Добірка наукової літератури з теми "Dodonaea viscosa"

Dodonaea viscosa is a medicinal plant which has been used to treat various diseases in humans. However, the anti-insect activity of extracts from D. viscosa has not been evaluated. Here, we found that the total saponins from D. viscosa (TSDV) had strong antifeedant and growth inhibition activities against 4th-instar larvae of Spodoptera litura. The median antifeeding concentration (AFC50) value of TSDV on larvae was 1621.81 μg/mL. TSDV affected the detoxification enzyme system of the larvae and also exerted antifeedant activity possibly through targeting the γ-aminobutyric acid (GABA) system. The AFC50 concentration, the carboxylesterase activity, glutathione S-transferases activity, and cytochrome P450 content increased to 258%, 205%, and 215%, respectively, and likewise the glutamate decarboxylase activity and GABA content to 195% and 230%, respectively, in larvae which fed on TSDV. However, D. viscosa saponin A (DVSA) showed better antifeedant activity and growth inhibition activity in larvae, compared to TSDV. DVSA also exerted their antifeedant activity possibly through targeting the GABA system and subsequently affected the detoxification enzyme system. Further, DVSA directly affected the medial sensillum and the lateral sensillum of the 4th-instar larvae. Stimulation of Spodoptera litura. with DVSA elicited clear, consistent, and robust excitatory responses in a single taste cell.

Members of Dodonaea are broadly distributed across subtropical and tropical areas of southwest and southern China. This host provides multiple substrates that can be richly colonized by numerous undescribed fungal species. There is a severe lack of microfungal studies on Dodonaea in China, and consequently, the diversity, phylogeny and taxonomy of these microorganisms are all largely unknown. This paper presents two new genera and four new species in three orders of Dothideomycetes gathered from dead twigs of Dodonaea viscosa in Honghe, China. All new collections were made within a selected area in Honghe from a single Dodonaea sp. This suggests high fungal diversity in the region and the existence of numerous species awaiting discovery. Multiple gene sequences (non-translated loci and protein-coding regions) were analysed with maximum likelihood and Bayesian analyses. Results from the phylogenetic analyses supported placing Haniomyces dodonaeae gen. et sp. in the Teratosphaeriaceae family. Analysis of Rhytidhysteron sequences resulted in Rhytidhysteron hongheense sp. nov., while analysed Lophiostomataceae sequences revealed Lophiomurispora hongheensis gen. et sp. nov. Finally, phylogeny based on a combined dataset of pyrenochaeta-like sequences demonstrates strong statistical support for placing Quixadomyceshongheensis sp. nov. in Parapyrenochaetaceae. Morphological and updated phylogenetic circumscriptions of the new discoveries are also discussed.

Two new clerodane diterpenes 4 and 3, along with four known constituents, including neocleroda- 3,13-diene-15,16-olide-18-oic acid (1), stictic acid (2), hautriwaic acid (5), and 15,16-epoxy-19- hydroxy-1,3,13(16),14-clerodatetraen-18-oic acid (6), were isolated from stems and leaves of Dodonaea viscosa. Their structures were elucidated by spectroscopic methods, including one- and twodimensional NMR experiments (COSY, HMBC, HMQC, and ROESY)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A gradual increase of the areas abandoned for the farming one is occurring. These areas are occupied for a arboreal vegetation with a strong presence of pioneers species. This study was accomplished in the city of Encruzilhada do Sul, in abandoned areas that present forestry communities in initial to medium training of regeneration, with predominance of Dodonaea viscosa Jacq. on vegetation. The purpose was to characterize these natural populations, aiming at to supply subsidies to the forestry management of Dodonaea viscosa Jacq. For this, it was accomplished the floristic and structural analysis of the population, as well as, some parameters like heating value and macronutrients of wood. To the structural analysis 52 sub-parcels were installed and to the study of heating value, specific mass and constituents of wood 13 trees were cut down, of which disks were collected. The fragment is composed for a small number of species based basically in species of pioneering habit, without indications of the forest to be converging to a more advanced sucessional training. The species presents a high energetic production, with raised carbon text in the wood, what it leads to the use of the forest in the payment for environmental services. The nutrients present in the wood indicate that the exploration of the species can have consequences in mid-term and long-term, having to be considered in the planning of the activities.
