Thesis (MSc (Biomedical Technology))--Cape Peninsula University of Technology, 2018. / The challenge of antimicrobial resistance has increased drastically over the years as more microorganisms are becoming resistant to the available conventional treatments. The burden of antimicrobial resistant infections is intensified by the increase in immunocompromising conditions such as HIV/AIDS and cancer. Due to this challenge, pharmaceutical companies, health sectors and researches are in search of new antimicrobial agents that can solve the problem at hand. Medicinal plants are a reliable source for drug discovery as it is estimated that 25% of modern medicine originated from plants. They have also been used traditionally as sources of medicine in the treatment of many human ailments. Plants can also be applied in the field of nanotechnology. Nanotechnology is a promising field in medicine as it has the potential to offer improved methods for disease diagnostics and therapeutics. The use of plants in nanotechnology brings about biologically friendly nanomaterials. Cotyledon orbiculata is one of the well-known and common plants of South Africa that is used in traditional medicinal practices. The nanotechnology applications as well as the antimicrobial and immunomodulatory effects of this plant were evaluated. The ability of C. orbiculata to synthesize silver nanoparticles was determined. Optimisation of silver nanoparticle synthesis using water extract of C. orbiculata was done at different conditions. The conditions evaluated include, reaction temperature (25 and 70°C), silver nitrate concentration (1 and 3mM), plant extract concentration (1.5, 3 and 6mg/ml) and reaction time. The synthesis of silver nanoparticles using this plant was successful. The optimal conditions for the synthesis of silver nanoparticles using C. orbiculata were 3mg/ml of the C. orbiculata extract, 3mM silver nitrate at a reaction temperature of 70°C for 2 hours. Under these conditions, spherical, crystalline nanoparticles with sizes of 20-40nm were produced. The antimicrobial and immunomodulatory properties of C. orbiculata extracts and silver nanoparticles were evaluated. Antimicrobial activity was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Methicillin resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Candida albicans, using the micro-dilution assay to determine the minimum inhibitory concentration (MIC). The results obtained revealed that all extracts of C. orbiculata have antimicrobial properties against all the microorganisms tested. The MICs of the extracts ranged from 3.13 to 50mg/ml and the MBC/MFC from 6.25 to >100mg/ml. The methanol extract exhibited better antimicrobial activity in comparison to the others extracts whereas the water extract had better antifungal properties. The chloroform extract showed the lowest activity in both antibacterial and antifungal studies. Silver nanoparticles also exhibited antimicrobial activity against all the microorganisms tested. It’s MICs against these microorganisms ranged from 5–80μg/ml and MBC/MFC from 20-160μg/ml. The silver nanoparticles were highly active than the water extract against both the bacteria and the fungi. Immunomodulatory effects of the plant extracts and silver nanoparticles were determined by evaluating cytokine production using the enzyme linked immunoassay (ELISA) assay. All the extracts and silver nanoparticles of C. orbiculata were found to have anti-inflammatory properties. The water extracts showed more anti-inflammatory activity against the cytokines than the other extracts. However the silver nanoparticles were more active than the water extract. The findings from this study confirmed that C. orbiculata have antimicrobial and immunomodulatory effects. This provided scientific evidence of the traditional use of this plant in the treatment of skin infections and inflammatory conditions.

