Academic literature on the topic 'Grape seed extract (GSE)'

In this study, the effects of grape seed extract on insulin, adiponectin and resistin levels in diabetic rats were aimed to investigate. Weight of about 300-350g 7-8 weeks 32 female Wistar Albino rats were used. Weight of about 300-350g 7-8 weeks 32 female Wistar Albino rats randomly divided into four groups of eight each: control group (C), group with diabetes (DM), grape seed extract group (GSE), diabetes mellitus and grape seed extract group (DM+GSE). The diabetic group 45 mg/kg single dose of streptozotocin was administered intraperitoneally, and the grape seed extract groups (DM+GSE and GSE) grape seed extract was given orally every day with an intragastric tube for 20 days (0.6 ml/rat). Blood samples were taken from the hearts of rat’s end of the experiment. The sera obtained were used for insulin, adiponectin and resistin analysis measured via ELISA with commercial kits. The insulin and adiponectin levels of the rats in the diabetes + grape seed extract group were found to be higher than those in the diabetes group. There was no significant change in the resistin level differences between the groups. As a result; It is possible to say that grape seed extract has an increasing effect on insulin level and adiponectin levels of diabetic rats are decreased due to diabetes and it has no significant effect on resistin levels. Detected by the positive effects of grape seed extracts, it may be useful to use for the regulating of the diabetes in human.

Natural antimicrobials, such as grape seed extract (GSE) and garlic extract (GE), are often used as (a part of) novel food preservation technologies, especially due to their antilisterial effect. However, little is known on the extent of sublethal injury (SI) these extracts cause to Listeria monocytogenes, possibly leading to overestimated efficacies for such novel technologies. The influence of both extracts on the sublethal injury of L. monocytogenes strain LMG23775 was investigated, also using propidium iodide staining to investigate the nature of the injury. Minimum inhibitory concentrations were 500 mg gallic acid equivalents (GAE)/L and 7.5 μg allicin/mL for GSE and GE, respectively. These concentrations slowed down the growth of L. monocytogenes, while only causing a significant amount of SI for GSE. Pure extracts caused inactivation of the cells, with GSE being the most effective. Sublethal injury from pure GSE was mainly caused by membrane damage. In pure GE, a significant amount of SI, not caused by membrane damage, was also present, albeit less pronounced than in pure GSE. In conclusion, both extracts cause a significant amount of sublethal injury to L. monocytogenes, which is not taken into account in relevant studies investigating novel food preservation applications involving natural plant extracts.

ABSTRACT Although flavonoids manifest a diverse range of biological activities, including antitumor and antiviral effects, the molecular mechanisms underlying these activities await elucidation. We hypothesize that the flavonoid constituents of a proprietary grape seed extract (GSE) that contains procyandins exert significant antiviral and antitumor effects, by inducing production of the Th1-derived cytokine gamma interferon (IFN-γ) by peripheral blood mononuclear cells) from healthy donors. Our results show that GSE significantly induced the transcription of IFN-γ mRNA as demonstrated by reverse transcription-PCR but had no effect on the Th2-derived cytokine interleukin-6. The enhancing effect of GSE on IFN-γ expression was further supported by a concomitant increase in the number of cells with intracytoplasmic IFN-γ as well as the synthesis and secretion of IFN-γ. Our results demonstrate that the potentially beneficial immunostimulatory effects of GSE may be mediated through the induction of IFN-γ.

ABSTRACTGrape seed extract (GSE) is reported to have many pharmacological benefits, including antioxidant, anti-inflammatory, anticarcinogenic, and antimicrobial properties. However, the effect of this inexpensive rich source of natural phenolic compounds on human enteric viruses has not been well documented. In the present study, the effect of commercial GSE, Gravinol-S, on the infectivity of human enteric virus surrogates (feline calicivirus, FCV-F9; murine norovirus, MNV-1; and bacteriophage MS2) and hepatitis A virus (HAV; strain HM175) was evaluated. GSE at concentrations of 0.5, 1, and 2 mg/ml was individually mixed with equal volumes of each virus at titers of ∼7 log10PFU/ml or ∼5 log10PFU/ml and incubated for 2 h at room temperature or 37°C. The infectivity of the recovered viruses after triplicate treatments was evaluated by standardized plaque assays. At high titers (∼7 log10PFU/ml), FCV-F9 was significantly reduced by 3.64, 4.10, and 4.61 log10PFU/ml; MNV-1 by 0.82, 1.35, and 1.73 log10PFU/ml; MS2 by 1.13, 1.43, and 1.60 log10PFU/ml; and HAV by 1.81, 2.66, and 3.20 log10PFU/ml after treatment at 37°C with 0.25, 0.50, and 1 mg/ml GSE, respectively (P< 0.05) in a dose-dependent manner. GSE treatment of low titers (∼5 log10PFU/ml) at 37°C also showed viral reductions. Room-temperature treatments with GSE caused significant reduction of the four viruses, with higher reduction for low-titer FCV-F9, MNV-1, and HAV compared to high titers. Our results indicate that GSE shows promise for application in the food industry as an inexpensive novel natural alternative to reduce viral contamination and enhance food safety.

Because of the side-effects of commonly used anti-platelet and anticoagulant drugs, investigations into plant substances with similar activities are very common. Based on our own studies in recent years, we estimate that it is possible to use natural compounds to both inhibit coagulation pathway enzymes and to reduce blood platelets’ activation. As such, in our current study we wanted to verify the anti-platelet and anticoagulant properties of grape seed extract (GSE) using in vitro models. During our analysis, the following parameters were analyzed: Coagulation times, thromboelastometry assays (coagulation time, clot formation time and maximum clot firmness), aggregation of platelets and phosphorylation of vasodilator-stimulated phosphoprotein (VASP). Adenosine diphosphate (ADP)-induced aggregation was lower in GSE 7.5 µg/mL as well as in GSE 15.0 µg/mL. A similar dependence was observed in VASP assays for GSE 7.5 µg/mL and GSE 15 µg/mL. The effect on plasma coagulation tests was distinct only with GSE 15 µg/mL. All of the thromboelastometry variables were statistically significant with 15.0 µg/mL GSE concentration. Our results show, for the first time, the multi-potential effect of grape seed extract on coagulation systems, and clearly suggest that grape seed extract could be considered a promising nutraceutical in the prevention of cardiovascular thrombotic events caused by different mechanisms.