Está ocorrendo um gradual aumento das áreas abandonadas pela agropecuária. Estas são ocupadas por uma vegetação arbórea com forte presença de espécies pioneiras. O estudo foi realizado no município de Encruzilhada do Sul, em áreas abandonadas que apresentem comunidades florestais em estágio inicial a médio de regeneração, com predomínio da Dodonaea viscosa Jacq. na vegetação. O objetivo foi caracterizar estas populações naturais, visando fornecer subsídio ao manejo florestal da Dodonaea viscosa Jacq. Para isso, foi realizada a análise florística e estrutural do povoamento, assim como, determinado parâmetros como poder calorífico e macronutrientes da madeira. Para análise da estrutura foram instaladas 52 sub-parcelas e para o estudo do poder calorífico, massa específica e constituintes da madeira foram abatidas 13 árvores, das quais foram coletados discos. O fragmento é composto por um pequeno número de espécies, baseados basicamente em espécies de habito pioneiro, sem indício de a floresta estar convergindo para um estágio sucessional mais avançado. A espécie apresenta uma alta produção energética, com elevado teor de carbono na madeira, o que remete ao uso da floresta no pagamento por serviços ambientais. Os nutrientes presentes na madeira indicam que a exploração da espécie pode ter consequencias no médio e longo prazo, devendo ser considerado no planejamento das atividades.

Thesis (MSc)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: In traditional medicine, there is a long-standing culture of combining herbal drugs to increase the therapeutic efficacy. The improved medical action is thought to be due to synergistic interactions between different plant bioactive components. The aim of this study was to test the pharmacological interactions in a medicinal plant combination which consisted of Agathosma crenulata, Dodonaea viscosa and Eucalyptus globulus. The rationale for the analysis of this particular mixture is that it had noteworthy antibacterial activity and exhibited the highest activity out of seven medicinal plant mixtures previously investigated. Using chromatographic analysis, the phytochemistry of the plants was also assessed. The chloroform: methanol (1:1; v/v) extracts or hydo-distilled essential oils (A. crenulata and E. globulus) were screened individually and in combinations (double and triple plant combination) for activity against five respiratory pathogens using a microdilution assay. The antimicrobial interactions in combinations were assessed with the fractional inhibitory concentration (FIC) and the isobolograms. The organic extracts generally showed the highest antimicrobial activity with E. globulus having the highest activity with MIC values below 1 mg ml-1 representing noteworthy activity. The overall activity of the aqueous extracts was poor. The essential oil activity of E. globulus was mostly noteworthy (0.5 to 2 mg ml-1) while A. crenulata essential oil displayed moderate activity (1 to 4 mg ml-1). The ΣFIC values for double combinations (1:1) of A. crenulata with D. viscosa, A. crenulata with E. globulus and D. viscosa with E. globulus were calculated from the minimum inhibitory concentration (MIC) data and the interactions were classified as synergistic, additive, indifferent and antagonistic. The highest synergistic interactions observed were for a 1:1 combination of A. crenulata with E. globulus against K. pneumoniae, S. aureus and B. subtilis with ΣFIC values of 0.07. There was only one incident of antagonism noted in the study for D. viscosa with E. globulus (1:1) against C. neoformans with ΣFIC value of 4.25. The double combinations against selective pathogens (K. pneumoniae, S. aureus and E. coli) were further analysed for interactions using isobolograms. Mostly, the antimicrobial interactions as presented by the isobolograms were congruent with