Thesis (PhD (Biomedical Sciences))--Cape Peninsula University of Technology, 2017. / The use of medicinal plants in the management of various health problems date back to the ancient times. However, only in recent years, researchers are starting to focus on the use of natural plant products as alternative treatment in disease control. Basella alba (Ba), commonly called Ceylon or Indian spinach is one of such medicinal plants, wildly cultivated and consumed mostly as vegetable. Studies have established many beneficial effects of Ba, including androgenic effects as well as antidiabetic effects which have been described in rats following oral administration of the leave extract. However, the actual mechanisms underlying the antihyperglyceamic effect of Ba have not been reported in any study and little or no research details are yet available on the potential beneficial effects of Ba in reproductive dysfunction resulting from diabetes mellitus. This study was aimed at investigating the mechanisms underlying the antidiabetic effect of Ba and the possibility of a role for the plant in correcting diabetic-induced reproductive dysfunctions in male Wistar rats. The first part of the study involved comparing of three different solvent extracts of Ba leaves namely ethyl acetate, methanolic and aqueous extracts for their antioxidant potentials, after which the aqueous extract was selected for further use in the experiments. Animal experimentation involved male rats (n=40) aged 8-10 weeks, randomly divided into four equal groups as follows: Healthy Control, Diabetic Control, Healthy Treatment and Diabetic Treatment. Diabetes was induced via a single intraperitoneal injection of streptozotocin (55mg/kg) and all animals subsequently received treatment via gavage (Rats in Control groups received 0.5ml/100g normal saline daily and treatment groups received 200mg/kg plant extract daily) for a period of four weeks. Fasting blood sugar and body weights were recorded weekly throughout the study. Animals were sacrificed upon completion of the treatment and blood samples and tissues collected for further analysis which included computer aided sperm analysis, Luminex® technology and enzyme-linked immunosorbent hormonal assays, inflammatory cytokine assays, analysis of oxidative stress markers and Histopathological analysis. The single intraperitoneal injection of a high streptozotocin dose resulted in hyperglycaemia, weight loss, subnormal sperm parameters, negative balance of inflammatory cytokines and endogenous antioxidants and degenerative changes in the pancreas, testes and epididymis as observed in the diabetic control rats. Oral administration with the aqueous extract of Ba for four weeks in diabetic treatment rats led to a significant reduction in blood sugar and improvement of sperm parameters by modulating the production of gonadal hormones, in vivo antioxidants and inflammatory cytokines. There was also significant recovery of normal islet histology and reduction in testicular and epididymal degeneration in the diabetic treatment rats when compared to their diabetic control counterparts. It was concluded from the findings of this study that the antidiabetic and profertility effects of Ba are largely dependent on the modulation of in vivo production of antioxidants, gonadal hormones and inflammatory cytokines, probably stimulated by one or more phytochemical component(s) that can be isolated in the aqueous extract of the plant

Lam, Hilary. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 182-191). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.I / ABSTRACT --- p.III / TABLE OF CONTENTS --- p.V / LIST OF FIGURES --- p.X / LIST OF TABLES --- p.XIX / LIST OF ABBREVIATIONS --- p.XXII / Chapter Chapter 1: --- LITERATURE REVIEW --- p.1 / Chapter 1. --- Aristolochia --- p.1 / Chapter 1.1 --- "Aristolochia, as a plant" --- p.1 / Chapter 1.2 --- The chemicals in Aristolochia --- p.1 / Chapter 1.3 --- "Aristolochia, as herbal remedies" --- p.3 / Chapter 1.4 --- The Aristolochia poisoning cases --- p.4 / Chapter 1.5 --- The mechanism of AAs --- p.6 / Chapter 1.6 --- Renaming CHN to AAN --- p.6 / Chapter 1.7 --- Banning Aristolochia herbs --- p.7 / Chapter 1.8 --- The possible cause of ANN --- p.8 / Chapter 1.8.1 --- Misuse of Chinese Medicine --- p.8 / Chapter 1.8.2 --- Substitution --- p.9 / Chapter 1.8.3 --- The complexities of the herbal nomenclature --- p.9 / Chapter 1.8.4 --- Adulteration --- p.11 / Chapter 1.9 --- Methods for authenication --- p.12 / Chapter 1.9.1 --- Traditional methods for authentication --- p.12 / Chapter 1.9.2 --- The advantage of using