Background Grape seed extract (GSE) has demonstrated various pharmacological actions. Urolithiasis is the occurrence of calculus in the renal system. The present study evaluated the anti-urolithic effect of GSE on ethylene glycol (EG) and ammonium chloride (AC)-induced experimental urolithiasis in rats. Materials and Methods Rats were assigned into six groups; Normal control and Normal + GSE, in which rats received standard drinking water and GSE orally daily, respectively; Urolithiatic animals received EG with AC in drinking water for 28 days; Urolithiatic animals + GSE, in which rats were administered EG with AC in drinking water and GSE 100 and 200 mg/kg orally; and Urolithiatic + cystone, where rats received EG with AC in drinking water and 750 g/kg of cystone as a standard drug orally. Results Urolithiatic animals showed a significant decrease in excreted magnesium and citrate and antioxidant enzymes, whereas they exhibited amplified oxalate crystal numbers, urinary excreted calcium, phosphate, oxalate ions, uric acid, intensified renal function parameters, lipid peroxidation, and inflammatory mediators. Management with GSE and cystone significantly augmented urolithiasis inhibitors (excreted magnesium and citrate) and amplified the antioxidant enzymes’ activities. GSE reduced oxalate crystal numbers and urolithiasis promoters, including excreted calcium, oxalate, phosphate, and uric acid excretion, lessened renal function parameters, and declined lipid peroxidation and the inflammatory mediators. Conclusion GSE could protect against EG-induced renal stones as evidenced by mitigated kidney dysfunction, histological alterations, and oxalate crystal formation. This action may be related to the antioxidant as well as anti-inflammatory activities of the extracts.

The objective of this study was to evaluate the effects of administering a grape seed extract, rich in polyphenols in an experimental model of ligature induced periodontitis in rats. Methods: 30 male Wistar rats were divided into Control group, Ligature group and Grape seed extract (GSE) group. Periodontitis was induced by placing a wire ligature around the first mandibular molar for 4 weeks. The animals in the GSE group were administered grape seed extract by gavage. In days 1, 7 and 28 blood samples were taken and in day 28 the hemimandibles were harvested and sent for histological examination. Reduced glutathione (GSH) and malondialdehyde (MDA) were determined in serum and in gingival tissue. Results: Significantly higher values of MDA were found in serum and periodontium in the Ligature group in comparison to the GSE group. GSE administration resulted in an increase of GSH plasma concentration in the GSE group as compared to the Control and Ligature groups. In the GSE group inflammation and bone involvement were less marked than in the Ligature group. Conclusions: The grape seed extract proved protective anti-inflammatory and antioxidant effects in a ligature-induced experimental model of periodontitis in rats and also improved the histological status of gingival tissue and bone.

Abstract The aim of this work is to evaluate the role of Grape Seed extracts (GSE) from three grape cultivars (Ahmer, Halawani, and Kamali) grown in Iraq as well as pomace on lipid profile in diabetic mice. Fifty adult female mice were divided into five groups. Negative control (untreatment), positive control (treated) diabetic, and diabetic mice treated with GSE. After six weeks; serum and liver tissue homogenate parameters were evaluated. HPLC results showed that Ahmer (red grape seeds) has highest concentration of proanthocyanidins polymers catechine, procyanidin, and epicatechine (796, 170, and 244) μg/g, respectively For that it was chosen for mice dosage, while the lowest amounts were in pomace 489, 99, and 143 μg/g, respectively. Oral dose of grape seed natural extract (600 mg/kg/day) reduced the level of lipid profile: TC, TG, LDL, and VLDL, (106.83±2.13, 84.66±4.27,13.83±1.16 and 21.33±1.21) respectively, except HDL which respectively was increased to 76.33±1.03. GSE were normalized the elevated levels of kidneys and liver functions. Similarly, Liver histological analysis shows that GSE groups exhibited morphology near to that of the control group.

Composition and antioxidant activity of grape seed extract (GSE) obtained from red grape varietes are very well documented, in contrast to the white varietes. This paper presents the results of polyphenols content of ethyl acetate extract of grape seeds, obtained from two white grape varieties, Italian Riesling and Zupljanka, and their antioxidant activity on the stable DPPH radical. The influence of the addition of GSE to raspberry juice on the DPPH radical was also examined. Content of total polyphenols in GSEs ranged between 81.6 and 82.8% (w/w), and the contetn of flavan-3-ols between 66.2 and 91.0% (w/w). HPLC results showed that the most abundant components in the extract were (+)-catechin and (-)-epicatechin for both grape varieties. All tested GSEs exhibited good antioxidant activity. IC50 values for the GSEs of Italian Riesling and Zupljanka were 0.79 and 0.95 mg sample/mg DPPH radical, respectivelly. Since the GSE of Italian Riesling possesed stronger antioxidant activity, it was used for further experiments. The IC50 value for raspberry juice was 4.18 mg raspberry juice/mg DPPH. The raspberry juice with addition of 0.60 ?g/mL of GSE showed antioxidant activity of 39.2%. The same juice with the threefold concentration of vitamin C (1.81 ?g/ml) exhibited similar antioxidant activity (33.9%). Antioxidant activity of the same amount of juice without added antioxidants was lower (15.7%). The results showed that the GSE of white varietes could be considered as a good functional food ingredient.

GSEs (grape seed extracts) which contain polyphenolic compounds cause an endothelium-dependent relaxation of blood vessels. The aim of the present study was to examine the mechanisms involved in this response. A well-characterized GSE was applied to rabbit aortic rings suspended in organ baths containing Krebs–Henseleit buffer maintained at 37 °C. In aortic rings pre-contacted with noradrenaline (norepinephrine), the extract produced a dose-dependent relaxation. The maximum relaxations elicited by the extract (71.9±1.0%) were similar to those elicited by acetylcholine (64.2±1.5%) (n=12 for each). As expected, the relaxations were abolished by removal of the endothelium and by prior incubation with L-NAME (NG-nitro-L-arginine methyl ester), confirming the essential role of eNOS (endothelial NO synthase) in the response. The responses to the GSE were also abolished by incubation with wortmannin and LY294002, which are inhibitors of PI3K (phosphoinositide 3-kinase). These compounds had no effect on the responses to acetylcholine. Using immunoblotting, we also demonstrated that the GSE induced the phosphorylation of both Akt and eNOS in HUVECs (human umbilical vein endothelial cells). Finally, the extract was modified by methylation of the hydroxy groups in the polyphenolic groups and was applied to the aortic rings. The modified extract failed to cause a relaxation. Taken together, these findings suggest that the endothelium-dependent relaxation induced by the GSE was mediated by activation of the PI3K/Akt signalling pathway through a redox-sensitive mechanism, resulting in phosphorylation of eNOS.

