of new tissue and the high lipid content can also fulfil both fish and consumer essential fatty acid (EFA) requirements. However, the main disadvantage of feeding high lipid levels to farmed fish is a surplus of fat deposition in the flesh and other important tissues, which can detrimentally impact on quality characteristics central to the human consumer. However, based on previous work in other animal models, it is entirely feasible that supplementation of the diet with bioactive fatty acids such as conjugated linoleic acid (CLA) and tetradecylthioacetic acid (TTA) may mitigate the deleterious effects of feeding farmed fish high fat diets by reducing fat deposition in particular. The general objective of this research work was to test the hypothesis that CLA and/or TTA could augment growth, reduce fat deposition and enhance fatty acid composition via incorporation of these bioactive fatty acids, and increase n-3 highly unsaturated fatty acid (HUFA) levels in the flesh of commercially important fish species such as Atlantic salmon (Salmo salar), Atlantic cod (Gadus morhua L.) and rainbow trout (Oncorhynchus mykiss). This project also considered the influence of CLA and TTA on enzymes and transcription factors thought to be pivotal in lipid metabolism and fatty acid oxidation in particular. A subsidiary aim of this research work was to investigate the immunological impact of dietary CLA and TTA administration in these fish. The results of this project have revealed that the hypothesis was only partly proved. There was no effect in growth or biometry after either CLA or TTA supplementation in any of the fish species investigated. Additionally, there were few physiologically significant effects on fat levels on fish as a result of TTA or CLA administration. However, there were a number of effects on fatty acid metabolism including inhibition of steroyl coenzyme desaturase (SCD) in cod and trout in particular and also enhancement of hepatic n-3 HUFA levels in trout. Importantly, it was determined that both TTA and CLA could be incorporated into the flesh thus providing a vehicle through which these bioactive fatty acids can be delivered to the consumer. There were also a number of beneficial effects on activity and gene expression of a number of enzymes and transcription factors thought to be fundamental to the modulation of fatty acid oxidation in particular. However, the effects on gene transcription and biochemistry had little impact at the whole body level. This research work also showed that there were no detrimental effects on immune status after supplementation with dietary CLA or TTA. Conclusively, this thesis has contributed to the overall understanding of the influence of dietary CLA and TTA in farmed fish.

Previous nutritional physiology research using L-histidine and zinc in American lobster intestine (Homarus americanus) has suggested that these solutes can be co-transported as complexes (Histidine-Zinc-Histidine) across the intestine using a peptide transporter. Furthermore, transport of L-leucine was shown to be inhibited by high calcium concentrations. Dipeptide and bis-complex transport and the role of calcium were investigated in the perfused intestines of lobster and Atlantic white shrimp (Litopenaeus setiferus). Following trans-intestinal transport, serosal medium was analyzed for amino acid composition by gas chromatography. In lobster, the transport of glycylsarcosine (Gly-Sar) from mucosa to serosa was stimulated two-fold with luminal pH 8.5, compared to the pH 5.5 control. Mucosa to serosa and serosa to mucosa fluxes of Gly-Sar were measured; the dipeptide was transported intact in both directions, but the net flux was from mucosa to serosa. The use of 0.5mM calcium chloride stimulated Gly-Sar transport two-fold, compared to 25 mM. In shrimp, the addition of 50 µM zinc chloride increased the rate of L-histidine transport, while Gly-Sar inhibited histidine transport in the presence of zinc. The rate of histidine transport was significantly higher with 1mM calcium chloride than with 25mM. These results suggest that shrimp transport bis-complexes in a manner similar to lobster. High calcium concentration had an inhibitory effect on both amino acid and dipeptide transport. Proposed mechanisms accounting for the effects of metals and calcium on trans-intestinal transports of both amino acids and dipeptides by lobster and shrimp digestive tracts are discussed.

The scope of the present work was to investigate whether the protective role of the traditional Mediterranean diet (TMD), and virgin olive oil (VOO) rich in phenolic compounds (PC), towards cardiovascular disease can be mediated through gene expression changes. Two trials were performed to assess the in vivo nutrigenomic effects of TMD and VOO in healthy volunteers. The results point out: a) significant gene expression changes of those genes related with cardiovascular-risk processes after VOO ingestion; b) a down-regulation in the expression of atherosclerosis-related genes after a 3-month intervention with a TMD; and c) an olive oil PC health-protective nutrigenomic effect within the frame of the TMD. Changes in gene expression were concomitant with decreases in oxidative damage and systemic inflammation markers. Data from our studies provide further evidence to recommend both the TMD and the VOO as a useful tool for the prevention of atherosclerosis.
El objetivo de este estudio es investigar si el papel protector de la dieta Mediterránea tradicional (TMD) y del aceite de oliva virgen (VOO), rico en compuestos fenólicos (PC), puede ser mediado a través de cambios en la expresión génica. Se realizaron dos ensayos clínicos para evaluar los efectos nutrigenómicos de la TMD y del VOO, in vivo, en voluntarios sanos. Los resultados mostraron a) cambios en la expresión génica de genes relacionados con el riesgo cardiovascular tras la ingestión del aceite virgen de oliva, b) una infra-expresión en la expresión de genes relacionados con el proceso aterosclerótico tras una intervención con TMD de 3 meses y c) que los compuestos fenólicos del aceite de oliva ejercen un efecto nutrigenómico protector en el marco de la TMD. Los cambios en la expresión génica fueron coherentes.

I. DESCRIPTION DE PROJET DE RECHERCHE

Le canal sodium épithélial bloquable par l’amiloride (ENaC) est une protéine intégrale de la membrane apicale des épithéliums impliqués dans l’absorption du sodium. Deux fonctions majeures sont directement liées au fonctionnement d’ENaC. D’une part, la régulation de la balance sodée par le rein et donc de la pression artérielle et d’autre part, la clairance du fluide alvéolaire pulmonaire.

Le transport vectoriel de sel et d’eau à travers ces épithéliums à jonctions serrées repose sur un transport actif de sodium entraînant un flux osmotique d’eau. Ce transport de sodium s’effectue en deux étapes: l’entrée apicale, par diffusion, facilitée via ENaC, et la sortie basolatérale, active, par les pompes Na+/K+ ATPases.

Ces dernières années, un intérêt grandissant est porté sur les acides gras polyinsaturés à longues chaînes de type oméga 3 (PUFAs) et leurs implications dans divers processus physiologiques. Entre autres effets, les PUFAs modulent différents types de canaux ioniques (canaux Na+ dépendant du voltage, Ca++ L-type, K+).

Les études in vivo impliquant un effet à long terme des PUFAs décrivent des mécanismes inhibiteurs. Cependant, lors d’une étude précédente, axée sur la composition lipidique des membranes de cellules rénales en culture et l’influence de l’ajout d’acides gras saturés et insaturés sur le transport du sodium, nous avons constaté que les acides gras polyinsaturés à longues chaînes de type oméga 3 augmentaient la réabsorption du sodium. Ces résultats pourraient être intéressants, car les canaux sodiques de l’épithélium alvéolaire sont en contact direct avec le surfactant, dont la composition lipidique varie en fonction de l’apport alimentaire en PUFAs. Chez les prématurés humains, le syndrome de détresse respiratoire est une des causes les plus fréquentes de mortalité. Dans un certain nombre de cas, on peut restaurer une fonction pulmonaire satisfaisante par l’administration de surfactant.

Dans ce travail, nous avons opté pour une approche fondamentale des mécanismes de régulation du canal sodium épithélial par l’acide eicosapentanoïque (EPA, C 20:5, n-3). Des études électrophysiologiques, biochimiques et d’imagerie cellulaire ont été réalisées sur la lignée cellulaire A6 de rein d’amphibien, qui sert d’épithélium modèle pour l’étude d’ENaC depuis plus de 25 ans. Cette lignée exprime des canaux sodiques très sélectifs et possède des propriétés électrophysiologiques facilitant l’étude de leur régulation.