FIC results which further validated the occurrence of relevant antimicrobial interactions in those combinations. The ΣFIC values for triple combinations (1:1:1) revealed mostly synergistic interactions. When the triple combinations were analysed further against certain pathogens based on the predictions of the Design of Experiments software program (MODDE 9.1®), the MIC values remained the same despite the different combinations that were tested Thin layer chromatography (TLC) was used for a quick chemical fingerprinting of the plant extracts. This was followed by a bio-autographic assay. The chemical profiles of the organic extracts and essential oils from two of the study aromatic plants (A. crenulata and E. globulus) were further analysed with liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS) respectively. For combined plant extracts, a multivariate data analysis using principal component analysis (PCA) and hierarchical clustering analysis (HCA) was used to determine the relationship of the chemical make-up of combinations with that of individual plant extracts. According to the TLC analysis, E. globulus extracts had more compounds than the other two plants in the study. For the bio-autographic assay, E. globulus and combinations that included this plant showed greater inhibition zones than A. crenulata and D. viscosa. For the LC-MS analysis, PCA and HCA showed a close relationship between A. crenulata with D. viscosa, D. viscosa with E. globulus and the triple combination. Twenty one components were identified in the essential oil of A. crenulata representing 88.83% of the total oil composition. The oil was dominated by oxygen-containing monoterpenes (46.25%). In the essential oil of E. globulus, twenty six compounds were identified making up to 95.62% of the oil composition. Oxygen-containing monoterpenes (32.98%) also dominated the E. globulus essential oil. There was no great variation in essential oil metabolites of the individual plants and their combination as shown by both PCA and HCA. The enhanced in vitro antimicrobial activity and pharmacological interactions (synergy and additivity) in some of the combinations (double and triple) that were tested in this study adds scientific support to the use of medicinal plant combinations in Western Cape traditional medicine. The metabolic profiles of plants in combination might be unique due to interaction of the different plant bioactive molecules and thus result into defined antimicrobial activity.
AFRIKAANSE OPSOMMING: In tradisionele geneeskunde is dit ’n lank bestaande kultuur om kruiemiddels te kombineer om die terapeutiese werking daarvan te verhoog. Dié verbeterde mediese werking word toegeskryf aan die oënskynlik sinergistiese interaksies tussen verskillende bioaktiewe plantkomponente. Die doel van hierdie studie was om die farmakologiese interaksies in medisinale plantkombinasies van Agathosma crenulata, Dodonaea viscosa en Eucalyptus globulus te bestudeer. Daar is op die ontleding van hierdie spesifieke mengsel besluit omdat dit oor beduidende antibakteriese waarde beskik en omdat dit uit sewe medisinale plantmengsels wat voorheen bestudeer is, as die doeltreffendste een aangewys is. Die fitochemie van die plante is ook met behulp van chromatografiese ontleding beoordeel. Deur middel van ’n mikroverdunningstoets is die chloroform:metanol- (1:1; v/v-)ekstrakte of hidrogedistilleerde vlugtige olies (A. crenulata en E. globulus) individueel sowel as in kombinasie (dubbele en drievoudige plantkombinasies) nagegaan vir hul werking met betrekking tot vyf respiratoriese patogene. Die gekombineerde antimikrobiese interaksies is met behulp van fraksioneel stremmende konsentrasie (FIC) en isobologramme ondersoek. Die organiese ekstrakte het oor die algemeen die meeste antimikrobiese aktiwiteit by E. globulus getoon, met MIC-waardes