Sutherlandia frutescens (SF), an indigenous medicinal plant to South Africa (SA), is traditionally used to treat a diverse range of illnesses including cancer and viral infections. The biologically active compounds of SF are polar, thus renal elimination increases susceptibility to toxicity. This study investigated the antioxidant potential, lipid peroxidation, mitochondrial membrane potential and apoptotic induction by SF on proximal and distal tubule epithelial cells. Cell viability was determined using the MTT assay. Mitochondrial membrane potential was determined using a flow cytometric JC-1 Mitoscreen assay. Cellular glutathione and apoptosis were measured using the GSH-GloTM Glutathione assay and Caspase-Glo® 3/7 assay, respectively. The IC50 values from the cell viability results for LLC-PK1 and MDBK was 15 mg/ml and 7 mg/ml, respectively. SF significantly decreased intracellular GSH in LLC-PK1 (p < 0.0001) and MDBK (p < 0.0001) cells. Lipid peroxidation increased in LLC-PK1 (p < 0.0001) and MDBK (p < 0.0001) cells. JC-1 analysis showed that SF promoted mitochondrial membrane depolarization in both LLC-PK1 and MDBK cells up to 80% (p < 0.0001). The activity of caspase 3/7 increased both LLC-PK1 (11.9-fold; p < 0.0001) and MDBK (2.2-fold; p < 0.0001) cells. SF at high concentrations plays a role in increased oxidative stress, altered mitochondrial membrane integrity and promoting apoptosis in renal tubule epithelia. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

Ochratoxin A (OTA), a nephrotoxic mycotoxin, is a contaminant of several agricultural food products consumed by animals and humans. Apart from renal toxicity, in particular renal tumours, OTA may also result in teratogenicity, neurotoxicity and immunotoxicity. Sutherlandia frutescens, an indigenous medicinal plant, has shown significant potential in strengthening the immune system and in cancer treatment, with minimal side effects. The objective of this study was to determine the effects of OTA in male Wistar rats and ascertain if these effects may be reduced by S. frutescens. Rats were treated by intraperitoneal injection (i.p) with either a control (EtOH:dH20;30:70), S. frutescens (1.0mg/kg body weight), OTA (0.5mg/kg body weight) or a combination of OTA and S. frutescens for a period of 1 or 7 days (n=4). Genotoxicity and metabolic activity in peripheral blood mononuclear cells (PBMCs) were quantified using single cell gel electrophoresis (SCGE) and the methylthiazol tetrazolium (MTT) assay, respectively. Lymphocyte apoptosis and mitochondrial depolarisation were measured by flow cytometry. Fluorescence microscopy was utilised to determine renal tissue apoptosis (Hoechst staining) and OTA localisation using immunohistochemistry (IRC). SDS-PAGE and Western blot were utilised to determine protein expression in kidney tissue and serum. Ochratoxin A significantly reduced PBMC viability (14%) after 7 days, compared with Day 1 (p<0.001). Lymphocyte mitochondrial depolarisation was 56.5% and 66.2% in the OTA-only and combination groups, respectively after 7 days (p<0.001). Ochratoxin A produced an increase in DNA damage compared to the control (p<0.01). The renal tissue displayed typical signs of apoptosis such as chromatin condensation. Ochratoxin A was immunolocalised within the glomerulus. The protein analysis showed a decreased expression in the kidney mitochondrial protein fraction. Ochratoxin A preferentially bound to serum albumin and a 120kDa protein in the OTA-only and co-treatment groups after the 1-and 7-day regimes. Protein band intensities significantly decreased after the 7-day co-treatment (p<0.01). The data highlights that OTA toxicity is mediated by mitochondrial dysfunction. Furthermore, OTA disruptions in immune function may play a role in renal damage. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Westville, 2009.