Dietary polyphenols have been positively correlated to the reduced risk of several chronic diseases, including Alzheimer' disease (AD). Grape (Vitis vinifera) seed contains 5-8 % polyphenols and annually, 2.5 million tonnes of grape seed is generated in the juice and wine industry. Grape seed extract (GSE) and its compounds gallic acid (GA), resveratrol (RSV) and epigallocatechin gallate (EGCG) have been shown to attenuate AD aetiological features including oxidative stress, protein aggregation, and mitochondrial dysfunction in cell and animal models. The main objectives of this work were to optimize the methods for grape seed polyphenol extraction and assess their antioxidant properties. Polyphenols from grape seeds were extracted using ethanol, methanol, and acetone as solvents. Total phenolic content (TPC), and total flavonoid content (TFC) of GSEs were determined by Folin-Ciocalteu’s and AlCl3 colorimetric methods. Free radical scavenging activities were measured using standard antioxidant assays (DPPH and ABTS) and levels of GA, EGCG, and RSV were determined by high performance liquid chromatography (HPLC). Findings from this study showed the highest TFC levels in acetone extraction that was consistent with previous studies. Ethanol showed improved extraction of phenolic compounds compared to acetone and better than methanol in overall polyphenol extraction. Ethanol extracted GSEs exhibited high free radical scavenging capacity measured using ABTS and DPPH demonstrating its potent antioxidant activity. Ethanol extracted GSEs displayed the highest ABTS scavenging ability as compared to acetone and methanol extractions. Ethanol extracted GSEs showed high free polyphenols content but low level of bound polyphenols. The TFC, TPC and radical scavenging properties of the free polyphenol fraction was significantly higher than those of the bound polyphenol fraction from GSE. Thus, potential therapeutic effects of GSE may be attributed to the free polyphenol fraction. GA and EGCG were detected in both unbound and bound phenolic extracts. However, RSV was only detected in bound polyphenol extract. Overall, the findings presented here have unravelled new insights into the polyphenol content of GSEs, solubility, efficiency of different extraction conditions and more importantly generated new knowledge that will be critical for developing industrial processes for developing GSE as a commercial food product for alleviating AD.

La sclérose en plaques (SEP) est une maladie auto-immune du système nerveux central générant de nombreux symptômes neurologiques, parmi lesquels la douleur chronique qui est très invalidante et fréquente. A ce jour, la SEP est une maladie incurable avec une étiologie complexe, multifactorielle et encore mal comprise. De nombreuses données suggèrent que les polyphénols végétaux pourraient avoir des bénéfices thérapeutiques en régulant le stress oxydant et la neuroprotection dans la SEP. Dans ce contexte, ce travail de thèse a pour objectif d’évaluer l'effet d’un traitement curatif chronique à l'extrait de pépins de raisin (GSE pour Grape Seed Extract) dans un modèle murin reproduisant certaines des caractéristiques cliniques et neuropathologiques de la SEP, l'encéphalomyélite auto-immune expérimentale (EAE). Dans un premier temps, la composition biochimique du GSE a été évaluée. Par la suite, le traitement des souris EAE par le GSE 10 jours après l’induction du modèle (J10) a montré une amélioration à la fois du score neurologique et des troubles sensitifs chez les souris. Des analyses biochimiques et moléculaires au niveau du cerveau et de la moelle épinière ont montré dès J20 une correction des anomalies du stress oxydant permettant une restauration des altérations de la myéline, de la prolifération astrogliale et microgliale et des niveaux d’expression des sirtuines. Enfin, une analyse protéomique a permis de confirmer ces résultats et d’envisager des mécanismes d’action bénéfiques supplémentaires du GSE, notamment la correction de la dégradation des lipides. L’ensemble des effets du GSE décrits au cours de cette thèse soutient fortement l'idée que le GSE pourrait être une approche thérapeutique efficace pour le traitement de la SEP<br>Multiple sclerosis (MS) is an autoimmune disease of the central nervous system leading to many neurological symptoms, among which chronic pain is common and very disabling. To date, MS is an incurable disease with a complex, multifactorial and still poorly understood etiology. Numerous evidence suggest that plant polyphenols may have therapeutic benefits in regulating oxidative stress and providing neuroprotection in MS. In this context, this thesis work aimed to evaluate the effect of a chronic curative treatment with grape seed extract (GSE) in a mouse model reproducing some of clinical and neuropathological features of MS, the experimental autoimmune encephalomyelitis (EAE).First, the biochemical composition of GSE was evaluated. Subsequently, the treatment with GSE initiated from day 10 post-induction (D10) showed both an improvement in the neurological score and sensory disorders in mice. Biochemical and molecular analyzes in the brain and spinal cord showed from D20 a correction of oxidative stress abnormalities allowing restoration of myelin alterations, astroglial and microglial proliferation and levels of sirtuins expression. Finally, a proteomic analysis allowed to confirm these results and to identify new additional beneficial effect of GSE, such as the correction of lipid degradation. All the effects of GSE described during this thesis strongly supports the idea that GSE could be an effective therapeutic approach for the treatment of MS

Grape seed extract (GSE) and peanut skin extract (PSE) are waste products in the wine and peanut industries. Both extracts have high concentrations of polyphenols, known to possess antioxidant and antimicrobial properties. A subcategory of polyphenol is procyanidin, which can be divided into two types, type A and type B. Type A (PSE), contains two single bonds connecting the phenolic groups while type B (GSE), contains one single bond connecting the phenolic groups. The minimum inhibitory concentration (MIC) of the two extracts was evaluated for their antimicrobial effect on Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella Typhimurium using the pour plate method. GSE was found to have a significantly lower MIC (p ≤ 0.05) than PSE for L. monocytogenes (GSE=60.60ppm, PSE=not found), S. aureus (GSE=38.63ppm, PSE=51.36ppm), and S. Typhimurium (GSE=45.73ppm, PSE=60.60ppm). There was no significant difference in inhibition of E. coli O157:H7 (GSE=47.44ppm, PSE=51.13ppm). Since GSE, contributed to greater pathogen inhibition, its extract was fractionated into monomer and oligomers components. Growth curves of all four pathogens inoculated in the monomer and oligomer fractions were compared using the BioScreen method. Oligomers inhibited growth of L. monocytogenes, S. aureus, and E. coli O157:H7 while monomers inhibited growth of S. Typhimurium. These results indicate that an extract with type B procyanidins that are high in oligomers may be more effective as antimicrobials. Type B procyanidins have also been shown to prevent bacterial adhesion, as is the case with urinary tract infections, and may aid in the prevention of biofilms.<br>Master of Science in Life Sciences