onder 1 mg ml-1 wat as noemenswaardige aktiwiteit beskou is. Die algehele aktiwiteit van die waterekstrakte was swak. Die vlugtige-olieaktiwiteit van E. globulus was merendeels noemenswaardig (0,5 tot 2 mg ml-1), terwyl die vlugtige olie van A. crenulata matige aktiwiteit getoon het (1 tot 4 mg ml-1). Die ΣFIC-waardes vir dubbelkombinasies (1:1) van A. crenulata en D. viscosa, A. crenulata en E. globulus, en D. viscosa en E. globulus is uit die minimum stremmende konsentrasie (MIC) bereken en die interaksies is as sinergisties, additief, neutraal en antagonisties geklassifiseer. Die sterkste sinergistiese interaksies is by ’n 1:1-kombinasie van A. crenulata en E. globulus met betrekking tot K. pneumoniae, S. aureus en B. subtilis opgemerk, met ΣFIC-waardes van 0,07. Die studie het slegs een geval van antagonisme opgelewer, naamlik by D. viscosa en E. globulus (1:1) met betrekking tot C. neoformans, wat ’n ΣFIC-waarde van 4,25 geregistreer het. Die werking van die dubbelkombinasies met betrekking tot gekose patogene (K. pneumoniae, S. aureus en E. coli) is voorts met behulp van isobologramme vir interaksies nagegaan. Die antimikrobiese interaksies wat uit die isobologramme geblyk het, was meestal in pas met FIC-resultate, wat die bestaan van tersaaklike antimikrobiese interaksies in daardie kombinasies verder bevestig het. Die ΣFIC-waardes vir die drievoudige kombinasies (1:1:1) het meestal sinergistiese interaksies aan die lig gebring. Toe die drievoudige kombinasies verder op grond van die voorspellings van die sagteware Design of Experiments (MODDE 9.1®) met betrekking tot sekere patogene ontleed is, het die MIC-waardes onveranderd gebly, ondanks verskillende toetskombinasies. Dunlaagchromatografie (TLC) is vir ’n vinnige chemiese ontleding van die plantekstrakte gebruik en is gevolg deur ’n bio-outografiese toets. Die chemiese profiele van die organiese ekstrakte en vlugtige olies van twee van die aromatiese plante in die studie (A. crenulata en E. globulus) is verder met vloeistofchromatografie-massaspektrometrie (LC-MS) en gaschromatografie-massaspektrometrie (GC-MS) onderskeidelik ontleed. Vir gekombineerde plantekstrakte is veelveranderlike-ontleding in die vorm van hoofkomponentontleding (PCA) en hiërargiese groepsontleding (HCA) gebruik om die verhouding van die chemiese samestelling van kombinasies in vergelyking met dié van individuele plantekstrakte te bepaal. Volgens die TLC-ontleding beskik E. globulus-ekstrakte oor meer verbindings as die ander twee plante in die studie. Vir die bio-outografiese toets het E. globulus en kombinasies daarmee groter stremmingsones as A. crenulata en D. viscosa getoon. In die LC-MS-ontleding het PCA en HCA op ’n hegte verhouding tussen A. crenulata en D. viscosa, D. viscosa en E. globulus, en die drievoudige kombinasie daarvan gedui. Een-en-twintig komponente is in die vlugtige olie van A. crenulata gevind, wat 88,83% van die algehele oliesamestelling uitmaak. Die olie is deur suurstofhoudende monoterpene (46,25%) oorheers. Die vlugtige olie van E. globulus het 26 verbindings opgelewer, wat 95,62% van die oliesamestelling uitmaak. Suurstofhoudende monoterpene (32,98%) het ook die vlugtige olie van E. globulus oorheers. Nóg PCA nóg HCA het op enige beduidende variasie in die metaboliete van die vlugtige olies van die individuele plante en hul kombinasies gedui. Die verhoogde in vitro- antimikrobiese aktiwiteit en farmakologiese interaksies (sinergie en additiwiteit) in van die kombinasies (dubbel én drievoudig) wat in hierdie studie getoets is, bied wetenskaplike stawing vir die gebruik van medisinale plantkombinasies in Wes-Kaapse tradisionele geneeskunde. Die metaboliese profiele van plantkombinasies kan verander weens die interaksie van die verskillende bioaktiewe plantmolekules, en kan baie bepaalde antimikrobiese aktiwiteit tot gevolg hê.