molecular methods --- p.13 / Chapter 1.9.2.1 --- DNA fingerprinting --- p.13 / Chapter 1.9.2.2 --- DNA sequencing --- p.15 / Chapter 1.10 --- Method selection rationale --- p.15 / Chapter 1.11 --- The need for molecular authentication of six medicinal herbs --- p.17 / Chapter 1.11.1 --- The herb Mutong --- p.17 / Chapter 1.11.1.1 --- The poisoning cases reported --- p.19 / Chapter 1.11.1.2 --- Other authentication studies of Mutong --- p.19 / Chapter 1.11.2 --- The herb Muxiang --- p.20 / Chapter 1.11.2.1 --- Chemical profile --- p.21 / Chapter 1.11.2.2 --- Other authentication studies of Muxiang --- p.21 / Chapter 1.11.3 --- The herb Baiying --- p.22 / Chapter 1.11.3.1 --- The poisoning cases reported --- p.23 / Chapter 1.11.3.2 --- Other authentication studies of Baiying --- p.24 / Chapter 1.11.4 --- The herb Fangj --- p.i 24 / Chapter 1.11.4.1 --- Chemical profile --- p.25 / Chapter 1.11.4.2 --- The poisoning cases reported --- p.26 / Chapter 1.11.5 --- The herb Madouling --- p.26 / Chapter 1.11.6 --- The herb Zhushalian --- p.27 / Chapter 1.12 --- Aristolochia specific markers --- p.28 / Chapter 1.13 --- Significance of the research --- p.29 / Chapter Chapter 2: --- OBJECTIVE --- p.30 / Chapter Chapter 3: --- MATERIALS AND METHODS --- p.31 / Chapter 3.1 --- Samples source --- p.31 / Chapter 3.2 --- Total DNA extraction --- p.39 / Chapter 3.2.1 --- Cetyltriethylammonium bromide extraction --- p.39 / Chapter 3.2.2 --- Commercial kit extraction --- p.40 / Chapter 3.3 --- DNA amplification --- p.42 / Chapter 3.4 --- DNA fingerprinting --- p.43 / Chapter 3.4.1 --- DNA concentration determination --- p.43 / Chapter 3.4.2 --- ISSR fingerprinting --- p.44 / Chapter 3.5 --- Agarose gel electrophoresis --- p.45 / Chapter 3.6 --- Purification of PCR product --- p.46 / Chapter 3.7 --- Cloning of PCR product --- p.47 / Chapter 3.7.1 --- Ligation --- p.47 / Chapter 3.7.2 --- Transformation --- p.48 / Chapter 3.7.3 --- Cell cultivation --- p.48 / Chapter 3.7.4 --- Plasmid extraction --- p.49 / Chapter 3.7.5 --- Insert confirmation --- p.49 / Chapter 3.8 --- DNA sequencing --- p.50 / Chapter 3.8.1 --- Cycle sequencing --- p.50 / Chapter 3.8.2 --- Purification of cycle sequencing product --- p.51 / Chapter 3.8.3 --- DNA analysis --- p.51 / Chapter 3.9 --- Sequence analysis --- p.52 / Chapter Chapter 4: --- AUTHENICATION OF MUTONG --- p.53 / Chapter 4.1 --- Results --- p.53 / Chapter 4.1.1 --- Sequence alignment --- p.54 / Chapter 4.1.1.1 --- trnL-trnF sequences --- p.54 / Chapter 4.1.1.2 --- psbA-trnH sequences --- p.55 / Chapter 4.1.2 --- Percentage similarity analysis --- p.64 / Chapter 4.1.3 --- Dendrogram analysis --- p.67 / Chapter 4.2 --- Discussion --- p.73 / Chapter 4.2.1 --- Evaluation of chloroplast trnL-trnF region in differentiation of Mutong --- p.73 / Chapter 4.2.2 --- Evaluation of chloroplast psbA-trnH region in differentiation of Mutong --- p.74 / Chapter 4.2.3 --- Evaluation of using DNA sequencing in differentiation of Mutong --- p.75 / Chapter 4.3 --- Conclusion --- p.77 / Chapter Chapter 5: --- AUTHENICATION OF MUXIANG --- p.78 / Chapter 5.1 --- Results --- p.78 / Chapter 5.1.1 --- Sequence alignment --- p.79 / Chapter 5.1.1.1 --- trnL-trnF sequences --- p.79 / Chapter 5.1.1.2 --- psbA-trnH sequences --- p.80 / Chapter 5.1.2 --- Percentage similarity analysis --- p.88 / Chapter 5.1.3 --- Dendrogram study --- p.91 / Chapter 5.2 --- Discussion --- p.97 / Chapter 5.2.1 --- Evaluation of chloroplast trnL-trnF region in differentiation of Muxiang --- p.97 / Chapter 5.2.2 --- Evaluation of chloroplast psbA-trnH region in differentiation of Muxiang --- p.99 / Chapter 5.3 --- Conclusion --- p.100 / Chapter Chapter 6: --- AUTHENICATION OF BAIYING --- p.102 / Chapter 6.1 --- Results --- p.102 / Chapter 6.1.1 --- Sequence alignment --- p.103 / Chapter 6.1.2 --- Percentage similarity analysis --- p.107 / Chapter 6.1.3 --- Dendrogram analysis --- p.107 / Chapter 6.2 --- Discussion --- p.109 / Chapter 6.2.1 --- Evaluation of chloroplast psbA-trnH region in differentiation of Solarium and Aristolochia --- p.109 / Chapter 6.2.2 --- Molecular authentication of Baiying --- p.112 / Chapter 6.3 --- Conclusion --- p.113 / Chapter Chapter 7: --- AUTHENICATION OF FANGJI --- p.114 / Chapter 7.1 --- Results --- p.114 / Chapter 7.1.1 --- Sequence alignment --- p.115 / Chapter 7.1.1.1 --- trnL-trnF sequence --- p.115 / Chapter 7.1.1.2 --- psbA-trnH sequence --- p.116 / Chapter 7.1.2 --- Percentage similarity analysis --- p.123 / Chapter 7.1.3 --- Dendrogram study --- p.126 / Chapter 7.2 --- Discussion --- p.132 / Chapter 7.2.1 --- Evaluation of chloroplast trnL-trnF region