Donats els problemes de salut associats al sobrepès, en aquesta tesi hem investigat el possible us d'un extracte de proantocianidines de pinyol de raïm (GSPE) com agent saciant, fent servir rates com a model d'experimentació. Hem observat que sota una pauta d'administració adequada, el GSPE disminueix la ingesta tant de manera aguda com de manera continuada, durant períodes de 8 dies consecutius. Aquestes propietats saciants, sumades a un efecte lipolític, resulten en un descens significatiu del pes corporal. A l'investigar les vies de senyalització implicades, hem observat que l'administració de GSPE modifica la producció i secreció de diverses hormones gastrointestinals que afecten l'apetit, entre les que destaquen el GLP-1, d'efectes saciants, i la ghrelina, inductora de l'apetit. En estudis amb antagonistes hem observat que de manera aguda l'administració de GSPE augmenta la concentració plasmàtica de GLP-1, i que l'efecte saciant del GSPE i d'un dels seus compostos, l'àcid gàlic, són directament mediats pel receptor de GLP-1. En estudis de 8 dies consecutius hem observat que els efectes saciants de l'àcid gàlic no es mantenen al llarg del temps, reforçant la importància d'altres compostos de l'extracte per a mantenir un efecte continuat. En aquests estudis subcrònics, l'administració de GSPE comporta un gran descens en la síntesi de ghrelina, un fet que hem observat estretament relacionat amb l'increment de senyalització de GLP-1 a l'hipotàlem, la inducció de la sacietat i l'efecte lipolític del GSPE. Esperem aquests estudis permetin iniciar estudis per a l'aplicació del GSPE en humans.<br>Dados los problemas de salud asociados al sobrepeso, en esta tesis hemos investigado el posible uso de un extracto de proantocianidinas de pepita de uva (GSPE) como agente saciante, utilizando ratas como modelo de experimentación. Hemos observado que bajo una pauta de administración adecuada, el GSPE disminuye la ingesta tanto de manera aguda como de forma continuada, durante períodos de 8 días consecutivos. Estas propiedades saciantes, sumadas a un efecto lipolítico, resultan en un descenso significativo del peso corporal. Al investigar las vías de señalización implicadas, hemos observado que la administración de GSPE modifica la producción y secreción de varias hormonas gastrointestinales que afectan el apetito, entre las que destacan el GLP-1, de efectos saciantes, y la ghrelina , inductora del apetito. En estudios con antagonistas hemos observado que de manera aguda la administración de GSPE aumenta la concentración plasmática de GLP-1, y que el efecto saciante del GSPE y de uno de sus compuestos, el ácido gálico, son directamente mediados por el receptor de GLP-1. En estudios de 8 días consecutivos hemos observado que los efectos saciantes del ácido gálico no se mantienen a lo largo del tiempo, reforzando la importancia de otros compuestos del extracto para mantener un efecto continuado. En estos estudios subcrónicos, la administración de GSPE conlleva un gran descenso en la síntesis de ghrelina, un hecho que hemos observado estrechamente relacionado con el incremento de señalización de GLP-1 en el hipotálamo, la inducción de la saciedad y el efecto lipolítico del GSPE. Esperamos estos estudios permitan iniciar estudios para la aplicación del GSPE en humanos.<br>Given the health problems associated with overweight, in this thesis we have investigated the possible use of a grape seed proanthocyanidin extract (GSPE) as a satiating agent, using rats as an experimental model. We have observed that under an adequate administration pattern, GSPE decreases intake both acutely and continuously along periods of 8 consecutive days. These satiating properties, added to a lipolytic effect, result in a significant decrease in body weight. In investigating the signaling pathways involved, we have observed that the administration of GSPE modifies the production and secretion of several gastrointestinal hormones that affect appetite, including GLP-1, with satiating effects, and the appetite-inducing hormone ghrelin. In studies with antagonists we have observed that the administration of GSPE increases the plasma concentration of GLP-1 and that the satiating effect of GSPE and one of its compounds, gallic acid, is directly mediated by the GLP-1 receptor. In studies of 8 consecutive days we have observed that the satiating effects of gallic acid are not maintained over time, reinforcing the importance of other compounds in the extract to maintain a continued effect. In these subchronic studies, GSPE administration leads to a large decrease in ghrelin synthesis, a fact that we have observed closely related to the increase in GLP-1 signaling in the hypothalamus, the satiety induction and the lipolytic effect of GSPE . We hope these studies will allow translational studies for the application of GSPE in humans.

Las procianidinas son compuestos bioactivos presentes en frutas y vegetales. Aunque se conocen los efectos beneficiosos de estos compuestos en la homeostasis de la glucosa, su acción en la funcionalidad de la célula β no es clara. La presente tesis doctoral se ha centrado en describir los efectos de las procianidinas en la síntesis y secreción de insulina. Nuestros resultados muestran la capacidad de las procianidinas de modificar la funcionalidad de la célula β aumentando la relación insulina plasmática/mRNA, aunque la efectividad del tratamiento depende de la situación fisiológica. En situaciones no patológicas, las procianidinas afectan la insulinemia modificando la síntesis, secreción y/o degradación de la insulina. En situaciones de resistencia a la insulina, el tratamiento crónico con procianidinas disminuye la síntesis y secreción de insulina gracias a su acción limitando el acúmulo de lípidos. En cambio, en un modelo más dañado (obesidad genética), las procianidinas ejercen efectos similares pero no son capaces de mejorar la hipersinulinemia. En conclusión, las procianidinas, en las dosis ensayadas, pueden utilizarse únicamente como compuestos bioactivos limitando la disfuncionalidad de la célula β en sus estados iniciales.<br>Les procianidines són compostos bioactius presents en fruites i vegetals. Tot i que es coneixen els efectes beneficiosos d’aquests compostos en l’homeòstasi de la glucosa, la seva acció en la funcionalitat de la cèl•lulaβ no és clara. La present tesi doctoral s’ha centrat en descriureels efectes de les procianidines en la síntesi i secreció d’insulina. Els nostres resultats mostren la capacitat de les procianidines de modificar la funcionalitat de la cèl•lula β augmentant la relació insulina plasmàtica/mRNA, tot i que l’efectivitat del tractamentdepèn de la situaciófisiològica. En situacions no patològiques, les procianidines afecten la insulinèmia modificant la síntesi, secreciói/o degradació d’insulina. En situacions de resistència a la insulina, el tractamentcrònicamb procianidines disminueix la síntesi i secreció d’insulina gràcies a la seva acció limitant l’acumulació de lípids. En canvi, en un model més danyat (obesitat genètica), les procianidines exerceixen efectes similars però no son capaces de millorar la hiperinsulinèmia. En conclusió, les procianidines, en les dosis assajades, podenutilitzar-seúnicament coma compostos bioactiuslimitant la disfuncionalitat de la cèl•lula β en els seus estats inicials.<br>Procyanidins are bioactive compounds found in fruits and vegetables widely consumed. It has been reported that procyanidins show some beneficial effects on glucose homeostasis, although their effects on β-cell functionality remain unresolved. This doctoral thesis is focus on describing the effects of procyanidins on insulin synthesis and secretion. Our results showed that procyanidins modify β-cell functionality through increasing the plasma insulin/mRNA ratio, although the effectiveness of the treatment depends on the physiological situation. Under non-pathological situation, procyanidins affected insulinaemia by modifying insulin synthesis, secretion and/or degradation activity. Under insulin-resistance situation, chronic procyanidins administration decreased insulin synthesis and secretion, thanks to its lipid-lowering effect. Otherwise in a more damaged model, Zucker fatty rat, procyanidins treatment is not able to reduce insulin plasma levels although they repress insulin expression. In conclusion, procyanidins could be used as bioactive compound to limit β-cell dysfunctions under high-palatable diets, but at the assayed doses, it is not enough to counteract a strong metabolic disruption.