Las hojas de Dodonaea viscosa Jacq presenta propiedades antinflamatorias, información etnofarmacológica, el cual fue obtenida en la provincia de Aymaraes, departamento de Apurimac, Perú. La presente investigación evalúa el efecto anticancerígeno del extracto hidroalcohólico de hojas de Dodonaea viscosa Jacq en el cáncer colorrectal y el efecto citotóxico en células tumorales HT-29. El material vegetal fue colectado en el distrito de Chalhuanca, provincia de Aymaraes, departamento de Apurimac a 2.888 m.s.n.m. Las hojas fueron seleccionadas y se procedieron a la maceración con alcohol al 70%, finalmente se obtuvo un extracto seco que se utilizó para realizar el ensayo químico cualitativo por cromatografía liquida acoplado a espectrometría de masas UHPLC/MS. Una vez determinado los componentes mayoritarios se procedió a determinar las características farmacocinéticas in silico utilizando la herramienta Swiss ADME, la citotoxidad sobre células HT-29 (adenocarcinoma colorectal) y el cáncer inducido por 1,2 dimetilhidracina empleando el extracto dosis de 50 y 200 mg/Kg. Se identificaron 57 compuestos tipo flavonoides y terpénico. En el ensayo de citotoxicidad por sulforodamina B (SRB) sobre la línea celular HT-29 resultó que la CI50 fue mayor a 20 µg/mL y en el estudio histopatológico se observó displasia y adenomas a la máxima dosis de 50 y 200 mg/Kg de extracto evaluado. Concluye que el extracto hidroalcohólico de D. viscosa contiene ácido dodonico como componente mayoritario, tiene efecto citotóxico in vitro sobre las células HT-29, pero ningún efecto de protección a nivel histopatológico en el ensayo cancer de colon inducido en ratas.

In most rural areas, reliance on traditional medicine and food is high and this is attributed to both economic and cultural factors. The edible stink-bug (Encosternum delegorgueiSpinola), local name “thongolifha” is consumed by the Venda tribe in Limpopo Province of South Africa. Thongolifha is important to the Venda tribe in terms of culture, nutrition and economical value. They eat it raw or cooked with porridge or as a snack. The edible stink-bug is sold at the Thoyandou open market and provides valuable income for the harvesters. Many insects have been reported to contain good source of proteins minerals and vitamins. In terms of medicinal value, insects have also been used in folk medicine in the past by various cultures to treat many ailments such as stroke, asthma, cold, etc. Some insects are also known to sequester compounds from their host plant and use them for its defensive mechanism. The host plant for thongolifha was identified as Dodonaea viscosa Jacq. var. angustifolia which has been reported to have antibacterial activity. The aim of this study was to investigate the possible interaction between the thongolifha and its host plant Dodonaea viscosa. Since thongolifha is so important to the Venda tribe and its nutritional value was never analysed before it was also relevant to determine its nutritional composition. Nutritional components of thongolifha such as the proteins, fats, amino acids and carbohydrates contents were detected by using standardized methods. Thongolifha contained 35.2% protein, 50.6% fat and 7.63 g/100 g carbohydrate with an energy content of 2599 kJ/100 g. These results compare well to nutritional values of other edible insects such as termites (41.8% protein and 44.3% fat) and wasps (31% protein and 62% fat).The mopane worm has higher protein content (63.5%) and a lower fat content of (18%). Mineral content of thongolifha (1.2 g/100 g) was found to be at a comparable level to other bugs such as the Acantocepphala declivis (1.0 g/100g). Analysis of essential amino acids varied from 0.82 mg/100 g (threonine) and 1.32 mg/100 g (valine). The nutritional composition of thongolifha is acceptable and thongolifha is not just a traditional delicacy but also contributes as a diet supplement of the Venda tribe. Between 680 and 3400 of thongolifha will however have to be consumed to supply the daily nutritional needs for the essential amino acids phenylalanine and methionine. Analysis for antibacterial activity of thongolifha was carried out after extracting with solvents of varying polarities, separation by thin layer chromatography (TLC) and bioautography against four nosocomial bacteria; Gram-negative; Escherichia coli and Pseudomonas aeruginosa; Gram positive; Staphylococcus aureus and Enterococcus faecalis. Bioautography results of the thongolifha extracts revealed some activity against S. aureus and E. faecalis. Evaluation of the minimal inhibitory concentration (MIC) by using a serial dilution microplate method indicated low antibacterial activity (MIC > 2.5 mg/ml). Thongolifha therefore does not contain antibacterial compounds but there may be present in a low concentration or the serial dilution microplate method does