Ce travail nous a permis de mettre en évidence de nouveaux mécanismes fondamentaux dont la pertinence physiologique et /ou clinique ne pourra être établie qu’en transposant cette étude sur un modèle in vivo, comme nous le proposons dans les perspectives.

Dans le présent travail, nous avons étudié :

1.\
Doctorat en Sciences biomédicales et pharmaceutiques
info:eu-repo/semantics/nonPublished

Inflammation is the body's response to injury and is characterized by pain, swelling, redness, and heat. Eicosanoids are lipid mediators of inflammation. Leukotrienes (LT) are 20-carbon eicosanoids produced from arachidonic acid (AA), an n-6 fatty acid (FA), and eicosapentaenoic acid (EPA), an n-3 FA. LT produced from AA are proinflammatory (LTB₄) and those produced from EPA (LTB₅) are less inflammatory. Two experiments were conducted. The objective of the first experiment was to optimize the assay conditions for LT production by platelets from chickens, and neutrophils from horses and dogs. Optimal production of LT from equine and canine neutrophils and chicken platelets was characterized in terms of incubation time (2.5, 5, 10, 15 or 20 minutes), temperature (25 or 37°C), and calcium ionophore A23187 concentration (0.1, 1, 10 or 20 μM). In all species, incubation at 37°C resulted in optimal LTB₄ production compared to 25°C (p≤0.05). Production of LTB₄ was maximum when neutrophils were stimulated with 20 μM calcium ionophore A23187 in all species (p≤0.05). Incubation times greater than 2.5 minutes did not further increase LTB₄ production in chickens and horses; in dogs, incubation for 2.5 and 10 minutes resulted in the highest concentrations of LTB₄ (p≤0.05). These results indicate that platelets from chickens, and neutrophils from horses and dogs, are capable of producing LTB₄; optimum conditions for LTB₄ production are similar in all three species. In the second study, the effect of feeding diets that differed in n-6 and n-3 FA ratios to breeder hens was investigated with regard to changes in composition of immune tissue, alteration of delayed-type-hypersensitivity (DTH) response, and LT production by platelets. Chicks hatched to hens fed these diets were also studied with regard to fatty acid composition of immune tissues and LT production by platelets at various stages of growth (7, 14, 21 days). A total of 72 breeder hens were randomly divided into three groups (n=24) and fed diets supplemented with either 3.0% (by weight) sunflower oil (SF0; rich in n-6 FA; Diet I), a mixture of 1.5% SF0 and 1.5% fish oil (Diet II), or 3.0% fish oil (FO; rich in n-3 FA; Diet III). Production of LTB₄ and LTB₅ by platelets stimulated with calcium ionophore A23187 were assessed by RP-HPLC. The hens fed Diet I synthesized 43.9 ± 2.5 ng of LTB₄ per 5x10⁶ cells compared to 13.3 ± 0.9 ng of LTB₄ from hens fed Diet II (p≤0.05). However, no LTB₄ was produced by hens fed Diet III. Production of LTB₅ by platelets of hens fed Diet III was 36.7 ± 4.9 ng compared to 47.4 ± 5.7 ng of LTB₅ from hens fed Diet II. No LTB₅ was produced by hens fed Diet I. The DTH reaction was smaller at 48 hrs post injection of bovine serum albumin in hens fed the 3% FO Diet III (p≤0.05). Fatty acid composition spleen and platelets in hens reflected the fatty acid composition of diets consumed by them (p≤0.05). Hatched chicks from hens fed Diet I produced significantly less LTB₄ at 14 days (p≤0.05) compared to 7- and 21-day-old chicks, which were not different from each other. Chicks from hens fed Diet II produced more LTB₄ at 21 days (p≤0.05) compared chicks from hens fed Diet III produced more LTB₄ at 7 and 21 days (p≤0.05) compared to 14-day-old chicks. There were no significant differences in LTB₅ production from chicks hatched to hens fed Diet III at 7 and 14 days of growth. By 21 days of growth, chicks hatched to hens fed Diet III showed decreased production of LTB₅ compared to 7- and 14-day-old chicks. The spleen and bursa tissue fatty acid composition in chicks at 7 and 14 days of age were similar to the maternal diet fatty acid composition, however, there were no significant differences in platelet fatty acid composition between the groups at different stages of growth. These results indicate that the type of fat in diets fed to breeder hens may alter the inflammatory response in hatched chicks, which could lead to less mortality and increased production performance in poultry.
Graduation date: 2005