Procyanidins have been reported to modulate glucose homeostasis and β-cell functionality. However, their effects on pancreatic cell mass remain unknown. Therefore, this doctoral thesis focused on the study of the effects of a grape seed procyanidin extract (GSPE) on proliferation and apoptosis processes in pancreatic cells. Our results indicate that although the extract did not affect these processes under healthy conditions, it modulated β-cell proliferation and apoptosis under altered conditions. In vitro, GSPE enhanced the pro-apoptotic effects of high glucose and were antiproliferative under high glucose, insulin, and palmitate levels in the INS-1E cell line. In vivo, the effects of the extract depended on the dose, the duration of the treatment, and/or the gender. However, the extract tended to counteract the deleterious effects of the cafeteria diet or the Zucker Fatty genotype. Concerning the adenocarcinoma cell line MIA PaCa-2, GSPE exerted antiproliferative and pro-apoptotic effects, demonstrating anti-carcinogenic activity.<br>Les procianidines són compostos fenòlics abundants en plantes i vegetals. S’ha demostrat que aquests compostos bioactius tenen efectes beneficiosos per la salut, entre els quals destaquen les seves propietats antiinflamatòries i antioxidants. També s’ha vist que participen en l’homeòstasi dels lípids i la glucosa. En un estudi previ realitzat en el grup de recerca, es van avaluar els efectes d’un extracte de procianidines de pinyol de raïm (GSPE) en un model de resistència a la insulina induït per l’alimentació de rates femelles amb una dieta de cafeteria. Es va veure que el GSPE reduïa l’índex HOMA-IR i els nivells d’insulina plasmàtica, suggerint una millora de la resistència a la insulina en teixits perifèrics. A més a més, aquests resultats semblaven indicar que les procianidines podrien estar afectant el pàncrees, el principal òrgan responsable de l’homeòstasi dels nutrients, ja sigui millorant la funcionalitat o la massa de les cèl•lules β pancreàtiques. De fet, en una tesi doctoral duta a terme en paral•lel amb una altra, en la qual es va concloure que les procianidines actuen en el pàncrees modulant la síntesi, secreció i degradació de la insulina. Els individus amb diabetis del tipus 2 presenten hiperglucèmia i un metabolisme lipídic alterat, juntament amb resistència a la insulina, disfunció de les cèl•lules β i disminució de la massa β. Tot i que determinats factors genètics hi estan implicats, la diabetis del tipus 2 està estretament lligada a l’obesitat, i ambdós patologies estan assolint proporcions d’epidèmia a nivell mundial. En els primers estadis de la resistència a la insulina, la massa β s’incrementa per compensar la hiperglucèmia. Tot i així, quan les cèl•lules β ja no són capaces de compensar l’augment de la demanda d’insulina, la massa β es veu reduïda degut a un augment de l’apoptosi. A més a més, considerant el pàncrees, l’adenocarcinoma pancreàtic és un dels càncers més agressius, caracteritzat per una elevada resistència al tractament. L’acumulació d’alteracions genètiques resulta en un augment del creixement cel•lular i de la proliferació i en una inhibició de l’apoptosi. D’aquesta manera, l’obtenció d’informació sobre els compostos naturals amb efectes beneficiosos sobre la proliferació i l’apoptosi en les cèl•lules pancreàtiques, processos estretament lligats i alterats en les malalties mencionades anteriorment, és de gran interès. Els efectes de les procianidines sobre la proliferació i l’apoptosi han estat molt estudiats en diferents tipus cel•lulars. En línies cel•lulars de càncer les procianidines baixen els nivells de proliferació i incrementen l’apoptosi, actuant com a anticarcinogèniques. En altres tipus cel•lulars, les procianidines actuen com a eina terapèutica, protegint les cèl•lules del dany induït per factors ambientals o químics, disminuint l’apoptosi i estimulant el creixement cel•lular. Tot i així, existeix poca informació relativa als efectes de les procianidines en el pàncrees. Per tant, aquesta tesi doctoral es va centrar en l’estudi dels efectes de les procianidines sobre la proliferació i l’apoptosi de les cèl•lules pancreàtiques, avaluant la modulació d’aquests processos en situacions fisiològiques o patològiques. Per assolir els nostres objectius, vam utilitzar models in vivo de rates sanes, de rates amb obesitat induïda per la dieta i rates amb obesitat induïda genèticament; i models in vitro, usant la línia cel•lular d’insulinoma de rata INS-1E i d’adenocarcinoma de pàncrees MIA PaCa-2. La hiperglucèmia postprandial i la dislipèmia són factors comuns que tenen lloc prèviament al desenvolupament de la diabetis del tipus 2. L’exposició crònica a un ambient hiperglucèmic i a elevades concentracions d’àcids grassos causa la disfunció de les cèl•lules β pancreàtiques i la mort cel•lular, fenòmens anomenats glucotoxicitat i lipotoxicitat, respectivament. D’aquesta manera, quan vam exposar les cèl•lules INS-1E a elevades concentracions de glucosa i palmitat, ambdós nutrients van incrementar l’apoptosi. Quan, en aquestes condicions, les cèl•lules es van tractar amb GSPE, l’extracte va incrementar els efectes pro-apoptòtics de l’elevada glucosa, sense modificar la situació de lipotoxicitat. L’apoptosi induïda pel GSPE en situacions d’hiperglucèmia involucra la via intrínseca de l’apoptosi. In vivo, vam continuar l’estudi previ realitzat en rates femelles amb obesitat induïda per una dieta de cafeteria realitzat, i vam veure que GSPE modulava els marcadors d’apoptosi en el pàncrees d’aquestes rates, però els efectes eren dependents de la dosi i el període de tractament. Tot i així, el tractament semblava que tendia a contrarestar l’augment de l’apoptosi de les rates alimentades amb dieta de cafeteria. En canvi, quan els efectes de l’extracte es van analitzar en rates mascle, GSPE incrementava un marcador pro-apoptòtic, suggerint un increment de l’apoptosi en les rates tractades amb l’extracte. D’aquesta manera, es conclou que la modulació dels marcadors d’apoptosi per part del GSPE en rates alimentades amb dieta de cafeteria és dependent de la dosi, el període de tractament i/o el gènere. Pel que fa als efectes de GSPE sobre la proliferació, quan les cèl•lules β pancreàtiques es van exposar a elevats nivells de glucosa i insulina, els quals indueixen la proliferació, i nivells alts de palmitat, el qual inhibeix la proliferació, l’extracte va mostrar un clar efecte antiproliferatiu. Aquests efectes antiproliferatius són probablement a causa de les molècules d’alt pes molecular, les quals no es poden absorbir a l’intestí, de manera que cal tenir-ho en compte en el moment de comparar els efectes obtinguts in vitro amb els possibles efectes in vivo. De fet, en els experiments de rates alimentades amb una dieta de cafeteria, el GSPE no va modificar els marcadors de proliferació analitzats. Com a model d’obesitat induïda genèticament, es van utilitzar rates Zucker Fatty. Quan aquestes rates es van tractar crònicament amb GSPE, tot i que l’extracte contrarestava l’expressió de marcadors d’apoptosi i proliferació en comparació amb les rates obeses no tractades, els canvis moleculars induïts per les procianidines no van ser suficients per contrarestar l’efecte genètic de les rates Zucker Fatty a un nivell fisiològic, ja que tant l’apoptosi com els nivells plasmàtics de glucosa i insulina eren tan elevats com en les rates control. En aquest experiment, també es va analitzar el perfil proteic dels illots realitzant un estudi de proteòmica. Un dels processos biològics en els quals les proteïnes modificades per GSPE estaven involucrades era l’apoptosi i la mort cel•lular. Els nivells de la majoria de les proteïnes incloses en aquest grup contrarestaven els efectes del genotip Zucker Fatty, de la mateixa manera que es va observar en els marcadors d’expressió gènica. Per tant, tenint en compte les rates Zucker Fatty com a referència d’apoptosi, el GSPE tendia a millorar aquest procés, tot i que no va induir canvis als nivells finals d’apoptosi. Un cop analitzats els efectes de GSPE en les cèl•lules β en situacions patològiques, es van avaluar els seus efectes en situacions fisiològiques. El tractament de les cèl•lules INS-1E amb GSPE no va modificar ni l’apoptosi ni la proliferació d’aquestes cèl•lules. Aquests resultats in vitro coincideixen amb els observats in vivo, en els quals, el tractament crònic de rates amb GSPE no va modificar ni l’apoptosi ni la massa β. En aquest experiment, el perfil de microRNA també es va analitzar, ja que alguns microRNA s’ha vist que poden regular la funció pancreàtica, incloent la regulació de la síntesi i la secreció de la insulina i l’apoptosi. Tot i que vam trobar que els microRNAs dels illots pancreàtics eren diana de les procianidines, els modificats per l’extracte no estan involucrats en els processos de proliferació i apoptosi, fet que confirma el fet que el GSPE no altera aquests processos en condicions fisiològiques. Finalment, una altra situació patològica en la qual la proliferació i l’apoptosi estan alterats en cèl•lules pancreàtiques és en càncer, en el qual la proliferació està incrementada i l’apoptosi inhibida. D’aquesta menera, vam analitzar els efectes del GSPE en la línia cel•lular d’adenocarcinoma pancreàtic MIA PaCa-2 i vam veure que l’extracte inhibia la proliferació cel•lular i incrementava l’apoptosi, procés mediat per la modulació de proteïnes de la família de la Bcl-2 i per la despolarització de la membrana mitocondrial, implicant la via intrínseca de l’apoptosi. En aquest cas, els components de l’extracte amb més activitat antiproliferativa i pro-apoptòtica també van ser identificats. Tant l’epigal•locatequina gal•lat com l’àcid gàl•lic foren els components amb efectes antiproliferatius més elevats, però, considerant que la concentració d’àcid gàl•lic en l’extracte és més de 40 vegades més elevat que la d’epigal•logatequina gal•lat, es va considerar l’àcid fenòlic com un dels components de l’extracte responsables dels efectes observats. De la mateixa manera que el GSPE, l’àcid gàl•lic modulava l’expressió de proteïnes de la família de la Bcl-2 i promovia la despolarització de la membrana mitocondrial. En aquest estudi, es van utilitzar dues aproximacions per tal d’apropar-nos a una situació in vivo, ja que un cop ingerides, no tots els components de les procianidines són absorbides a l’intestí. Prèviament, són hidrolitzades en l’intestí prim i metabolitzades en l’intestí prim i el fetge. A més a més, les procianidines i els metabòlits que no són absorbits en l’intestí prim, poden ser absorbits en l’intestí gros posteriorment a l’acció de la microflora bacteriana. D’aquesta manera, per una banda, vam tractar les cèl•lules amb medis basolaterals que contenien els components de l’extracte absorbits i metabolitzats pels enteròcits humans Caco-2. Aquest sistema és novedós, tot i així, les cèl•lules Caco-2 s’han usat àmpliament per estudiar l’absorció i secreció intestinal de fàrmacs i compostos de la dieta. Tot i així, els compostos absorbits i metabolitzats per les cèl•lules Caco-2 no van modificar la taxa de proliferació de les cèl•lules MIA PaCa-2. De fet, l’anàlisi dels medis basolaterals va revelar que ni l’epigal•locatequina gal•lat ni l’àcid gàl•lic, les molècules més efectives en la inhibició de la proliferació, no eren absorbits per les cèl•lules Caco-2. Per altra banda, també vam tractar les cèl•lules MIA PaCa-2 amb sèrums de rata tractats amb GSPE. Aquesta aproximació, que segons el nostre coneixement no s’havia usat anteriorment, permet l’exposició de les cèl•lules als compostos fenòlics absorbits i metabolitzats en l’organisme i que aconsegueixen arribar al teixit diana in vivo. Tot i que lleument, el tractament amb els sèrum de les rates tractades amb GSPE van inhibir la proliferació de les cèl•lules d’adenocarcinoma de pàncrees. Per concloure, en aquesta tesi doctoral hem vist que el GSPE modula la proliferació i l’apoptosi de les cèl•lules pancreàtiques, tant in vitro com in vivo, però els seus efectes són dependents del model, la dosi i la durada del tractament. Hem utilitzat tècniques òmiques i diferents aproximacions in vitro per tal d’acostar-nos a situacions in vivo, a més d’identificar les molècules de l’extracte responsables dels efectes observats.