in differentiation of Fangji --- p.132 / Chapter 7.2.2 --- Evaluation of chloroplast psbA-trnH region in differentiation of Fangji --- p.133 / Chapter 7.3 --- Conclusion --- p.133 / Chapter Chapter 8: --- AUTHENICATION OF MADOULING --- p.135 / Chapter 8.1 --- Results --- p.135 / Chapter 8.1.1 --- Sequence alignment --- p.136 / Chapter 8.1.1.1 --- trnL-trnF sequence --- p.136 / Chapter 8.1.1.2 --- psbA-trnH sequence --- p.136 / Chapter 8.1.2 --- Percentage similarity analysis --- p.143 / Chapter 8.1.3 --- Dendrogram study --- p.146 / Chapter 8.2 --- Discussion --- p.152 / Chapter 8.2.1 --- Evaluation of chloroplast trnL-trnF region in differentiation of Madouling --- p.152 / Chapter 8.2.2 --- Evaluation of chloroplast psbA-trnH region in differentiation of Madouling --- p.153 / Chapter 8.3 --- Conclusion --- p.153 / Chapter Chapter 9: --- AUTHENICATION OF ZHUSHALIAN --- p.155 / Chapter 9.1 --- Results --- p.155 / Chapter 9.1.1 --- Sequence alignment --- p.156 / Chapter 9.1.1.1 --- trnL-trnF sequence --- p.156 / Chapter 9.1.1.2 --- psbA-trnH sequence --- p.157 / Chapter 9.1.2 --- Percentage similarity analysis --- p.157 / Chapter 9.1.3 --- Dendrogram study --- p.162 / Chapter 9.2 --- Discussion --- p.166 / Chapter 9.2.1 --- Evaluation of chloroplast trnL-trnF region in differentiation of Zhushalian --- p.166 / Chapter 9.2.2 --- Evaluation of chloroplast psbA-trnH region in differentiation of Zhushalian --- p.171 / Chapter 9.3 --- Conclusion --- p.171 / Chapter Chapter 10: --- ARISTOLOCHIA SPECIFIC MARKER --- p.172 / Chapter 10.1 --- ISSR fingerprinting --- p.172 / Chapter 10.2 --- Discussion --- p.178 / Chapter Chapter 11: --- CONCLUSION --- p.180 / BIBLIOGRAPHY --- p.182 / APPENDIX - MATERIALS PREPARATION --- p.192

Yu, Jing. / "November 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 161-172). / Abstracts in English and Chinese. / Abstract --- p.I / 摘要 --- p.III / Acknowledgements --- p.V / Contents --- p.VI / List of Figures --- p.VIII / List of Tables --- p.X / Abbreviations and Symbols --- p.XII / Chapter CHAPTER 1 --- Introduction --- p.1 / Chapter 1.1 --- Phylogenetic study of Hedyotis --- p.2 / Chapter 1.1.1 --- Rubiaceae --- p.2 / Chapter 1.1.2 --- Controversial taxonomic issues --- p.9 / Chapter 1.2 --- Traditional Chinese medicine (TCM) --- p.19 / Chapter 1.2.1 --- Introduction --- p.19 / Chapter 1.2.2 --- Baihuasheshecao --- p.20 / Chapter 1.2.3 --- Authentication of Baihuasheshecao --- p.23 / Chapter 1.3 --- Icefishes in the Hong Kong market --- p.23 / Chapter 1.3.1 --- Introduction --- p.23 / Chapter 1.4 --- Molecular approach --- p.25 / Chapter 1.4.1 --- Introduction to molecular phylogeny --- p.25 / Chapter 1.4.2 --- FINS (Forensically Informative Nucleotide Sequencing) for species identification --- p.27 / Chapter 1.4.3 --- DNA sequence markers --- p.28 / Chapter 1.5 --- Objectives --- p.38 / Chapter CHAPTER 2 --- MATERIALS AND METHODOLOGY --- p.41 / Chapter 2.1 --- Materials --- p.42 / Chapter 2.2 --- DNA extraction --- p.50 / Chapter 2.3 --- Polymerase chain reaction (PCR) method --- p.51 / Chapter 2.4 --- Gel electrophoresis --- p.54 / Chapter 2.5 --- PCR production purification --- p.54 / Chapter 2.6 --- Ligation and transformation and transformation of PCR product --- p.56 / Chapter 2.7 --- DNA sequencing and sequence analyses --- p.58 / Chapter CHAPTER 3 --- USING FORENSICALLY INFORMATIVE NUCLEOTIDE SEQUENCING (FINS) TECHNOLOGY FOR SPECIES IDENTIFICATION --- p.64 / Chapter 3.1 --- Authentication of Baihuasheshecao by FINS Analysis --- p.65 / Chapter 3.1.1 --- Authentication using FINS technology --- p.65 / Chapter 3.1.2 --- Relative effectiveness of DNA regions for FINS analysis --- p.70 / Chapter 3.1.3 --- Phylogenetic interpretation --- p.72 / Chapter 3.2 --- Authentication of Salangids (Icefishes) by FINS Analysis --- p.74 / Chapter 3.2.1 --- Analysis based on mitochondrial ribosome DNA region --- p.74 / Chapter 3.2.2 --- Analysis based on mitochondrial 16S rRNA --- p.77 / Chapter 3.2.3 --- Analysis based on combined regions --- p.79 / Chapter 3.2.4 --- Phylogenetic analysis --- p.81 / Chapter 3.2.5 --- Discussion --- p.85 / Chapter 3.3 --- Conclusions --- p.88 / Chapter CHAPTER 4 --- PHYLOGENTIC STUDY OF HEDYOTIS IN CHINA AND THEIR POSITION IN SPERMACOCEAE --- p.89 / Chapter 4.1 --- Phylogentic study of Hedyotis species in Chinese --- p.90 / Chapter 4.1.1 --- Nuclear ITS region --- p.90 / Chapter 4.1.2 --- Plastid trnL intron and trnL-V intergenic spacer region --- p.94 / Chapter 4.1.3 --- Plastid trnH-psbA intergenic spacer region --- p.98 / Chapter 4.1.4 --- Plastid rbcL region --- p.102 / Chapter 4.1.5 --- Plastid