Lam, Cheuk Kai.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 148-173).
Abstracts in English and Chinese.
ACKNOWLEDGEMENTS --- p.i
ABSTRACT --- p.ii
LIST OF ABBREVIATIONS --- p.vi
TABLE OF CONTENTS --- p.x
Chapter CHAPTER 1 --- GENERAL INTRODUCTION
Chapter 1.1 --- Introduction to Cholesterol and Its Related Diseases --- p.1
Chapter 1.1.1 --- Chemistry of cholesterol --- p.1
Chapter 1.1.2 --- Physiological importance of cholesterol --- p.1
Chapter 1.1.3 --- Pathological effects of cholesterol --- p.3
Chapter 1.1.3.1 --- Mechanism of atherosclerosis --- p.3
Chapter 1.2 --- Cholesterol Homeostasis --- p.6
Chapter 1.2.1 --- Liver as the main organ for cholesterol metabolism --- p.6
Chapter 1.2.2 --- Regulatory sites of cholesterol metabolism --- p.6
Chapter 1.2.2.1 --- Regulation of cholesterol absorption by acyl coenzyme A: cholesterol acyltransferase (ACAT) --- p.6
Chapter 1.2.2.2 --- Sterol regulatory element-binding protein 2 (SREBP-2) as a transcription factor for 3 -hydroxy-3 -methylglutaryl coenzyme A reductase (HMGR) and low-density lipoprotein receptor (LDLR) --- p.10
Chapter 1.2.2.3 --- Roles ofLDLR --- p.11
Chapter 1.2.2.4 --- Rate limiting role of HMGR in cholesterol de novo synthesis --- p.14
Chapter 1.2.2.5 --- Roles of liver-X-receptor-a (LXR-a) in cholesterol catabolism --- p.16
Chapter 1.2.2.6 --- Roles of CYP7A1 in catabolism of cholesterol into bile acids --- p.19
Chapter 1.2.2.7 --- Roles of cholesterol ester transfer protein (CETP) in maintaining cholesterol distribution in blood --- p.22
Chapter CHAPTER 2 --- EFFECT OF OCTADECAENOIC ACIDS ON BLOOD CHOLESTEROL IN HAMSTERS
Chapter 2.1 --- Introduction --- p.25
Chapter 2.1.1 --- Effects of polyunsaturated fatty acids (PUFAs) on blood cholesterol --- p.25
Chapter 2.1.2 --- Differential effects of 18-C PUFAs on lowering blood cholesterol in vivo --- p.25
Chapter 2.1.3 --- "Structures, metabolism and conjugation of octadecaenoic acids (ODA)" --- p.26
Chapter 2.1.4 --- Objectives --- p.26
Chapter 2.2 --- Experiment 1 --- p.28
Chapter 2.2.1 --- Materials and methods --- p.28
Chapter 2.2.1.1 --- Experimental fatty acids --- p.28
Chapter 2.2.1.1.1 --- Isolation of LN from flaxseed --- p.28
Chapter 2.2.1.1.2 --- Isolation of CLN from tung seed --- p.28
Chapter 2.2.1.2 --- Animals --- p.29
Chapter 2.2.1.3 --- Diets --- p.30
Chapter 2.2.1.4 --- Plasma lipid measurements --- p.30
Chapter 2.2.1.5 --- Plasma CETP activity measurement --- p.30
Chapter 2.2.1.6 --- "Measurement of liver SREBP-2, LDLR, HMGR and CYP7A1 protein abundance by Western blotting" --- p.34
Chapter 2.2.1.7 --- "Measurement of hepatic SREBP-2, LDLR, HMGR, LXR, CYP7A1, CETP, SR-B1 and LCAT mRNA by real time PCR" --- p.35
Chapter 2.2.1.7.1 --- Extraction of mRNA --- p.35
Chapter 2.2.1.1.2 --- Complementary DNA synthesis --- p.36
Chapter 2.2.1.7.3 --- Real-time polymerase chain reaction (PCR) anaylsis --- p.36
Chapter 2.2.1.8 --- Determination of cholesterol in liver --- p.37
Chapter 2.2.1.9 --- Determination of fecal neutral and acidic sterols --- p.38
Chapter 2.2.1.9.1 --- Determination of fecal neutral sterols --- p.39
Chapter 2.2.1.9.2 --- Determination of fecal acidic sterols --- p.41
Chapter 2.2.1.10 --- Statistics --- p.43
Chapter 2.2.2 --- Results --- p.44
Chapter 2.2.2.1 --- Growth and food intake --- p.44
Chapter 2.2.2.2 --- Organ weights --- p.44
Chapter 2.2.2.3 --- "Effects of ODA on serum TC, TG and HDL-C" --- p.44
Chapter 2.2.2.4 --- Effect of ODA on liver cholesterol --- p.48
Chapter 2.2.2.5 --- Effect of ODA on fecal neutral sterol output --- p.48
Chapter 2.2.2.6 --- Effect of ODA on fecal acidic sterol output --- p.48
Chapter 2.2.2.7 --- Effect of ODA on cholesterol balance in hamsters --- p.52
Chapter 2.2.2.8 --- Effect of ODA on plasma CETP activity --- p.52
Chapter 2.2.2.9 --- Correlation between blood TC and liver cholesterol --- p.52
Chapter 2.2.2.10 --- Correlation between blood HDL-C and liver cholesterol --- p.52
Chapter 2.2.2.11 --- Correlation between blood nHDL/HDL ratio and liver cholesterol --- p.52
Chapter 2.2.2.12 --- Effect ofODA on liver SREBP-2 immunoreactive mass --- p.58
Chapter 2.2.2.13 --- Effect of ODA on liver LDLR immunoreactive mass --- p.58
Chapter 2.2.2.14 --- Effect of ODA on liver HMGR immunoreactive mass --- p.58
Chapter 2.2.2.15 --- Effect of ODA on liver LXR immunoreactive mass --- p.58
Chapter 2.2.2.16 --- Effect of ODA on liver CYP7A1 immunoreactive mass --- p.63
Chapter 2.2.2.17 --- Effects ofODA on hepatic CETP mRNA --- p.65
Chapter 2.2.2.18 --- Effects of ODA on hepatic LDLR mRNA --- p.65
Chapter 2.2.2.19 --- Effects of ODA on hepatic LXR mRNA --- p.65
Chapter 2.2.2.20 --- Effects of ODA on hepatic CYP7A1 mRNA --- p.65
Chapter 2.3 --- Experiment 2 --- p.70
Chapter 2.3.1 --- Materials and Methods --- p.70
Chapter 2.3.1.1 --- Experimental diets --- p.70
Chapter 2.3.1.2 --- Animals --- p.70
Chapter 2.3.1.3 --- Intestinal acyl coenzyme A: cholesterol acyltransferase (ACAT) activity measurement --- p.70
Chapter 2.3.1.3.1 --- Preparation of intestinal microsome --- p.71
Chapter 2.3.1.3.2 --- ACAT activity assay --- p.71
Chapter 2.3.2 --- Results --- p.73
Chapter 2.3.2.1 --- Growth and food intake --- p.73
Chapter 2.3.2.2 --- Organ weights --- p.73
Chapter 2.3.2.3 --- "Effect of ODA on serum TC, TG and HDL-C" --- p.73
Chapter 2.3.2.4 --- Effect of ODA feeding on fecal neutral sterol content --- p.77
Chapter 2.3.2.5 --- Effect of ODA feeding on fecal acidic sterol content --- p.77
Chapter 2.3.2.6 --- Effect of ODA feeding on intestinal acyl coenzyme A: acyl cholesterol transferase (ACAT) activity --- p.77
Chapter 2.4 --- Discussion --- p.81
Chapter CHAPTER 3 --- EFFECT OF OCTADECAENOIC ACIDS ON CHOLESTEROL-REGULATING GENES IN HepG2
Chapter 3.1 --- Introduction --- p.86
Chapter 3.1.1 --- HepG2 as a model of cholesterol regulation --- p.86
Chapter 3.1.2 --- Effect of polyunsaturated fatty acids (PUFAs) on cholesterol regulating genes in cultured cells --- p.87
Chapter 3.1.3 --- Objectives --- p.89
Chapter 3.2 --- Materials and Methods --- p.90
Chapter 3.2.1 --- Cell culture --- p.90
Chapter 3.2.2 --- "Measurement of SREBP-2, LDLR, HMGR and CYP7A1 protein abundance by Western blotting" --- p.92
Chapter 3.2.3 --- "Measurement of cellular SREBP-2, LDLR, HMGR, LXR, CYP7A1 and CETP mRNA by real time PCR" --- p.93
Chapter 3.2.4 --- Statistics --- p.93
Chapter 3.3 --- Results --- p.95
Chapter 3.3.1 --- Effect of ODA on HepG2 SREBP-2 immunoreactive mass --- p.95
Chapter 3.3.2 --- Effect of ODA on HepG2 HMGR immunoreactive mass --- p.95
Chapter 3.3.3 --- Effect of ODA on HepG2 LDLR immunoreactive mass --- p.95
Chapter 3.3.4 --- Effect of ODA on HepG2 LXR immunoreactive mass --- p.95
Chapter 3.3.5 --- Effect of ODA on HepG2 CYP7A1 immunoreactive mass --- p.96
Chapter 3.3.6 --- Effect of ODA supplementation on HepG2 SREBP-2 mRNA expression --- p.102
Chapter 3.3.7 --- Effect of ODA supplementation on HepG2 SREBP-2 mRNA expression --- p.102
Chapter 3.3.8 --- Effect of ODA supplementation on HepG2 LDLR mRNA expression --- p.102
Chapter 3.3.9 --- Effect of ODA supplementation on HepG2 LXR mRNA expression --- p.106
Chapter 3.3.10 --- Effect of ODA supplementation on HepG2 CYP7A1 mRNA expression --- p.106
Chapter 3.3.11 --- Effect of ODA supplementation on HepG2 CETP mRNA expression --- p.106
Chapter 3.4 --- Discussion --- p.110
Chapter CHAPTER 4 --- EFFECT OF APPLE POLYPHENOLS ON BLOOD CHOLESTEROL IN HAMSTERS
Chapter 4.1 --- Introduction --- p.114
Chapter 4.1.1 --- Apple is a commonly consumed fruit worldwide --- p.114
Chapter 4.1.2 --- Potential health effects of apples --- p.114
Chapter 4.1.3 --- Abundance of polyphenols in apple --- p.115
Chapter 4.1.4 --- Fuji variety of apple --- p.116
Chapter 4.1.5 --- Objectives --- p.116
Chapter 4.2 --- Materials and Methods --- p.118
Chapter 4.2.1 --- Isolation of AP --- p.118
Chapter 4.2.2 --- Characterization of AP extract --- p.118
Chapter 4.2.3 --- Effect of AP on CETP activity in vitro --- p.118
Chapter 4.2.4 --- Effect of AP on blood cholesterol in hamsters --- p.119
Chapter 4.2.4.1 --- Animals --- p.119
Chapter 4.2.4.2 --- Diets --- p.120
Chapter 4.2.4.3 --- Plasma lipids measurement --- p.121
Chapter 4.2.4.4 --- Plasma CETP activity measurement and immunoreactive mass by Western blotting --- p.123
Chapter 4.2.4.5 --- "Measurement of liver SREBP-2, LDL-R, HMG-R and CYP7A1 protein abundance by Western blotting" --- p.124
Chapter 4.2.4.6 --- Statistics --- p.124
Chapter 4.3 --- Results --- p.125
Chapter 4.3.1 --- Polyphenol content in AP --- p.125
Chapter 4.3.2 --- Effect of AP on CETP activity in vitro --- p.125
Chapter 4.3.3 --- Growth and food intake --- p.128
Chapter 4.3.4 --- Organ weights --- p.128
Chapter 4.3.5 --- Effect of AP supplementation on the plasma lipid profile of hamsters --- p.131
Chapter 4.3.6 --- Effect of AP feeding on plasma CETP activity of the hamsters --- p.131
Chapter 4.3.7 --- Effect of AP on plasma CETP immunoreactive mass --- p.134
Chapter 4.3.8 --- Effect of AP on liver SREBP-2 immunoreactive mass --- p.134
Chapter 4.3.9 --- Effect of AP on liver LDLR immunoreactive mass --- p.134
Chapter 4.3.10 --- Effect of AP on liver HMGR immunoreactive mass --- p.134
Chapter 4.3.11 --- Effect of AP on liver CYP7A1 immunoreactive mass --- p.134
Chapter 4.3.12 --- Effect of AP on liver cholesterol level --- p.140
Chapter 4.4 --- Discussion --- p.142
Chapter CHAPTER 5 --- CONCLUSION --- p.145
REFERENCES --- p.148