Prolonged exposure to high ambient temperature without cooling causes heat stress (HS) resulting in altered growth, body composition and metabolic dysfunction in pigs. Grape seed extract (GSE) has been shown to reduce inflammation, and improve glucose transport and metabolism. Thus, GSE may be an effective supplement to combat the consequences of heat stress; however this possibility has not been evaluated in a large animal model. The objective of the current study was to examine the effect of GSE supplementation on pig performance and body composition during HS. Twenty-four female pigs (62.3± 8 kg BW) were randomly assigned to a 2X2 factorial experiment; thermal neutral (TN; 21-22°C) or heat stress conditions (HS; 33-34°C) for 7 days and fed either a control or a GSE supplemented diet (12mg/kg body weight). Body temperature (TB), respiration rate (RR) and feed intake (FI) were measured daily. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Respiration rate and TB increased in the HS control group compared to the TN control group (p<0.05), however GSE did not alter these parameters compared to control for the duration of the 7 day period. HS decreased FI (P < 0.05). Fasting blood glucose concentrations were approximately 1.5-fold greater in the control diet compared to their GSE supplemented counterpart (p=0.067) on day 6 of the HS period, but did not differ between groups at the end of day 7 of HS. Body composition analysis indicated bone mineral density, bone mineral content, and percent change of fat remain unchanged between treatment groups. Percent change in weight was significantly reduced in HS. Lean tissue accretion was 45% greater in TN compared to HS groups (p<0.05). Endotoxin concentrations were approximately 2-fold lower in the HS-GSE group compared to the control (P=0.083). Grape seed extract supplementation does not appear to alter pig growth performance or body composition, but does appear to delay the onset of reduced feed intake by 1 day, reduce intestinal permeability, and improve insulin sensitivity during additional stress.<br>Master of Science in Life Sciences