matK region --- p.106 / Chapter 4.1.7 --- Combined analysis --- p.114 / Chapter 4.2 --- The phylogenetic position of Hedyotis (species in China) in the tribe of Spermacoceae s.1 --- p.121 / Chapter 4.2.1 --- Plastid trnL - F intergenic spacer region --- p.121 / Chapter 4.2.2 --- Plastid rbcL region --- p.133 / Chapter 4.2.3 --- Plastid rps16 region --- p.141 / Chapter 4.3 --- Discussion --- p.153 / Chapter 4.3.1 --- Comparison of phylogenetic utility of the six DNA regions --- p.153 / Chapter 4.3.2 --- Diplophragma section --- p.154 / Chapter 4.3.3 --- "Hedyotis, Dimetia, Euoldendandia and Gonotheca sections" --- p.156 / Chapter 4.3.4 --- The position of Hedyotis (species in China) in Spermacoceae --- p.158 / Chapter 4.4 --- Conclusions --- p.160 / REFERENCES --- p.161 / APPENDIX --- p.173

Thesis (M.Sc. (Biochemistry) -- University of Limpopo, 2018 / Dicerocaryum senecioides is a plant widely used as a nutritional source. It is used also for treatment of measles, wounds and to facilitate birth in domestic animal and humans in many parts of southern Africa (Mampuru et al., 2012). Findings in our laboratory have shown that a dichloromethane fraction of D. senecioides possesses antiinflammatory properties in human t-lymphocytes (Madiga, 2009), while the methanol crude extract possesses anti-proliferative and proapoptotic properties against Jurkat T cancer cells (Mphahlele, 2008). In this study, the probable anti-cancer effect of D. senecioides crude methanol leaf extract was investigated on cervical HeLa cancer cells. Dried powdered leaves of D. senecioides were extracted with absolute methanol to obtain a crude extract. To assess the cytotoxicity effect of the extract, KMST-6 and HeLa cell cultures were exposed to various extract concentrations (0 to 600 µg/ml) for 24 and 48 hours and subjected to the MTT assay. The results showed the extract to have no significant increase in the viability inhibition of HeLa cells at all tested concentrations after 24 hours of treatment. However, treatment with 400, 500 and 600 µg/ml of the extract for 48 hours revealed significantly increased HeLa cell viability inhibition. Furthermore, the extract showed to have no effect on the viability of normal human fibroblast KMST-6 cells at concentrations below 600 µg/ml, after 24 and 48 hours of treatment, thus showing selective cytotoxicity of the extract. To determine the mode of cell death associated with the increase in HeLa cell viability inhibition, the Hoechst 33258 nuclear staining assay and inverted light microscopy were employed. The data proposed apoptosis as the mode of cell death associated with the inhibition of HeLa cell viability. This was evidenced by changes in cell morphology such as the loss of HeLa cell radial extensions, cell shrinkage, as well as nuclear morphological features such as chromatin condensation. Apoptosis induction was further confirmed by the annexin-V/PI and multicaspase assays, using flow cytometry. The results showed an increase in the percentage of cells stained with annexin-V/PI, as well as increased caspase activity in extract-treated HeLa cells. To elucidate proapoptotic mechanisms of the extract, Western blotting analysis as well as the human apoptosis antibody array kit were used. This was to measure the expression profile of a number of apoptosis regulatory proteins. The results demonstrated modulation of some anti- and pro-apoptotic proteins, as well as the release of mitochondrial proteins required xiii for initiation of apoptosis, in the cytoplasm. The D. senecioides extract showed to have no effect on the cell division cycle of HeLa cells as determined by the PI staining assay. In conclusion, D. senecioides crude methanol leaf extract induced some degree of apoptosis in cervical HeLa cancer cells via the intrinsic apoptosis pathway. This was by modulating some of the members of the Bcl-2 family of proteins, which, facilitated the release of cytochrome C and activation of a caspase cascade. / South African Medical Research Council (SAMRC)

