Ethnopharmacological relevance: Indigenous plants such as Tulbaghia violacea(TV) and Allium sativum (garlic) are traditionally used as natural remedies to treat a variety of ailments, including cancer. This study investigated the effects of TV leaf and bulb extracts and garlic extract on a cancerous oesophageal cell line (SNO). Materials and methods: The methylthiazoltetrazolium (MTT) assay was used to determine the IC50 of TV leaf (TVL) (250μg/ml) and TV bulb extracts (TVB) (25μg/ml) and garlic (500μg/ml). Extracts were treated individually and in combination for a period of 24 hours. Oxidative damage and intracellular glutathione levels were assessed using the Thiobarbituric Acid Reactive Substances (TBARS) Assay and GSH-Glo™ Luminometry Assay, respectively. The CellTiter-Glo® Luminescent Cell Viability Assay was used to assess ATP activity. Induction of apoptosis and mitochondrial membrane potential were determined via the Caspase-Glo® 3/7 Assay, Caspase-Glo® 8 Assay, Caspase-Glo® 9 Assay and JC-1 Mitoscreen Assay, respectively. Morphological apoptotic changes were determined using the Hoechst 33342 stain. Expressions of p53, PARP and NFKB activities were determined by western blotting. Results: Bulb and leaf extracts of TV increased lipid peroxidation compared to the control (p>0.05), whilst garlic and combination of TV leaf and bulb (TVB + TVL) extracts significantly decreased lipid peroxidation relative to the control (p< 0.05). Endogenous glutathione levels significantly decreased in all TV treatments compared to the control (p<0.05).However, garlic was accompanied by insignificantly increased intracellular glutathione levels compared to the control (p> 0.05). The percentages of depolarised mitochondria in all treated cells were significantly decreased compared to untreated cells (p< 0.05). ATP levels increased significantly in garlic and combination (TVB + TVL) treated cells as compared to the control (p< 0.05), yet no significant differences were noted in TVL and TVB treatments (p> 0.05). Caspase8 and caspase 9 activities significantly increased in garlic and combination treated cells relative to the control (p<0.05). A similar trend was noted for caspase 3/7 activity in garlic and combination treatments (p< 0.05). However, initiator and executioner activities in TVL (p> 0.05) and TVB (p> 0.05) treatments did not significantly differ from the control (p> 0.05). All treatments (including garlic) resulted in increased DNA fragmentation and condensation. All treatments decreased p53 expression (p< 0.05), PARP expression (p< 0.05) and NFK B expression (p>0.05) compared to the control. Conclusions: All TV extracts and garlic induces apoptosis in the oesophageal cancerous SNO cell line through changes in oxidative stress, antioxidant systems, and nuclear chromatin condensation, as well as through induction of nuclear genes and signalling pathways. Since inhibition of apoptosis is a principal alteration in cancer, induction of apoptosis would result in a decrease in cancer cell growth. Thus, TV could be exploited as a potential anti-cancer agent. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2012.

Treatment of diabetes mellitus is mainly focused on glycaemic control regulated by insulin and takes place in insulin sensitive tissues like skeletal muscle which accounts for 75% of glucose metabolism. Plant derived compounds that have anti-diabetic potential are currently being investigated for diabetes treatment as they are cheap and non-toxic. Oleanolic acid (OA), a triterpene found in a wide variety of plants has been shown to have anti-diabetic effects but its mechanism of action, especially on the insulin signalling cascade has not been fully elucidated. The aim of the present study was to investigate the effects of OA on the PI3K/Akt insulin signalling cascade in skeletal muscle and skin of streptozotocin induced diabetic male Sprague-Dawley rats. Male Sprague-Dawley rats (non-diabetic and diabetic) were treated with insulin (4IU/ kg bw), OA (80 mg/kg bw) and a combination of OA + insulin in an acute and sub-chronic study. The study showed that OA does not reduce blood glucose levels in type 1 diabetic rats but enhances insulin stimulated hypoglycaemic effects. In the acute study OA was shown to activate Akt and dephosphorylate GS in skeletal muscle of streptozotocin induced diabetic rats. In the sub-chronic study OA and OA + insulin increased expression of GS in skeletal muscle of diabetic rats. GP expression was decreased by OA and OA + insulin treatments in skeletal muscle whilst in skin it was increased by both treatments. OA increased both GS and GP in skeletal muscle whilst in skin they were decreased. OA + insulin treatment increased GS and decreased GP activities in skeletal muscle and increased activity of both enzymes in skin of diabetic rats. OA increased the amount of glycogen in both muscle and skin whilst OA + insulin reduced the amount of glycogen. OA and OA + insulin treatment showed some protective effects against liver and muscle damage as there were reductions in serum LDH, ALT and AST levels. In conclusion, oleanolic acid in synergy with insulin can enhance activation of the insulin signalling pathway and there was evidence of OA activation of insulin signaling enzymes independent of insulin. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2013.