Background and Aims of Study. Scilla nervosa is a member of the Hyacinthaceae plant family that has been naturalised in the grasslands of Southern Africa. The bulbs are traditionally used to treat a variety of ailments. For example, the Zulu people use aqueous decoctions of the bulbs as analgesics in the treatment of rheumatic fever, crushed bulbs are used by the Sotho people as laxatives and the Tswana people use cooked bulbs to treat infertility in women as well as cold aqueous extracts to treat infections. It was recently demonstrated in our laboratory that extracts prepared from the bulbs possess potent anti-inflammatory properties, and this may therefore provide a rationale for the traditional use of the plant as an analgesic. Several studies have demonstrated that the bulbs contain homoisoflavanones and stilbenoids that could be responsible for their therapeutic effects. Although the plant has diverse medicinal applications, and despite it being recognised as a poisonous species particularly in livestock, little is known about its toxicity in human liver cells. The objectives of this study were therefore to investigate the potential toxicity of the bulbs on the liver, a major detoxifying organ. A human liver cell line was treated with an aqueous extract of the bulbs to investigate (1) cell viability, (2) potential mechanisms of cytotoxicity, (3) DNA integrity, and (4) changes in the cytochrome P450 enzyme activity. Materials and Methods. This study was conducted on the cultured HepG2 human hepatocellular carcinoma cell line, a model system to investigate the cytotoxicity of xenobiotics. The viability of cultured HepG2 liver cells in the presence of varying concentrations of an aqueous extract of the bulbs was determined after 24 hours treatment, and the concentration that reduced viability to 50% (IC50) was derived. Potential mechanisms of cytotoxicity at the IC50 were investigated. These included changes in metabolic activity (intracellular adenosine triphosphate (ATP) quantification), apoptosis induction (phosphatidylserine (PS) externalisation, caspase-8 and -9 induction and changes in mitochondrial membrane potential), and oxidative damage via free radical formation (lipid peroxidation). Genotoxicity was investigated by determining changes in DNA integrity (DNA fragmentation). The ability of the extract to stimulate or {¹ Du Toit, K., Kweyama, A., Bodenstein, J. 2011. Anti-inflammatory and antimicrobial profiles of Scilla nervosa (Burch.) Jessop (Hyacinthaceae). South African Journal of Science, 107:96-100.} inhibit enzymes commonly involved with drug metabolism was investigated by determining cytochrome P450 3A4 (CYP3A4) activity. Results Cell-viability decreased in a concentration-dependent manner and the IC50 was determined as 0.03 mg/ml. Treating the cells at the IC50 resulted in (1) a 1.2-fold increase in intracellular ATP levels, (2) no significant change in PS externalisation, (3) a 1.3-fold increase in caspase-8 activity, (4) a 1.1-fold decrease in caspase-9 activity, (5) no significant change in mitochondrial membrane potential, (6) a 1.9-fold increase in lipid peroxidation, (7) evidence for genotoxicity as demonstrated by DNA fragmentation, and (8) no evidence of changes in CYP3A4 activity. Conclusion. Results suggest that HepG2 liver cells are sensitive to an aqueous extract of the bulbs of S. nervosa. The extract has the potential to (1) induce apoptosis, (2) increase oxidative stress and (3) cause genotoxicity in vitro. peroxidation, genotoxicity / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.

Some species of sundew (Drosera spp.), harvested from the wild for use in homeopathic cold remedies, are now endangered. This research consisted of two experiments in hydroponic production of sundew. The first investigated the effects of four nitrogen (N) fertilization levels (0.0, 5.1, 25.5 or 51.0 mg/L added N) and three harvest methods (after two months, four months, and sequential harvest at two and four months) on the growth of Drosera adelae (F. Muell.). In addition, the effect of N on the production of a medicinal active ingredient in D. adelae was examined. The second experiment investigated effects of the same nitrogen treatments in combination with three substrates (long fiber sphagnum, peat or rockwool) on growth. The growth rate of D. adelae was greatest at low levels of nitrogen fertilization, and slowed after two months of growth. Plants that were sequentially harvested had the lowest growth rate among all the harvest method treatments. Young plants and plants that received little or no N fertilizer had a greater water concentration than the other plants. Substrate and N level interacted, but generally peat and rockwool produced greater yields than did sphagnum. The medicinal compound plumbagin and a similar but unidentified compound were detected in the leaf extracts of D. adelae. However, whether N fertilization influenced the concentration of these compounds remains inconclusive.

Abstract available on PDF file. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2013.

This study aimed to evaluate the antimicrobial efficacy of medicinal hemp plant extracts to determine the antibacterial effects of indigenous Sansevieria species and exotic Cannabis sativa phytotherapy varieties. This study also assessed whether aqueous o

<p>Since Helichrysum is known by the indigenous people of Africa for therapeutic properties, such as against colds, flu and wounds, the aim of this study was to focus on the patulum species found predominantly in the Western Cape region of South Africa and by means of isolation and identification of the plant constituents, be able to relate the therapeutic activity on the basis of literature precedents, to the compounds extracted.</p>

Thesis (PhD (Phytomedicine, Paraclinical Sciences))--University of Pretoria, 2007. / Includes bibliographical references.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 78-82). Also available in electronic version.

Thesis (MSc (Phytomedicine, Paraclinical Sciences))--University of Pretoria, 2007. / Includes bibliographical references.