Ce travail a porté sur la bio-analyse de plantes médicinales Djiboutiennes. Ces dernières ont été sélectionnées sur des critères ethnobotaniques appliqués sur les plantes utilisées traditionnellement contre les infections microbiennes. Cette sélection a retenu six plantes qui ont ensuite subi un screening antibactérien et anti oxydant. Les résultats de ce screening ont conduit à étudier trois plantes: Acacia seyal, Indigofera caerulea et Cymbopogon commutatus. La recherche des composés de l’Acacia seyal est effectuée au moyen d’un bio-guidage. Deux extraits, aqueux et méthanolique, de l’écorce de cette plante sont évalués pour leur activité antibactérienne. Quatre composés sont isolés et caractérisés (épicatéchine, catéchine, catéchine digallique et β-sitostérol) et testés pour leurs activités. Par ailleurs quatre extraits (hexanique, acétonique, méthanolique et aqueux) du fruit d’Indigofera caerulea ont été testés pour leurs activités antibactérienne et anti oxydante. Les extraits hexanique et méthanolique sont les plus actifs. Six composés sont isolés de ces extraits (méthyl gallate, acide gallique, rutine, isoquercétine, kaempférol-3- rutinoside et β-sitostérol). Le méthyl gallate inhibe staphylococcus aureus avec une CMI de 64 µg/ mL. Enfin l’activité de l’huile essentielle de Cymbopogon commutatus est testée sur sept souches bactériennes, deux souches fongiques et onze types de cellules cancéreuses. Sur ces dernières, elle présente une forte cytotoxicité avec des IC50 allant de 0,05 µg/mL sur PC3 et HCT116 (cellules cancéreuses de la prostate et colorectales) et à 0,67 µg/mL sur NCI-N87 (cellule cancéreuse gastrique). De façon surprenante, une activité antibactérienne moyenne est observée. L’analyse GCMS de la partie solubilisée dans le milieu de culture a montré que seuls les composés hydrophiles étaient présents. La formulation d’une micro émulsion a été mise au point et les IC50 ont diminué jusqu’à une centaine de fois. Nous avons montré que cette huile essentielle renferme plus de 73,9 % de pipéritone (monoterpène). En conclusion, ces trois plantes ont montré des activités antimicrobiennes, et les travaux confirment leurs utilisations traditionnelles. En plus, nous avons montré qu’elles possèdent d’autres activités biologiques (anti oxydante et anti cancéreuse). Ces résultats devront contribuer à la mise en place d’une pharmacopée traditionnelle et à des formulations de ‘médicaments traditionnels améliorés’ (MTA) / This research focused on the bio-analysis of Djiboutian medicinal plants. These latter were selected on ethnobotanical criteria applied to the plants traditionally used against microbial infections. This selection retained six plants which were then subjected to a biological screening including antibacterial and anti-oxidant activities. Three plants were finally study: Acacia seyal, Indigofera caerulea and Cymbopogon commutatus. The search of compound in Acacia seyal was carried out by means of bio-guidance. Two extracts, aqueous and methanolic, of the bark of this plant were evaluated for their antibacterial activity. Four compounds were isolated, characterized (epicatechin, catechin, digallic catechin and β-sitosterol) and tested for their activity. Also four extracts (hexanic, acetonic, methanolic and aqueous) of the fruit of Indigofera caerulea were tested for their antibacterial and antioxidant activities. The Hexanic and methanolic extracts were the most active. Six compounds were isolated from these extracts (methyl gallate, gallic acid, rutin, isoquercetin, kaempferol-3-rutinoside and β-sitosterol). Methyl gallate inhibited Staphylococcus aureus with a MIC of 64 μg / mL. Finally, the activity of the essential oil of Cymbopogon commutatus was evaluated on seven bacterial strains, two fungal strains and eleven types of cancer cells. On the latter, it exhibits a high cytotoxicity with IC50s ranging from 0.05 μg / mL on PC3 and HCT116 (prostate and colorectal cancer cells) to 0.67 μg/mL on NCI-N87 (gastric cancer cell). Surprisingly, an antibacterial activity not so high was observed. GCMS analysis of the solubilized part in the culture medium showed that only the hydrophilic compounds were present. The formulation of a microemulsion was performed and the IC50 decreased to a hundred times. We have found that this essential oil contained more than 73.9 % piperitone (monoterpene). In conclusion, these three plants showed antimicrobial activities and the work confirms their traditional uses. In addition, we have shown that they have other biological activities (anti-oxidant and anti-cancer). These results should contribute to the establishment of a traditional pharmacopoeia and formulations of 'improved traditional medicines' (MTAs)