Sialic acids are involved in many cellular interactions. They can serve as an adhesion ligand or act as an inhibitor to cellular adhesion by charge repulsion or by masking potential ligands. Although sialic acids are implicated in the process of blastocyst implantation, their expression and regulation in uterine epithelium of mice have not been studied. The lectin, Sambucus nigra (SNA) specifically recognizes ��2,6-linked sialic acids, which are involved in cell recognition phenomena. It was used to probe frozen uterine sections from mice during days one through six of pregnancy. SNA staining was most intense at the apical surface of uterine epithelial cells on day one of pregnancy, decreased gradually through day four, and was undetectable by day five. The role of the steroid hormones, estrogen and progesterone, in regulating the expression of ��2,6-linked sialic acids was studied in uterine sections from mice during the estrous cycle and in ovariectomized mice given hormone replacement using SNA. SNA staining of these sections during the estrous cycle showed that the expression of ��2,6-linked sialic acids was stage dependent. Staining was most intense in uterine sections from mice in estrus, and was not detected in sections from mice in diestrus. In ovariectomized mice, staining was most intense in mice injected with estradiol alone, and no staining was evident in mice injected with progesterone alone. These results suggest that the expression of ��2,6-linked sialic acids decreases during the time of implantation and that estrogen stimulates and progesterone inhibits its expression. ��-Galactoside ��2,6-Sialyltransferase (��2,6-ST) is the enzyme that links sialic acids to Gal��1-4GlcNAc termini of N-linked oligosaccharides. In order to investigate the mechanism behind the hormonal regulation of ��2,6-linked sialic acids, the expression of ��2,6-ST was followed in uterine sections from mice during early pregnancy, during the estrous cycle, and in ovariectomized mice given hormone replacement. In-situ hybridization was performed using digoxigenin labeled RNA probes to characterize ��2,6-ST mRNA levels in uterine sections. Expression of ��2,6-ST protein was also measured in uterine sections with a polyclonal antibody against ��2,6-ST. The expression of ��2,6-ST mRNA and protein correlated well with the timing of the appearance of ��2,6-linked sialic acids. These results show that the expression of ��2,6-linked sialic acids on the surface of mouse uterine epithelium decreases at the time of implantation and furthermore, that this decrease is due to the regulation of ��2,6-ST by the steroid hormones. ��2,6-linked sialic acids may serve to inhibit cellular adhesion by creating a charge repulsion, or by masking potential binding sites. Removal of this inhibition may permit blastocyst implantation.
Graduation date: 2001

碩士
國立臺灣大學
食品科技研究所
100
Cerebral ischemia, also known as Stroke, is a disease caused by the rapidly loss of blood supply to brain and which might affect intellectual function such as memory, language skills, perception, or cognitive skills including reasoning and judgment. Many studies have shown that a variety of phenols reduce brain damage on rats induced by brain ischemia and reperfusion. Therefore, the purpose of our study is to find some potential phenols to improve neuron damage in vitro. Oxygen glucose deprivation (OGD), a cell model approximating the conditions associated with cerebral ischemia in vivo, induces cell damage by reducing the supply of oxygen and glucose. The brain requires a continuous supply of oxygen and glucose to maintain normal function and viability. In our study, 10 μM ρ-coumaric acid could increase 14.97% of cell viability and 1 μM Chlorogenic acid increase 9.49% of cell viability after experiencing ischemia-like OGD damage. These two phenolic acids, 10 μM ρ-coumaric acid and 1 μM Chlorogenic acid, decrease 40.71% and 25.80% percentage of autophagy. 10 μM ρ-coumaric acid treatment also elevated 24.90% of intracellular calcium concentration and 1 μM Chlorogenic acid raised 88.65% of intracellular calcium concentration compared with OGD damage alone. We supposed that increase in cell viability of these two phenolic acids was through ameliorating autophagy, and the pathway they regular autophagy was elevating intracellular calcium concentration.

Three experiments were conducted to study the influence of dietary fatty acids on the production performance and immune response of chickens. In experiment I, forty day-old broiler chicks were fed diets containing 5% of either animal fat + conjugated linoleic acid (CLA) (Diet I), sunflower oil (Diet II), flax oil (Diet III) or fish oil (Diet IV). No significant differences (P>0.05) were observed between the live weight of birds. The liver tissue total fat content was lower (P<0.05) in treatment I and II. The fatty acid composition of breast and thigh muscle, liver, heart, pericardial fat, plasma, splenocytes and gut associated lymphoid tissue differed (P<0.05) between treatments. The thiobarbituric acid reactive substances (TBARS) of breast and thigh muscle, liver and heart tissue were lower (P<0.05) in Diet I fed birds. Serum antibody activity was decreased (P<0.05) in Diet II fed birds. In experiment II, 120 day-old broiler chicks were fed diets containing 3.5% of either animal fat + conjugated linoleic acid (CLA) (Diet I), sunflower oil (Diet II), linseed oil (Diet III) or fish oil (Diet IV). Body weight gain was higher (P<0.05) in Diets III and IV compared to Diets I and II fed birds. Feed intake was increased (P<0.05) in Diet IV fed birds. Birds fed Diets III and IV had higher (P<0.05) n-3 fatty acids in all tissues studied. A preferential incorporation of CLA was observed in spleen mononuclear cells. TBARS were higher (P<0.05) in the breast and thigh muscle of Diet IV fed birds. Serum anti-BSA antibody content was higher (P<0.05) in birds fed Diets III and IV. Delayed type hypersensitivity (DTH) response was increased (P<0.05) in Diets IV and III fed birds. Lymphocyte and spleen mononuclear cell CD4⁺, CD8⁺ and IgM⁺ cell population did not differ (P>0.05) among treatments. In experiment III, 120 layer birds were fed diets containing 3% of CLA+animal fat (Diet I), sunflower oil (Diet II), canola+flax oil (Diet III) or fish oil (Diet IV). Egg production, feed consumption and feed efficiency did not differ (P>0.05) among treatments. Birds fed Diets III and IV had higher content of n-3 fatty acids in eggs. Eggs from hens fed Diet I incorporated higher (P<0.05) CLA and saturated fatty acids with a concomitant reduction in (P<0.05) monounsaturated fatty acid content. A preferential incorporation of CLA was observed in eggs over other tissues. TBARS were higher (P<0.05) in breast and thigh muscle of Diet IV fed birds. Egg TBARS content did not differ (P>0.05) among treatments. Serum and yolk anti-BSA antibody contents were higher (P<0.05) in birds fed Diets III and IV. DTH response was increased (P<0.05) in Diets IV and III fed birds. Lymphocyte and spleen mononuclear cell CD4⁺, CD8⁺ and IgM⁺ cell population did not differ (P>0.05) among treatments. Feeding n-3 fatty acids increased antibody mediated immune response while n-6 fatty acids and CLA increased cell mediated immune response.
Graduation date: 2003