Thesis (MSc)--Stellenbosch University, 2013.<br>ENGLISH ABSTRACT: Contusion injuries cause significant muscle damage, activating a series of cellular events. Satellite cells (SC), the key role players in muscle regeneration, are activated to proliferate and develop into mature myoblasts, which could fuse to form new myotubes or to repair damaged fibres. Evidence suggests that anti-oxidants, such as those found in grape seed extract (GSE), enhance repair, but their effect on SCs is still unclear. This study aimed to harvest and culture primary rat myoblasts to investigate the effect of chronic in vivo GSE supplementation on SCs following a standardised crush injury. Using a modified pre-plate technique, myoblasts were harvested from rat muscle and then compared with the immortal C2C12 cell line for proliferation and differentiation competence. Several media options were compared: i) DMEM with or without L-glutamine, ii) Ham‘s F10 or iii) DMEM with L-glutamine and Ham‘s F10 combined. Primary myoblasts proliferated and differentiated at a much slower rate than C2C12 cells. The combined media was selected for further use. To investigate the effects of GSE on the recovery, rats were supplemented daily with GSE or placebo 14 days prior to a standardised mass-drop crush injury to the gastrocnemius. SCs were isolated and cultured from uninjured (NI, baseline) and from injured rats 4 hours (4h), 3 days (3d) or 14 days (14d) post-injury. Expression of myogenic proteins Pax7, M-cadherin, MyoD, CD56, desmin and CD34 was determined by flow cytometry. Myoblasts were sorted according to their CD56 and CD34 expression and three sub-sets were collected and re-cultured, namely CD56+/CD34-, CD56-/CD34+ and CD56+/CD34+. After 24 hours, sorted cells were stained for desmin expression. Pax7, M-cadherin and MyoD were present in 100% of isolated cells from all groups confirming their myogenic SC identity. For all groups, desmin was expressed only in ~80% of SCs. Lower adhesion competency in GSE supplemented groups resulted in lower yield obtained for culturing. Expression of CD56 increased significantly 3d post-injury in the placebo group. In contrast, with GSE, CD56 already increased 4h post-injury and decreased again 3d post-injury. Although CD34 expression did not differ dramatically, expression pattern resembled that of CD56. Immunocytochemistry revealed a range in morphology and desmin expression of sorted myoblasts. More myoblasts with high desmin expression were observed in the two CD56+ sub-sets (irrespective of CD34 expression), indicating that CD56 is still expressed in more mature myoblasts. Flow cytometry revealed a population of myoblasts expressing particularly high levels of desmin, primarily in the non-injured baseline GSE group. We hypothesise that this result is an indication of preparedness of myoblasts to respond earlier to injury, enabling quicker repair. This cell population with high desmin content is restored in skeletal muscle after repair (14d), only when supplemented with GSE. In conclusion, GSE attenuated adhesion competence of primary myoblasts in culture, but resulted in earlier maturation of SCs, possibly due to baseline preparedness of myoblasts in uninjured muscle for a quick response. Both reduced adhesion competence and early progression of myoblasts could enhance wound healing in skeletal muscle.<br>AFRIKAANSE OPSOMMING: Kneuswonde veroorsaak aansienlike skade aan skeletspier, wat ‘n reeks sellulêre prosesse in werking stel. Satellietselle, die hoofrolspelers tydens spierregenerasie, vermenigvuldig en ontwikkel tot volwasse mioblaste, wat saamsmelt om nuwe spiervesels te vorm. Antioksidante, soos die wat in druiwepit-ekstrak voorkom, bespoedig herstel, maar hul uitwerking op satellietselle is steeds onduidelik. Die doel van hierdie studie was om mioblaste uit rotspiere te isoleer en te kweek om die effek van langdurige in vivo aanvulling van druiwepit-ekstrak op satellietselle na ‘n kneusbesering te bepaal. 'n Aangepaste protokol is gebruik om primêre mioblaste te isoleer, wat daarna met C2C12 selle, ten opsigte van hul vermenigvuldigings- en differensiasievermoë vergelyk is. Verskeie groeimedia is gebruik: i) DMEM met of sonder L-glutamien, ii) Ham F10 en iii) ‘n kombinasie van DMEM, L-glutamien en Ham F10. Primêre mioblaste het stadiger vermenigvuldig en gedifferensieer as C2C12 selle. Die gekombineerde medium is vir verdere gebruik gekies. Om die uitwerking van druiwepit-ekstrak op spierherstel te ondersoek, is rotte vir 14 dae onderwerp aan daaglikse aanvullings van druiwepit-ekstrak of placebo voor ‘n gestandardiseerde kneusbesering aan die gastrocnemius. Satellietselle is geïsoleer vanuit onbeseerde spier (basiskontrole) en vanuit beseerde spier 4 ure (4h), 3 dae (3d) en 14 dae (14d) na die besering. Die uitdrukking van spierverwante proteïene Pax7, M-cadherin, MyoD, CD56, desmin en CD34 is vasgestel met 'n vloeisitometer. Mioblaste is daarna gesorteer op grond van hul CD56- en CD34-uitdrukking. Drie sub-groepe is versamel en verder gekweek, nl. CD56+/CD34-, CD56-/CD34+ en CD56+/CD34+. Na 24 uur is gesorteerde selle gekleur om desmin-uitdrukking te bepaal. Pax7, M-cadherin en MyoD is deur 100% satellietselle in alle groepe uitgedruk, wat hul spierverwante identiteit bevestig, alhoewel slegs 80% selle in alle groepe desmin uitgedruk. Druiwepit-ekstrak het die vermoë van selle om aan plate te heg onderdruk, wat gelei het tot ‘n laer opbrengs van mioblaste. Drie dae na die besering in die placebo groep het die CD56-uitdrukking beduidend toegeneem. In teenstelling hiermee het CD56-uitdrukking in die druiwepit-ekstrak groep 4 ure na die besering beduidend toegeneem en weer afgeneem na 3 dae. Hoewel daar nie sulke dramatiese verskille was tussen groepe ten opsigte van CD34-uitdrukking nie, was daar ‘n soortgelyke tendens as vir CD56-uitdrukking. Immunositochemie het ‘n verskeidenheid van morfologieë en variërende desminvlakke in gesorteerde mioblaste blootgestel. In die twee CD56+ groepe is meer mioblaste wat hoë desmin vlakke uitdruk gevind, wat aandui dat CD56 uitgedruk word deur meer volwasse mioblaste, ongeag van CD34-uitdrukking. Tydens vloeisitometrie is ‘n populasie selle wat hoë desminvlakke uitdruk, hoofsaaklik in die onbeseerde en 14d druiwepit-ekstrak groepe gevind. Dit is ‘n aanduiding dat sommige mioblaste voorbereid is om na 'n besering vinniger te reageer. Na die herstelproses word hierdie groep selle hernu in die teenwoordigheid van druiwepit-ekstrak-aanvulling. Die resultate het gevolglik daartoe gelei dat druiwepit-ekstrak die hegtingsvemoë van mioblaste verlaag, maar dat die aanvulling in vivo tot vroeër ontwikkeling van mioblaste lei, waarskynlik deur satellietselle voor te berei vir 'n vinnige respons na ‘n besering. Beide die onderdrukking van aanhegting aan kultuurplate en die vroeë ontwikkeling van mioblaste, kan die herstel van die skeletspier verbeter.<br>NRF and the Harry Crossley bursary for funding