Orientador: Carmen Sílvia Fernandes Boaro / Banca: Márcia Ortiz Mayo Marques / Banca: Luiz Fernando Rolim de Almeida / Resumo: A família Lamiaceae se destaca pela utilização de muitas de suas espécies como medicinais, condimentares, aromáticas e ornamentais. Entre elas, a Mentha piperita L., produz óleo essencial amplamente utilizado nas indústrias farmacêuticas, de bebidas alcoólicas, alimentícias e de cosméticos. Leonurus sibiricus L., além de medicinal, é conhecida pela produção de terpenóides e substâncias fenólicas com efeitos alelopáticos, apresentando-se também como planta invasora. O presente estudo objetivou avaliar a atividade do extrato metanólico de folhas de L. sibiricus, no desenvolvimento, trocas gasosas e metabólitos do óleo essencial de M. piperita, cultivada em solução nutritiva. Para tanto, foram utilizadas concentrações iguais a 25, 50 e 100 mg L-1 de extrato metanólico das folhas de L. sibiricus no cultivo hidropônico da M. piperita durante parte de seu ciclo de desenvolvimento. As variáveis, comprimento de parte aérea, área foliar, massa seca dos diferentes órgãos, razão de área foliar, razão de massa foliar, área foliar específica, taxa assimilatória líquida, taxa de crescimento relativo, distribuição de massa seca para os diferentes órgãos, trocas gasosas, e composição química dos óleos essenciais foram avaliadas em diferentes épocas. Os resultados obtidos permitiram concluir que as menores concentrações do extrato metanólico de L. sibiricus, 25 e 50 mg L-1, estimularam o desenvolvimento da M. piperita, estimulando a translocação de matéria orgânica nas plantas, enquanto esse processo prejudicado nas plantas cultivadas com 100 mg L-1, pode ter sido responsável por seu menor desenvolvimento. As trocas gasosas da M. piperita foram influenciadas pela presença do extrato metanólico e estimuladas pelas concentrações iguais a 25 e 50 mg L-1 do extrato. O extrato metanólico de L. sibiricus influenciou os teores dos componentes do óleo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The family Lamiaceae is known for the use of many species as medicinal, condiments, aromatic and ornamental. Among them, Mentha piperita L. essential oil produces widely used in industries pharmaceutical, beverages, food and cosmetics. Leonurus sibiricus L., besides medicinal, produces terpenoids and phenolic substances with allelopathic effects, what explains its invasive behaviour. The present study aimed to evaluate the activity of methanolic extract of leaves of L. sibiricus in the development, gas exchange and metabolites of essential oil of M. piperita, cultivated in nutritive solution. Thus, were used concentrations of 25, 50 and 100 mg L-1 of methanolic extract of leaves of L. sibiricus in the hydroponic cultivation of M. piperita during part of its development cycle. The variables, shoot length, leaf area, dry matter of different organs, leaf area ratio, leaf weight ratio, specific leaf area, net assimilation rate, relative growth rate, dry matter distribution in several organs, gas exchange and composition of essential oils were evaluates at different times. The results showed that low concentrations of methanolic extract of L. sibiricus, 25 and 50 mg L-1, stimulated the development of M. piperita, stimulating the translocation of organic matter in plants, while this process affected in plants grown with 100 mg L-1, may have been responsible for yours less development. The gas exchange of M. piperita were influenced by the presence of methanolic extract and stimulated by concentrations 25 and 50 mg L-1. The methanolic extract of L. sibiricus influenced the levels of the essential oil components of M. piperita, depending on the concentration used, since, at lower concentrations, the plants showed higher levels of menthone and menthol, thus rendering an oil of quality and plants cultivated in the highest concentration showed higher levels of menthyl acetate and menthofuran... (Complete abstract click electronic access below) / Mestre

Thesis (M.Sc. (Horticulture)) --University of Limpopo, 2012 / Refer to document / the National Research Foundation

Thesis (M.Dev.) --University of Limpopo, 2012 / The main aim or purpose of this study was to look at the ways and the strategies of minimizing\ mitigating the over-harvesting of indigenous medicinal plants in order to use them sustainably. The task of identifying and assessing challenges facing local communities in utilizing and sustaining indigenous medicinal plants in Thengwe village and their implications on environmental conservation and management of natural resources was done during the pilot survey. The environmental field survey was conducted after gaining permission to enter into the identified study areas including the Mutavhatsindi Nature Reserve. The result revealed that most of the indigenous medicinal plants are used for healing, religious, economical and for protection purposes. Most of the indigenous medicinal plants in the study area are depleted and many of them are facing extinction. The study was qualitative in design. Semi-structured interviews and a questionnaire