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycaemia; this condition is caused by lack of insulin secretion (Type 1) and/or insulin resistance (Type 2). In diabetic patients; carbohydrate, protein and lipid metabolism is disturbed due to the lack of the body’s ability to utilise glucose efficiently. Management of type 1 diabetes involves insulin therapy which may be inconvenient for patients. Therefore alternative methods for management of type 1 diabetes involving medicinal products are being investigated. This study is aimed at investigating the effect of OA on markers of lipid metabolism and on proteins of the insulin signalling pathway in Type 1 diabetic rats as this plant product has anti-hyperglycaemic effects. Male Sprague-Dawley rats were divided into two groups (diabetic and normal). In both groups the rats were further divided into four groups and assigned to treatment as follows: vehicle, insulin, OA and OA plus insulin. Oral glucose tolerance test was performed in fasted and non-fasted diabetic rats for 2 hours. In acute studies the effect OA following treatment of rats was evaluated at 15, 30 and 60 minutes. In sub-chronic studies rats were treated daily for 14 days. OA did not improve glucose tolerance in diabetic rats after 2 hours of administration. However, it enhanced blood glucose lowering effect of insulin and this was statistically significant in fasted rats. In acute studies OA enhanced the effect of insulin in normal and diabetic animals as AKT phosphorylation was increased when insulin was used in combination with OA. OA reduced the expression and activity of HSL in liver tissue after 14 days of treatment in both normal and diabetic rats. In adipose tissue, OA reduced the expression of HSL in diabetic rats. However, OA alone did not reduce the activity of HSL but when it was combined with insulin, a reduction of HSL activity was observed. OA administration had no significant effect on TGA and HDL-c levels but significantly (p < 0.05) reduced total cholesterol and LDL-c in diabetic rats. It had no significant effect on total cholesterol, and increased LDL-c levels in normal rats. Serum AST and ALT levels in diabetic rats were reduced by OA administration but this reduction was not statistically significant. The results of this study suggest that OA enhances the hypoglycaemic effect of insulin, improves lipid profile and possesses hepatoprotective effects. Lastly, OA independently increases AKT phosphorylation and decreases HSL expression and activity. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2013.

<p>Infusions, decoctions, alcoholic preparations and other dosage forms of Artemisia afra are frequently used in South African traditional medicine. Generally when these preparations are made without applying good manufacturing practices they do not meet microbial quality control standards, safety and toxicity criteria and encourage poor patients compliance. To overcome the aforementioned disadvantages of traditional dosage forms a sold dosage form, i.e. a table might be recommended. The first objective of this study was to formulate and manufacture a rapid release tablet dosage of Artemisia afra that would contain an amount of plant material equivalent to that found in its traditional liquid dosage forms and that would meet conventional pharmaceutical standards. The second objective was to conduct a pilot study to obtain a preliminary profile of the bioavailability of select flavonoids presents in both the tablet and traditional liquid preparation of Artemisia afra in humans.</p>

<p>In South Africa, the crude aqueous extract from Hypoxis hemerocallidea is used by AIDS patients to treat opportunistic infections, such as tuberculosis. The rapid emergence of multidrug-resistant tuberculosis, and extreme drug resistant tuberculosis, in recent years, is a major threat to human health. The treatment of TB, nosocomial bacterial infections, and fungal infections is now a clinical challenge, especially in the immuno-compromised individual. There is a dire need for novel antibiotic alternatives with phytotherapies and plant-derived compounds as potentially promising alternatives. The main objective of this study was to investigate the antimycobacterial activity of Hypoxis hemerocallidea, a South African medicinal plant, using Mycobacterium smegmatis.</p>

<p>Early man dabbled with the use of plant extracts to cure ailments. This practice has been passed down from generation to generation and today more than 50% of the world'sdrugs are natural products or derivatives thereof. Scientists have thus established a branch of research called natural product research. This branch of research involves the identification and purification of secondary metabolites with a specific biological activity. The methodology involves the screening of plant products for a specific biological activity, purification of the biologically active natural product by separation technology and structure determination. The biologically active natural products is then further scrutinized to serve as a novel drug or lead compound for the development of a novel drug. This research exploited this research methodology.</p>

<p>The incidence of cardiovascular diseases, including hypertension, is on the increase worldwide. Medicinal plants played an important role in the treatment of hypertension for centuries. Very few scientific studies have, however, been done to validate the use of these phytotherapies. O africana is on of the many phytotherapies that has been use indigenously for years to treat hypertension. The objectives of this study were to determine the most effective does of O africana aqueous extract which will reduce blood pressure / to determine whether chronic administration of O africana can be used to prevent and treat hypertension / to determine whether O africana exert its effects by modulation of the renin-angiotensin system.</p>

Thesis (MSc.(Chemistry)) - University of Pretoria, 2008. / Summary in English. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 81-92) Also available in print.

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 185-217). Also available in print.