not work well with insects extracts. Some insects contain peptides as antibacterial compounds. Spraying thongolifha extracts chromatograms with several spraying reagents indicated that these antibacterial compounds were not peptides Methanol crude leaf extracts of D. viscosa was reported in the literature to have antibacterial activity against S. aureus however the results were obtained by using the agar diffusion method which does not provide convincing quantitative results. In our study we extracted components from D. viscosa using solvents of varied polarities to evaluate its antibacterial and antioxidant activities. Dichloromethane and acetone extracted more compounds with good antibacterial activity against S. aureus, E. faecalis, E. coli and P. aeruginosa. The average MIC values varied from 0.04 to 0.28 mg/ml, indicating excellent to good antibacterial activity. The antioxidant activity using the DPPH Spectrophotometric assay gave the EC50 of the extracts of 212 ± 4 to 469 ± 9 µg/ml. As expected, the more polar crude extracts, ethyl acetate and acetone demonstrated higher activity compared to other extracts. This was supported by the TLC qualitative assay showing more yellow bands in these extract on TLC chromatograms after spraying with 0.2% DPPH in methanol. To determine whether thongolifha has sequestered compounds from the host plant, D. viscosa, a serial exhaustive extraction was performed in order to extract components from the crude extracts of both insect and the host plant by using various solvents and separating the extracts on TLC plates by using various eluant systems. After the TLC chromatograms were sprayed with vanillin-sulphuric acid to reveal separated components, there were few similarities of components from both insect and host plant. This could mean that either a sequestered plant compounds are present in low quantities in the insect extract, that insect may have metabolized the sequestered compounds or alternatively that the insect might not have sequestered the compounds from the host plant at all. It should be kept in mind that the stink-bugs feed by sucking sap from the host plant. By using bioassay-guided fractionation based mainly on silica gel chromatography, four compounds (5-hydroxy-3,74’-trimethoxyflavone (1); 5,7-dihydroxy-3,6,4’-trimethoxyflavone (2); 5,7,4’-trihydroxy-3,6-dimethoxyflavone (3); and 4’-O-methylkaempferol (4) where isolated from dichloromethane fraction of a crude D. viscosa leaf extract, acetone crude leaf extract yielded only one compound, Kaempferol (5). Compounds 1, 2, 3 and 5 where previously isolated from D. viscosa whereas compound 4 was isolated for the first time from D. viscosa. Compounds 4 is not a novel compound because it was previously isolated from other plants species such as the Lens culinaris. Compounds 3, 4 and 5 have good antibacterial activity against E. coli and E. faecalisat MIC values of 15.63 µg/ml and 31.25 µg/ml respectively. In addition, the DPPH quantitative assay has demonstrated that Compounds 4 and 5 have strong antioxidant activities (EC50 = 35.1 ± 0.85 and 75.5 ± 1.76 µM respectively) but lower than L-ascorbic acid (EC50 = 13.5 ± 0.28 µM) used as a standard antioxidant agent. The antibacterial and antioxidant activity of most of the isolated compounds were not known previously. Investigation of structure antibacterial-activity relationship in the isolated compounds did not yield a clear correlation. When investigating the possible interaction between the insect and the host plant, bioautography assay has shown compounds with antibacterial activity against S. aureus (Rf 0.79) E. faecalis (Rf 0.66) when separated with CEF eluent system. Some of the isolated compounds from D. viscosa leaf extracts had an Rf of 0.79 (5, 7-dihydroxy-3, 6, 4’-trimethoxyflavone) and Rf 0.61 (5, 7, 4’-trimethoxxyflavone) when separated with CEF eluent system. These findings indicate that thongolifha may have sequestered the two compounds from D. viscosa leaves, but this possibility has to be confirmed. This study has indicated that thongolifha is good source of protein, vitamins, minerals and amino acids; however we have not found evidence of significant antibacterial activity of thongolifha. If fresh material of thongolifha can be analysed in future work the probability of finding medicinal properties may be greater. On the other hand, D.viscosa. crude leaf extracts have demonstrated strong antibacterial and antioxidant activities; although isolated compounds have shown moderate level of activities. Because practically all antibacterial compounds based on bioautography have been isolated, it is clear that in the crude dichloromethane extract some synergism must have taken place because the antibacterial activity on a mass basis was nearly as good as the isolated compound without removing >90% of non active compounds.