The consumption of plant-based beverages can be an excellent way to increase the intake of bioactive compounds promoting consumers’ health. However, unprocessed plant-based beverages have a short shelf life and thermal treatments are usually required, affecting the overall quality of the beverages. High pressure processing (HPP) may be a solution since it has been recognized for retaining nutritional and sensorial quality of fresh foods. The acorn is very abundant in Portugal but still is sub-valorised to the point of staying in the field without any use, despite its high nutritional value, phytochemical compounds, antioxidant, anticarcinogenic, and cardioprotective properties. This work aimed to develop a functional acorn beverage, free of gluten and lactose. Thereafter, the impact of HPP (450 and 600 MPa for 5, 12.5, and 20 min) and conventional thermal processing (85 ºC for 30 min) on the microbiological safety (Enterobacteriaceae, mesophiles, psychrophiles, molds and yeasts, Staphylococcus and lactic bacteria) and physical-chemical characteristics (pH, colour, antioxidant activity, and food compounds) was assessed. The initial acorn leaching reduces in 42.5 % the content of hydrolysable tannins, which are responsible for the undesirable astringency. The pressurized samples maintained microbiological stability over ten weeks of analysis, which was not verified for untreated samples. Moreover, HPP at 450 MPa/5 min was enough to inactivate B. cereus, E. coli and P. aeruginosa. The HPP better preserved the colour (lower ΔE*), but the pH increased after both treatments (from 5.1 to 5.9 and 6.2, for thermal processed and pressurized samples). The degree brix is very low in all samples (0.1 – 1.6 %), with higher values in the thermal processed samples. Total phenolics as well as antioxidant activity (ABTS, DPPH, and ORAC) were similar among the different treatments being gallic acid the main phenolic compound found in this beverage. The total carbohydrates, lipids, and protein contents were similar between the different treatments, as well as the lipid fraction, that shows elevated values of both MUFA and PUFA, namely nutritionally relevant fatty acids like oleic, linoleic, and linolenic. The lipid fraction also reveals low thrombogenicity and atherogenicity indices. This beverage is source of amino acids once it contains all the essential amino acids determinate. Regarding mineral content, potassium was the principal compound quantified but other minerals were found in minor amounts. The absence of 5-hydroxymethylfurfural was confirmed in both treatments. In the sensory analysis performed, the consumers preferred the pressurized treated sample. With this study some tests were performed in order to proceed with the development of a functional beverage with this fruit that is a surplus in Portugal and around the world.
O consumo de bebidas vegetais pode ser uma excelente forma de aumentar a ingestão de compostos bioativos que promovem a saúde. No entanto, as bebidas vegetais não processadas têm um tempo de prateleira curto e geralmente são necessários tratamentos térmicos, afetando a sua qualidade. O processamento por alta pressão (HPP) pode ser uma solução, pois tem sido reconhecido por manter a qualidade nutricional e sensorial de alimentos frescos. A bolota é muito abundante em Portugal, mas ainda é subvalorizada, a ponto de permanecer no campo sem utilidade, apesar de seu elevado valor nutricional, compostos fitoquímicos, propriedades antioxidantes, anticarcinogénicas, e cardioprotetoras. Assim, este trabalho teve como objetivo desenvolver uma bebida funcional de bolota, isenta de glúten e lactose. O impacto do HPP (450 e 600 MPa por 5, 12.5, e 20 min) e do processamento térmico convencional (85 ºC por 30 min) na segurança microbiológica (mesófilos, psicrófilos, bolores e leveduras, Enterobacteriaceae, Staphylococcus, e bactérias lácticas) e características físico-químicas (pH, cor, atividade antioxidante, e compostos antioxidantes) foi avaliado. A lixiviação inicial da bolota reduziu em 42.5 % o teor de taninos hidrolisáveis, responsáveis pela adstringência indesejável. As amostras pressurizadas mantiveram a estabilidade microbiológica ao longo de dez semanas de análise, o que não se verificou para amostras não tratadas. Além disso, o HPP a 450 MPa por 5 min foi suficiente para inativar B. cereus, E. coli, e P. aeruginosa. O HPP preservou melhor a cor (ΔE* menor), mas o pH aumentou após ambos os tratamentos (de 5.1 para 5.9 e 6.2, em amostras processadas termicamente e pressurizadas, respetivamente). O grau brix foi muito baixo em todas as amostras (0,1 – 1,6 %), mas com valores mais altos nas processadas termicamente. Os fenólicos totais e a atividade antioxidante (ABTS, DPPH, e ORAC) foram semelhantes entre os diferentes tratamentos, sendo o ácido gálico o principal composto fenólico detetado. O conteúdo total em hidratos de carbono, lípidos, e proteínas foi semelhante, bem como a fração lipídica, que mostrou elevados valores de MUFA e PUFA, ácidos gordos nutricionalmente relevantes, como oleico, linoleico e linolénico. A fração lipídica revelou também baixos índices de trombogenicidade e aterogenicidade. Esta bebida é fonte de aminoácidos, uma vez que contém todos os aminoácidos essenciais determinados. Em relação ao conteúdo em minerais, o potássio foi o principal composto quantificado, mas outros foram encontrados em menores quantidades. A ausência de 5-hidroximetilfurfural foi confirmada em ambos os tratamentos. Na análise sensorial realizada, os consumidores preferiram a amostra pressurizada. Com este estudo foram realizados alguns ensaios a fim de prosseguir com o desenvolvimento de uma bebida funcional com este fruto que é um excedente em Portugal e no mundo.
Mestrado em Biotecnologia