were used. The questionnaire had both open-ended and closed questions. The study area was Thengwe Village in the Mutale Municipality. The existence of medicinal plants is threatened by people `s perceptions and attitudes towards them. For some indigenous medicinal plants, depletion is at a high rate due to over-harvesting and because the plants when traded by herbalists they have a premium price attached to them. Interestingly, perhaps surprisingly, the majority of young people hold negative attitudes towards the indigenous medicinal plants due to poor knowledge of the value of indigenous medicinal plants, in contrast to the elders who appreciate their role and consider them as part of their culture, economy and religion. One of the findings is that medicinal plants were found to be important to the community members as the source of income and creation of jobs for the medicinal collectors who sell the species to traditional healers. For the reason of preserving indigenous medicinal plants and others as the environmental resources, this study recommends that there should be strong intergovernmental relationships between the National, Provincial and Local governments in order to prevent over-harvesting of the medicinal plants. The indigenous medicinal plants are equally important to biodiversity students and researchers who want to study and research indigenous medicinal plants which play an important role in the improvement of the livelihoods of community members. Furthermore, education campaigns within the communities and school learners are recommended to encourage the prevention, sustainability and utilization of the indigenous medicinal plants. Additionally, the legal authorities should be empowered to prosecute all people who may be found illegally in possession of indigenous medicinal plants, as well as endangered and protected species. Heavy fines and charges should be imposed on such culprits. Of importance is the fact that the results and recommendations of this study may facilitate the teaching of environmental education and management of natural resources as well as boost the local economy of the Vhembe district Municipality by showing that medicinal plants in the area can be seen as a viable tourist attraction.

Thesis (M.Sc. (Microbiology)) --University of Limpopo, 2015 / Five plant species: Ziziphus mucronata, Senna italica, Lantana camara, Ricinus communis and Lippia javanica, were selected for this study based on their use in traditional medicine. In preliminary screening, crude extracts were prepared using hexane, dichloromethane (dcm), acetone and methanol. Phytochemical profiles on Thin Layer Chromatography plates of the extracts were obtained by developing the plates in mobile phases of varying polarity. Tests for compounds such as tannins, flavonoids, alkaloids, phlobatannins, terpenes, steroids, cardiac glycosides and saponins were carried out. Antibacterial activity of the extracts was carried out using microdilution assay for Minimum Inhibitory Concentration and bioautography against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis. Antioxidant activity of the extracts was performed using the 2, 2, diphenyl-1-picrylhydrazyl (DPPH) assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay and Phagoburst test were used to investigate the toxic effects and anti-inflammatory activity of the extracts on mouse Raw 264.7 macrophage cells, respectively. The presence of phytochemicals was observed on the chromatograms after the plates were sprayed with vanillin sulphuric acid reagent. The dcm extracts of the plants showed antibacterial activity against the selected bacterial species on the bioautograms. Senna italica and Z. mucronata showed the most activity bands on the bioautograms. Lippia javanica had the lowest MIC average of 0.56 mg/ml. Antioxidant activity was observed in the extracts of L. javanica and R. communis. The extracts promoted proliferation of the mouse macrophage cells Raw 264.7 at concentrations ranging from 0.31 mg/ml and 0.08 mg/ml. Senna italica leaves were selected for isolation of antibacterial compounds. The isolated compound was analysed on 1H and 13C nuclear magnetic resonance (NMR) and Mass Spectrometry (MS) for structural analysis. The structure could not be elucidated due to impurities in the compound but the tentative structure is a branched chain alkane with at least one ether linkage per repeating unit. Therefore the study shows that there are plant components with biological activities against wound infecting bacteria and a single lead compound was identified. / the National Research Foundation