Thesis (PhD (Paraclinical Science))--University of Pretoria, 2006.
Paraclinical Sciences
PhD
unrestricted

Para verificar a toxidez e o quadro clínico e patológico da intoxicação por Dodonea viscosa em bovinos, a planta foi administrada para cinco bovinos onde quatro receberam folhas verdes e um recebeu folhas secas. Quatro dos bovinos que receberam as folhas verdes e seca apresentaram sinais clínicos e morreram. Um bovino não adoeceu e nem morreu. A planta mostrou-se tóxica a partir de 25g/kg de peso vivo. As folhas secas fornecidas na dose de 30g/kg mantiveram a toxidez. O menor período de evolução clínica nos que morreram foi de 3 horas e o maior foi de 19 horas.A evolução clínica foi cerca de 8,5h até a morte. O início dos sinais clínicos variou de 13 horas e 30 minutos a 45 horas. Os animais manifestaram apatia, anorexia, leve tenesmo, dificuldade para se manter em estação apoiando-se contra obstáculos, tremores musculares, decúbito esternal, movimentos de pedalagem, coma e morte. A alteração macroscópica mais significativa foi observada no fígado, que apresentava padrão lobular acentuado caracterizada por alternação de áreas vermelho-escuras,com o centro mais deprimido, intercaladas com áreas amarelo-claras conferindo ao órgão o aspecto de noz–moscada. Hemorragias petequiais foram encontradas em serosas de órgãos da cavidade abdominal e torácica e no intestino. A principal alteração microscópica foi observada no fígado que apresentou necrose coagulativa centrolobular ou massiva, associada à congestão e hemorragia.

Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine. Johannesburg 2012.
Dental caries and periodontal diseases are the most common bacterial oral infections in humans. Prevention and treatment of these infections are oral hygiene measures including antimicrobial compounds which can be chemical agents or natural products. Dodonaea viscosa var. angustifolia is an indigenous South African plant that has antibacterial, antiviral and anticandida properties. This study investigated the antibacterial and antivirulence effect of D. viscosa var. angustifolia on cariogenic bacteria and the causative organisms of periodontal diseases.

This item is only available electronically.