Corynebacterium diphtheriae, Pseudomonas aeruginosa, Ricinus communis, Shigella dysentariae, and Vibrio cholerae produce AB toxins which share the same basic structural characteristics: a catalytic A subunit attached to a cell-binding B subunit. All AB toxins have cytosolic targets despite an initial extracellular location. AB toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against these toxins are therefore hard to develop because they use different surface receptors, entry mechanisms, enzyme activities, and cytosolic targets. We have found that grape seed extract provides resistance to five different AB toxins: diphtheria toxin (DT), P. aeruginosa exotoxin A (ETA), ricin, Shiga toxin, and cholera toxin (CT). To identify individual compounds in grape seed extract that are capable of inhibiting the activities of these AB toxins, we screened twenty common phenolic compounds of grape seed extract for anti-toxin properties. Three compounds inhibited DT, four inhibited ETA, one inhibited ricin, and twelve inhibited CT. Additional studies were performed to determine the mechanism of inhibition against CT. Two compounds inhibited CT binding to the cell surface and even stripped bound CT off the plasma membrane of a target cell. Two other compounds inhibited the enzymatic activity of CT. We have thus identified individual toxin inhibitors from grape seed extract and some of their mechanisms of inhibition against CT. This work will help to formulate a defined mixture of phenolic compounds that could potentially be used as a therapeutic against a broad range of AB toxins.<br>M.S.<br>Masters<br>Molecular Biology and Microbiology<br>Medicine<br>Biotechnology

Gliomas are rare intrinsic brain tumours which account for 2% of all cancers. Glioblastoma multiforme is the most malignant malignant glioma form and remains incurable. The biological features which preclude successful therapy include heterogeneity, diffuse invasive patterns and angiogenesis. Despite, advances in current conventional treatments the median survival time is only 14 months. Hence there is a need to investigate novel therapeutic approaches which can be included alongside conventional treatment. One such approach is the use of micronutrients in the management of glioblastoma multiforme. This study evaluated the affects of two micronutrient extracts, red clover extract (RCE) and red grape seed extract (RGSE), on human adult malignant brain tumours in vitro. Four primary (or short-term) cell cultures derived from human brain tumour biopsies, an established cell line and normal human brain cells from an epileptic pateint were used to measure the cell viability, anti-invasive, anti-angiogenic and pro-apoptotic potentials, following 48-hour treatment with the IC50s of either micronutrient extract. Both RCE and RGSE exhibited similar affects on the glioma cell cultures. They both appeared to reduce cell viability, invasive potential and angiogenesis potential though did not appear to have any significant affect on the apoptotic portential of the glioma cultures. For example, incubation with 0.007-1ug/ml RCE caused a significant (p < 0.05) reduction of in viability of glioma cells but did not affect viability of normal astrocytes. Similar results were obtained for RGSE. These doses also resulted in a significant decrease in invasion and angiogenesis (p<0.05). Effects varied between cell lines but in general decreased by 50-60%. This suggests that both RCE and RGSE do affect the development of glioma cell cultures in vitro and warrant further study into the pathways in which this may occur.

Grape Seed Extract (GSE) has received acceptance almost globally as an ingredient for human consumption. It is one of the more widely used botanical extracts, due to increasing scientific findings supporting health benefits. However, it remains a specialty item relative to global commodities. In the United States, GSE has ranked among the top 20 best-selling dietary supplements in the Food, Drug and Mass Market channel. The motivation behind purposeful adulteration in commercial products is financial gain (also known as economically motivated adulteration) and to increase the concentration in proanthocyanidins (PACs) as primary marker compounds as a means to contribute to the misperception of quality. Adulterants include other PAC-rich materials, which are available at lower cost. Thus, a bulk distributor of GSE or another manufacturer along the value chain can take advantage of the chemical similarity between GSE and peanut skin extract since the spectrophotometric assays typically used in industry are not specific enough to discriminate between grape seed PACs and PACs from other plant extracts. Due to reliance on non-specific proximate assays across the value-chain, adulteration can go undetected downstream in the commodity chain, such as those involved in distribution, packaging, wholesale, and retail sales. This laboratory guidance document presents a review of the various analytical technologies and methods used to differentiate between grape seed extracts and potential adulterants.

Food is an essential to our existence but under certain conditions it could become the origin to the accumulative health damages. Technological processes as heating, chopping, mincing, grounding, promote the lipid oxidation process in muscle tissues and meat foodstuffs. Lipid oxidation occurred rapidly in turkey muscle, intermediate in duck, and slowest in chicken during frozen storage. Depletion of tocopherol during frozen storage was more rapid in turkey and duck compared to chicken. These processes developed from lipid peroxides produce many cytotoxic compounds including malondialdehyde (MDA). The muscle tissue is further oxidized in stomach conditions producing additional cytotoxic compounds. Oxidized lipids that are formed during digestion of a meal possess the potential to promote reactions that incur vascular diseases. A grape seed extract (1% of the meat weight) and butylated hydroxytoluene (0.2% of the lipid weight) were each effective at preventing formation of lipid oxidation products for 3 hours during co-incubation with cooked turkey meat in simulated gastric fluid (SGF). Polyphenols in the human diet, as an integral part of the meal prevent the generation and absorption of cytotoxic compounds and the destruction of essential nutrients, eg. antioxidants vitamins during the meal. Polyphenols act as antioxidants in the gastrointestinal tract; they scavenge free radicals and may interact with reactive carbonyls, enzymes and proteins. These all reactions results in decreasing the absorption of reactive carbonyls and possible other cytotoxic compounds into the plasma. Consumptions of diet high in fat and red meat are contributory risk factors partly due to an increase production of cytotoxic oxidized lipid products eg. MDA. However, the simultaneously consumption of polyphenols rich foods reduce these factors. Locating the biological site of action of polyphenols in the in the gastrointestinal tract may explain the paradox between the protective effect of a highly polyphenols rich diet and the low bioavailability of these molecules in human plasma. It may also explain the "French paradox" and the beneficial effect of Mediterranean and Japanese diets, in which food products with high antioxidants content such as polyphenols are consumed during the meal.