Hydrotropes, with their ability to increase the solubility of hydrophobic substances in water, can expand the applicability of the greenest and most abundant of all solvents. However, and even though broadening the repertoire of safer solvents is in line with the principles of green chemistry and is essential for a sustainable future, hydrotropy is often overlooked as a promising tool for green chemistry. This is due to a lack of fundamental understanding on its mechanism, which hampers the design of novel hydrotropic systems and limits its applications to a few well-known examples. This work starts by using glycerol ethers as a case-study of hydrotropy by investigating their ability to enhance the solubility of gallic and syringic acids in water. The results obtained suggest that the solubility enhancement ability of a hydrotrope, and by extension its hydrotropic capability, depends on its concentration in water. Furthermore, using the concept of the Setschenow constant, it is shown that the hydrophobicities of both solute and hydrotrope play an important role in the solubility enhancement by hydrotropy. Building on the preliminary results obtained with glycerol ethers, experimental evidence for the cooperative theory of hydrotropy, which holds that hydrotropy occurs due to water-mediated aggregation of hydrotropes around the solute, is obtained here for the first time, using 1H-NMR. Moreover, a new computational approach to quantify apolarity is introduced, and is used to clarify the role of the apolarity of both solute and hydrotrope. In fact, it is shown that the number of hydrotrope molecules aggregated around the solute is maximum when there is a match between the apolarity of the two species. Using these newly-found fundamental concepts of hydrotropy, the solubility of hydrophobic solutes in Cyrene, an emerging bio-based green solvent, and its mixtures with water is herein explored. It is shown that hydrotropy is the solubilization mechanism of hydrophobic solutes in the water-Cyrene system, in most of its concentration range. Furthermore, the ketone form of Cyrene is shown to be the principal hydrotrope of the system, with the diol form acting as a hydrotrope only at low Cyrene concentration. The parameters of the cooperative model are shown to be correlated with the hydrophobicity of the solutes, which is explored to successfully predict the solubility curves of phthalic acid, aspirin, gallic acid and vanillin in water-Cyrene mixtures. Finally, it is shown that water, when added to Cyrene in a small amount, acts as a cosolvent by establishing strong hydrogen bonding with the solute. This shows that a system may solubilize hydrophobic solutes through very different mechanisms, depending on the concentration of each species.
Os hidrótropos, pela sua capacidade de aumentar a solubilidade de substâncias hidrofóbicas em água, podem expandir a aplicabilidade do mais verde e mais abundante de todos os solventes. No entanto, e embora a ampliação do repertório de solventes mais seguros esteja alinhada com os princípios da química verde e seja essencial para um futuro sustentável, a hidrotropia é frequentemente negligenciada como uma ferramenta promissora para a química verde. Isto deve-se à falta de conhecimento fundamental relativo ao seu mecanismo, o que dificulta o desenho de novos sistemas hidrotrópicos e limita a sua aplicação a alguns exemplos bem conhecidos. Este trabalho começa por usar éteres de glicerol como um caso de estudo de hidrotropia, investigando a sua capacidade de aumentar a solubilidade de ácido gálico e siríngico em água. Os resultados obtidos sugerem que a capacidade hidrotrópica depende da concentração do hidrótropo na água. Além disso, usando o conceito da constante de Setschenow, mostra-se que as hidrofobicidades do soluto e do hidrótropo desempenham um papel importante no aumento da solubilidade por hidrotropia. Com base nos resultados preliminares obtidos para os éteres de glicerol, obteve-se aqui, pela primeira vez, usando 1H-RMN, evidência experimental para a teoria cooperativa da hidrotropia, que sustenta que a hidrotropia ocorre devido à agregação de hidrótropos em torno do soluto mediada pela água. Além disso, uma nova abordagem computacional para quantificar a apolaridade é introduzida e usada para esclarecer o papel da apolaridade do soluto e do hidrótropo no mecanismo de hidrotropia. De facto, mostra-se que o número de moléculas de hidrótropo agregadas à volta do soluto é máximo quando há uma correspondência entre a apolaridade de ambas as espécies. Usando os novos conceitos de hidrotropia desenvolvidos ao longo do trabalho, a solubilidade de solutos hidrofóbicos em Cyrene, um solvente verde produzido a partir de fontes renováveis, e suas misturas com água são aqui exploradas. Mostra-se que a hidrotropia é o mecanismo de solubilização de solutos hidrofóbicos no sistema água-Cyrene, na maior parte da sua gama de concentração. Além disso, demonstra-se que a forma cetona do Cyrene é o principal hidrótropo do sistema. Os parâmetros do modelo cooperativo correlacionam-se com a hidrofobicidade dos solutos, o que é explorado para prever com sucesso as curvas de solubilidade do ácido ftálico, aspirina, ácido gálico e vanilina nas misturas água-Cyrene. Finalmente, mostra-se que a água, quando adicionada ao Cyrene em pequena quantidade, atua como um cosolvente, estabelecendo uma forte ponte de hidrogénio com o soluto. Isto mostra que um sistema pode solubilizar solutos hidrofóbicos através de mecanismos muito diferentes, dependendo da concentração de cada espécie.
Mestrado em Engenharia Química

Previous studies suggest that vitamin B-6 supplementation can alter fuel metabolism during exercise and plasma amino acid levels at rest. To examine the effect of vitamin B-6 supplementation on plasma fuel substrates and amino acid levels during exercise, five trained males (age: 29±7; V0₂ max: 54.7±6.2 ml/kg/min) performed two separate submaximal, endurance, exercise tests on a cycle ergometer. Subjects were exercised to exhaustion at 74.5±7.8% V0₂ max in a fasted condition on the seventh morning of two separate nine day controlled diet periods. The first exercise test (T1) occurred following a control or non-supplemented (NS) diet (i.e. 1.9 mg B-6/day), and the second exercise test (T2) occurred following a vitamin B-6 supplemented (S) diet (i.e. 1.9 mg B-6/day + 20 mg PN/day). Blood was drawn pre, during (i.e. 60 minutes into exercise), post, and post-60 minutes of exercise, and plasma was analyzed for glucose, lactic acid, glycerol, free fatty acids (FFA), and amino acids. Expired air was collected for three minutes at 10 minute intervals during both tests. Although not statistically different, there were observed trends for higher mean lactate levels and lower mean glycerol and FFA levels in T2 (S) compared to T1 (NS). Mean lactate, glycerol, and FFA concentrations all changed statistically significantly over time in both exercise tests. Mean plasma tyrosine levels were significantly lower (p = 0.007) at post-60 minutes of exercise and mean plasma methionine levels were significantly lower (p = 0.03) at post-exercise in T2 relative to T1. Of the 13 amino acids quantitated, only alanine and histidine concentrations changed significantly over time. Although not statistically significant, mean respiratory exchange (R) values tended to be higher in T2 compared to T1. Mean oxygen consumption values were significantly higher (p = 0.02) during the first 10 minutes of exercise and at multiple later time points showed a trend for being higher in T2 compared to T1. No statistically significant differences were observed in subjects' performance times to exhaustion between T1 (1:35:49; hr:min:sec) and T2 (1:31:56). These results indicate that vitamin B-6 supplementation can potentially alter fuel metabolism and plasma amino acid levels during exhaustive endurance exercise; however, not to such a degree that one's endurance capacity is affected.
Graduation date: 1995

The DNA repair capabilities of rainbow trout (Salmo gairdneri) were studied vising the method of autoradiography. Trout were fed a semi-purified control diet containing 0 ppm, 50 ppm, or 300 ppm cyclopropenoid fatty acids (CPFA) for 6-9 weeks. Liver slices were prepared and exposed in vitro to a control treatment, ultraviolet irradiation (UV), ethidium bromide (EB), UV/EB in succession, or aflatoxin B₁. The degree of DNA repair was analyzed in terms of net grains per cell. Except following the EB treatment, fish on the control diet revealed an absence of ongoing DNA repair. Trout fed 50 ppm CPFA exhibited a consistently low level of repair over time following the in vitro control treatment. Fish fed 300 ppm CPFA revealed a relatively higher degree of ³H-Me-thymidine incorporation indicative of induced DNA repair following the in vitro control treatment, and the degree of repair increased with time on the diet. UV-irradiation caused a marked increase in the degree of induced DNA repair in 300 ppm CPFA fish at 6 and 7.5 weeks, and in 50 ppm CPFA fish at 7.5 weeks. Follcwing UV-irradiation, liver slices were exposed to EB, a DNA intercalating agent used to inhibit normal DNA replication. However, in contrast to the desired effect, EB caused a marked decrease in the degree of repair synthesis observed in 300 ppm CPFA fish at 6 and 7.5 weeks. Indicative of intercalation, the in vitro EB treatment caused a moderate degree of ³H-Me-thymidine incorporation in fish fed the control diet. Repair was also induced in 300 ppm CPFA fish following exposure to EB at 6 and 7.5 weeks. Aflatoxin B₁ induced DNA repair to various degrees in fish on all diets at 7.5 and 9 weeks. In comparison to the in vitro control treatment, it was observed that the degree of induced DNA repair was decreased significantly - "completely" following the UV, UV/EB, and EB treatments - in fish fed the 300 ppm CPFA diet for 9 weeks. In view of the low level of DNA repair observed in rainbow trout using autoradiography, the repair capabilities were studied using a more sensitive assay, bromodeoxyuridine (BrdU) photolysis. Isolated hepatocytes were prepared from fish fed the various diets and exposed in vitro to a control treatment, UV-irradiation, or 4-nitroquinoline-N-oxide. The obtained results were nonconclusive indicating technical improvements on the assay need to be made.
Graduation date: 1988

Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are polyunsaturated fatty acids required for proper embryonic development, specifically neurodevelopment. However, little is known regarding their conversion to other metabolites during embryogenesis. The oxidation of ARA gives rise to the biologically active eicosanoids and the oxidation of DHA gives rise to the biologically active docosanoids. The oxidation of ARA and DHA occurs through enzymatic processes, via lipoxygenase (LOX), or non-enzymatic processes, via radical-mediated lipid peroxidation. We hypothesize that oxidation of ARA and DHA via LOX is required for proper embryonic development. Additionally, we hypothesize that α-tocopherol, a potent lipid soluble antioxidant, mediates the conversion of ARA and DHA to their respective oxidized metabolites. Using zebrafish as a model of vertebrate embryogenesis, we found that the selective knockdown of either 12-LOX or 5-LOX decreased the production of docosanoids, altered fatty acid homeostasis, and increased the incidence of malformations and mortality in embryos by 24 hours post fertilization. α-Tocopherol deficiency also increased the incidence of malformations and mortality during embryogenesis, and in its absence, increased oxidized metabolites of ARA and DHA and decreased fatty acids concentrations. Therefore, oxidized metabolites of ARA and DHA perform crucial functions during embryonic development, but the production of oxidized fatty acids must be balanced with antioxidant bioavailability for proper embryogenesis.
Graduation date: 2012

Includes bibliographical references (leaves 237-257).
xx, 257 leaves : ill. ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Investigates the mechanisms underlying the antiarrhythmic effects of omega-3 polyunsaturated fatty acids using adult rat ventricular cardiac myocytes.
Thesis (Ph.D.)--Adelaide University, Dept. of Physiology, 2001

by Kwan Kwok Yiu.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1997.
Includes bibliographical references (leaves 145-155).
Acknowledgment --- p.i
Abstract --- p.ii
List of Tables --- p.vii
List of Figures --- p.x
List of Abbreviations --- p.xii
Chapter Chapter 1 --- Literature review
Chapter 1.1 --- Historical background --- p.1
Chapter 1.2 --- Chemistry of trans and cis fatty acids --- p.3
Chapter 1.3 --- Dietary source of trans fatty acids --- p.6
Chapter 1.4 --- Consumption of trans fatty acids among Western countries --- p.9
Chapter 1.5 --- Current health concern for excessive intake of trans fatty acids --- p.10
Chapter 1.6 --- Metabolism of trans fatty acids --- p.13
Chapter 1.6.1 --- Absorption --- p.15
Chapter 1.6.2 --- Oxidation --- p.15
Chapter 1.6.3 --- Incorporation --- p.16
Chapter 1.6.4 --- Selectivity --- p.17
Chapter 1.7 --- Impact of trans fatty acids on essential fatty acid metabolism --- p.19
Chapter 1.8 --- Desaturation and elongation of trans fatty acids --- p.21
Chapter 1.9 --- Trans fatty acids and neonatal growth --- p.23
Chapter Chapter 2 --- Amount of trans fatty acids in Hong Kong fast foods
Chapter 2.1 --- Introduction --- p.25
Chapter 2.2 --- Objective --- p.25
Chapter 2.3 --- Materials and methods --- p.26
Chapter 2.4 --- Results --- p.27
Chapter 2.5 --- Discussion --- p.31
Chapter Chapter 3 --- Cross-cultural study of trans fatty acids in human milk
Chapter 3.1 --- Introduction --- p.35
Chapter 3.2 --- Objective --- p.35
Chapter 3.3 --- Materials and methods --- p.36
Chapter 3.4 --- Results
Chapter 3.4.1 --- Dietary information --- p.38
Chapter 3.4.2 --- Fatty acid composition of Chinese and Canadian human milk --- p.40
Chapter 3.4.3 --- Difference between Chinese and Canadian human milk --- p.40
Chapter 3.4.4 --- Difference between Hong Kong and Chongqing Chinese human milk --- p.43
Chapter 3.4.5 --- The change in milk fat and LCPUFA as lactation progresses --- p.43
Chapter 3.5 --- Discussion
Chapter 3.5.1 --- Trans fatty acids in human milk --- p.46
Chapter 3.5.2 --- Content of LCPUFA in human milk --- p.47
Chapter 3.5.3 --- Content of 18:2n-6 in human milk --- p.48
Chapter 3.5.4 --- Fat content in Hong Kong and Chongqing Chinese human milk --- p.49
Chapter 3.6 --- Conclusion --- p.50
Chapter Chapter 4 --- Trans fatty acids and maternal and neonatal essential fatty acid metabolism
Chapter 4.1 --- Introduction --- p.51
Chapter 4.2 --- Objectives --- p.53
Chapter 4.3 --- Materials and methods --- p.53
Chapter 4.4 --- Results
Chapter 4.4.1 --- Experiment1
Chapter 4.4.1.1 --- Relationship between the trans fatty acids in maternal diet and those in milk --- p.64
Chapter 4.4.1.2 --- Relationship between the trans fatty acids in maternal diet and those in neonatal liver --- p.64
Chapter 4.4.1.3 --- Content of 20:4n-6 in milk and in neonatal liver relative to that in maternal diet --- p.72
Chapter 4.4.2 --- Experiment2
Chapter 4.4.2.1 --- Amount of trans fatty acids in rat milk --- p.75
Chapter 4.4.2.2 --- Trans fatty acids in rat liver phospholipids --- p.75
Chapter 4.4.2.3 --- Linoleic acid (18:2n-6) content in rat and its relation to maternal diets --- p.86
Chapter 4.4.2.4 --- Content of 20:4n-6 in rat milk --- p.86
Chapter 4.4.2.5 --- Content of20:4n-6 in rat liver --- p.89
Chapter 4.4.2.6 --- Suppression of the synthesis of 20:4t isomers in maternal and neonatal liver --- p.89
Chapter 4.5 --- Discussion
Chapter 4.5.1 --- Relationship between fatty acid composition of diet and that of milk --- p.93
Chapter 4.5.2 --- 20:4n-6 in rat milk --- p.95
Chapter 4.5.3 --- Transfer of trans fatty acids from maternal diet to neonatal liver phospholipids --- p.98
Chapter 4.5.4 --- The inhibitory effect of trans fatty acids on synthesis of 20:4n-6 in neonatal liver --- p.99
Chapter 4.5.5 --- Effect of 18:2n-6 supplement on 20:4n-6 level of neonatal liver --- p.101
Chapter 4.5.6 --- Suppression of 18:2n-6 supplement on synthesis of 20:4t isomers --- p.101
Chapter 4.6 --- Conclusion --- p.104
Chapter Chapter 5 --- Accumulation and turnover of trans fatty acids
Chapter 5.1 --- Introduction --- p.105
Chapter 5.2 --- Objective --- p.105
Chapter 5.3 --- Materials and methods --- p.106
Chapter 5.4 --- Results
Chapter 5.4.1 --- Accumulation of trans fatty acids in liver and adipose tissue --- p.108
Chapter 5.4.2 --- Selectivity of individual 18:2 trans isomersin liver and adipose tissue --- p.112
Chapter 5.4.3 --- Turnover of trans fatty acids --- p.112
Chapter 5.4.4 --- Accumulation and turnover of 18:lt in brain --- p.115
Chapter 5.5 --- Discussion
Chapter 5.5.1 --- Accumulation of trans fatty acids in liver and adipose tissue --- p.120
Chapter 5.5.2 --- Turnover of trans fatty acids --- p.122
Chapter 5.5.3 --- Accumulation and turnover of trans fatty acidsin brain --- p.124
Chapter 5.6 --- Conclusion --- p.125
Chapter Chapter 6 --- In vivo Oxidation of trans fatty acids in rat
Chapter 6.1 --- Introduction --- p.126
Chapter 6.2 --- Objective --- p.127
Chapter 6.3 --- Materials and methods --- p.127
Chapter 6.4 --- Results --- p.129
Chapter 6.4.1 --- Apparent oxidation of saturated fatty acids --- p.136
Chapter 6.4.2 --- Apparent oxidation of 18:lt relative to 18:ln-9 --- p.136
Chapter 6.4.3 --- Oxidation of 18:2t isomers relative to 18:2n-6 --- p.137
Chapter 6.4.4 --- Effect of 18:2n-6 supplement in PHCO diet on oxidation per se --- p.137
Chapter 6.5 --- Discussion --- p.138
Chapter 6.5.1 --- Oxidation of 18:lt and 18:2t isomers --- p.139
Chapter 6.5.2 --- Effect of 18:2n-6 supplement on oxidation per se --- p.140
Chapter 6.6 --- Conclusion --- p.141
General conclusion --- p.142
References --- p.145