The variation in distribution and abundance of leaf wax n-alkanes has been proposed as a proxy for palaeoclimate. Understanding environmental controls on the variation in distribution and abundance of leaf wax n-alkanes is therefore necessary to determine if this is a robust tool for extracting climatic information from palaeo archives. Results of previous work to create a modern baseline for this proxy have, in some cases, been confounded by differences in species or plant type between sites or along gradients. This study investigates leaf wax n-alkane variation within a species of Australian shrub, Dodonaea viscosa, which inhabits a wide range of climatic conditions. Leaf wax n-alkane data from 43 individuals of D. viscosa were analysed from a climatic gradient ranging from central Australia to Kangaroo Island, with a mean annual temperature range of 13.9—22.7 °C and precipitation range of 164—808 mm/yr. Concentration of n-alkanes increase with increasing temperature along the gradient. Annual mean aridity index has the strongest relationship with the average chain length (ACL) of leaf wax n-alkanes and suggests that water availability is a strong driver of variation in ACL. In addition to n-alkane data, carbon isotope ratio (δ13C) and specific leaf area (SLA) data were measured to determine if this species shows predictable responses to these established and climatically sensitive leaf traits. Predicted responses in δ13C and SLA are observed in this species. Only weak effects of subspecies on leaf trait relationships with climate are found in this study. Scanning electron microscopy was used to qualitatively assess differences in leaf wax microstructure with climate and produced inconclusive results. Distributions of leaf wax n-alkanes have great potential as a proxy for palaeoclimate. Results presented here support the use of n-alkane ACL variation to detect aridity rather than temperature.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2015

Degree of Master of Science in Medicine by research only Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine Johannesburg 2016
Introduction: The link between Streptococcus mutans and dental caries is well documented. The use of natural plant products in the treatment of oral diseases is gaining popularity. One plant that has gained recognition as a source of traditional medicine is Dodonaea viscosa var. angustifolia. The aim of this study was to analyse the phytochemical constituents of D. viscosa var. angustifolia (DVA) and establish their beneficial effects against S. mutans. Materials and methods Cultures of S. mutans ATCC 10923 and SM1 were obtained from the Oral Microbiology laboratory and the DVA was collected from the Pypeklipberg, Mkhunyane Eco Reserve, South Africa. Dry DVA leaves were extracted with methanol. The crude extract was fractionated into six fractions (F1-F6) using silica gel column chromatography and thin layer chromatography. The Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) of the crude extract and six fractions were determined using microtitre plate dilution technique. The effect of the crude extract and fractions on biofilm formation and acid production were investigated using standard techniques. The bioautography technique was also used to identify fractions with bioactive compounds. The most active fraction (F5) was further fractionated and purified into two subfractions, 5.1 and 5.2. Both subfractions were further screened to identify the most beneficial subfraction (5.1). Subfraction 5.1 was identified and elucidated using GC-MS and NMR. The effect of the purified compound on biofilm formation and acid production on S. mutans was repeated to establish reproducibility of the results. Cytotoxic effect of the crude extract and identified subfraction (5.1) was studied using human embryonic kidney cells (HEK). The results were analyzed using Wilcoxon rank-sum test (Mann-Whitney). Results The MIC and MBC of the six fractions and crude extract ranged from 0.39 to 12.5 mg/ml. On preliminary screening of 6 fractions, F5 showed lowest MBC of 0.39 mg/ml and highest total activity value of 2000. In addition, at 0.2 mg/ml, F5 reduced biofilm formation by 93.3% and reduced acid production in S. mutans. Purification of F5 produced subfraction 5.1 and 5.2. Subfraction 5.1 showed higher antimicrobial activity (MIC-0.05 mg/ml) compared to the crude extract (MIC-0.78 mg/ml) and subfraction 5.2 (MIC-0.78 mg/ml). At a concentration of 0.05 mg/ml, subfraction 5.1 exhibited an inhibitory effect on biofilm formation at both 6 hours (94% reduction) and 24 hours (99% reduction) which was higher compared to the crude extract (87% reduction at 0.78 mg/ml after 6 hours). Subfraction 5.1 also exhibited a higher inhibitory effect on acid production compared to the crude extract. Subfraction 5.1 was identified as, 5,6,8-Trihydroxy-7,4l-dimethoxyflavone. Cytotoxicity analysis of the crude extract and subfraction 5.1 (5,6,8-Trihydroxy-7,4l-dimethoxyflavone) on HEK 293 cells showed IC50 values of 0.09 mg/ml and 0.03 mg/ml respectively. Conclusion Phytochemical analysis of D. viscosa var. angustifolia produced an anticariogenic constituent, 5,6,8-Trihydroxy-7,4l-dimethoxyflavone. The compound showed improved antimicrobial and anticariogenic activity at lower concentrations than the crude extract. At subinhibitory concentrations, the compound significantly inhibited biofilm formation and acid production by S. mutans. Cytotoxicity analysis established the safe use of this newly isolated compound therefore it has potential to be used in the oral cavity to prevent dental caries.
MT2016