An investigation into the bioactivity of Sutherlandia frutescens (Cancer bush)
Thesis (MSc (Biochemistry))--University of Stellenbosch, 2009.
Sutherlandia frutescens (S. frutescens), sub-species microphylla, is a member of the Fabacea family and is used as a herbal remedy for the treatment of several ailments which include influenza, diabetes, cancer, tuberculosis, chronic fatigue syndrome, rheumatoid arthritis, anxiety, clinical depression, and more recently, those living with human immunodeficiency virus/ acquired immune deficiency syndrome (HIV/AIDS) (1-4). Many of the symptoms of these ailments are associated with a perturbation of the stress response which may be associated with disorders of the endocrine system. Of all the traditional plants in South Africa, S. frutescens is regarded the most profound in that it is a multipurpose traditional remedy. The plant has enjoyed a long history of use and reports indicating its efficacy as a safe treatment for various health conditions have added to the popularity of this medicinal plant. The extracts of S. frutescens have been shown to exhibit anti-proliferative effects on cancer cells, antioxidant activity, and to possess anti-diabetic and anti-inflammatory potential (5, 6), providing scientific evidence for its therapeutic use in the treatment of cancer and diabetes. However, this study focuses on the potential use of this medicinal plant in the treatment of stress and stress related diseases. Chronic stress is characterized by elevated plasma levels of glucocorticoids. These steroid hormones are synthesized in the adrenal cortex in a series of reactions involving the steroidogenic enzymes. The major aim of this thesis was the determination of the influence of S. frutescens extracts on the adrenal cytochrome P450 enzymes. Aqueous, methanol and chloroform S. frutescens extracts were prepared and the interaction with the cytochrome P450 enzymes was investigated. The effect of these extracts towards progesterone (PROG), deoxycortisol and deoxycorticosterone (DOC) binding to the cytochrome P450 enzymes as well as their influence on the metabolism of these steroid substrates was investigated. A similar study (7) showed that compounds from the S. frutescens extracts could interact with these enzymes and possibly affect adrenal steroidogenesis. This study further investigates the bioactive properties of the plant material in terms of the influence of S. frutescens on the cytochrome P450 enzymes and the effect of the manufacturing process on the bioactivity of the plant.