Epidemiological studies have suggested that the consumption of fish may reduce the risk of cardiovascular disease. Compared to the number of studies using fish oils, few studies have used fish itself. Those which have used fish have generally used fattier fish such as mackerel and salmon as part of an uncontrolled diet. In this study, 23 healthy men consumed 200g each of Chinook salmon, Dover sole, and sablefish in a three-way crossover design for 18-day periods with three-week washout periods in between. The diets had the approximate composition of the 'Western' diet: 45% carbohydrates, 36% fat, and 16% protein with the sole diet containing 1.95 g omega-3 (n-3) fatty acids, the salmon diet 3.99 g n-3, and the sablefish diet 3.42 g n-3 fatty acids. Serum total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), bleeding time (BT), blood pressure (BP), platelet aggregation (PA) using ADP and collagen as agonists, platelet fatty acid profiles (FAP), thromboxane B2 (TXB2) , and apolipoprotein B (Apo B) were measured at the beginning and end of each period. TC, and HDL-C, and TG changed significantly when compared to the prefish diet while both LDL-C and apo B demonstrated diet effect. LDL-C increased on both the salmon and sablefish diets (p = 0.08) compared to the sole diet, and increased approximately 15% on the former two diets compared to the prefish diet. Bleeding time was significantly longer when the salmon diet was consumed (p = 0.06). The impact of the three diets on PA depended upon the agonist. With collagen, only the sablefish diet decreased aggregation compared to the prefish diet. When ADP was used, aggregation decreased on both the fattier fish diets compared to the low fat fish (sole). Similar results were demonstrated for TXB₂: the fattier fish produced statistically equivalent decreases (p = 0.06) among the diets, and lowered TXB₂ compared to the prefish diet. There were no significant differences among the diets for either systolic or diastolic BP though there was a significant decrease (p = 0.01) in diastolic pressure compared to the prefish diet when the salmon diet was consumed. Platelet fatty acid profiles reflected diet composition.
Graduation date: 1993

We have previously shown that diets enriched with (n-3) fatty acids reduced the delayed-type hypersensitivity (DTH) skin reaction to keyhole limpet haemocyanin (KLH) in geriatric-Beagles. Although the amount of ��-tocopheryl acetate in diets of the previous study exceeded requirements, plasma ��-tocopherol concentration was significantly lower in dogs fed the high (n-3) fatty acid diets. There are several reasons that could explain the decreased DTH response. Some of these include decreased cytokine production, specifically, interleukin (IL) IL-1��, tumor necrosis factor (TNF) and IL-6 by mononuclear cells. Furthermore, the reduced DTH response could be attributed to increased levels of lipid peroxides or changes in plasma ��-tocopherol levels. In this study we examined the effects of feeding 32 healthy, female, geriatric-Beagles diets containing (n-6) to (n-3) fatty acid ratios of 37:1 and 1.7:1, while varying the content of ��-tocopheryl acetate, [high (447 ug/g), med (101 ug/g) and low (17 ug/g)] for 82 days on the DTH reaction. Consumption of the 1.7:1 fatty acid diets significantly increased the total content of (n-3) fatty acids in plasma compared to the 37:1 fatty acid diets (17.00 and 2.02 wt %, respectively). There was a significant interaction between the (n-6) and (n-3) fatty acid ratio and the concentration of ��-tocopheryl acetate in the diet on the plasma concentration of ��-tocoopherol. The concentration of ��-tocopheryl acetate in plasma of dogs fed the 1.7:1 fatty acid diets was 17.3, 25.4, and 35.4 ug/ml, respectively, for the low, med and high ��-tocopheryl acetate containing diets, and in dogs fed the 37:1 fatty acids diets was 20.8, 34.9, 52.4 ug/ml, respectively. Consumption of the 1.7:1 fatty acid diets with either low or high ��-tocopheryl acetate showed no differences in DTH response from each other or from dogs consuming the 37.1:1 fatty acid diets. When the dietary ��-tocopheryl acetate concentration was moderate, a significant suppression of the DTH response occurred at 48, 72, and 96 hr in dogs consuming the 1.7:1 fatty acid diet. These data suggest that an interaction exits between dietary (n-3) fatty acid content and ��-tocopheryl acetate on the immune response as measured by the DTH test.
Graduation date: 2000

Numerous dietary factors have been shown to influence the fatty acid profiles (FAP) in breast milk from lactating women. However, few studies have evaluated the effect of trace minerals on milk FAP. Consequently, the purpose of this study was to determine the effect of selenium status on the FAP in breast milk. Subjects were lactating women from three different regions in China; Xichang (n=21), an area where selenium intakes are among the lowest in the world, Beijing (n=20), where there are adequate selenium intakes, and Enshi (n=19), where selenium intakes are among the highest in the world. Plasma and milk samples were obtained from women at birth of their baby and within 10 months postpartum and analyzed for selenium content, glutathione peroxidase (Gpx) activity and FAP. Plasma and breast milk selenium levels were significantly lower in the Xichang women and significantly higher in the Enshi women when compared to Beijing women. Despite the fact that the highest level of plasma selenium was measured in the samples from Enshi, the Gpx activity was greatest in the samples from Beijing; there was no effect of time of sampling on these samples. In breast milk, on the other hand, all the samples obtained at birth had similar activity of Gpx. The samples taken later, however, followed the same trend as plasma with the samples obtained from the women in Beijing having the highest activity. FAP indicated a significant difference in the amount of unsaturated fatty acids in both the plasma and milk for the Beijing women, when compared to the women from Xichang and Enshi. In particular, there were higher levels of linoleic acid, 18:2(n-6), in the plasma and milk of the women whose selenium intake was adequate.
Graduation date: 1997