Abstract

There are many reports which show a positive relationship between free radical damage and diseases such as cancer. Free radicals are formed when humans are exposed to ionizing radiation or during oxidation process in human beings can damage tissues and may potentially lead to development of cancers. Since radiation may be used in the management of cancer, there is need for the development of a radioprotective herbal medicine that can be used to increase the therapeutic index of radiotherapy and chemotherapy treatments by offering protection to non cancerous cells. Since most fruits contain polyphenols, they are radical scavengers which can effectively prevent cancer development due to increased reactive oxygen species. The aim of this research was to evaluate how fruit extracts of Annona stenophylla diels and Flacourtia indica may help in the prevention of cancer using UV light induced red blood cell (RBC) haemolysis and1, 1-diphenyl-2-picrylhydrazyl (DPPH) assays. Since cancer pathogenesis may involve lipid peroxidation, UV induced haemolysis and DPPH assays were used to examine the role of the fruit extracts in radioprotection and free radical quenching in order to prevent peroxidation. Phenolic compounds were extracted using aqueous methanol and the two assays were carried out using concentrations ranging from 20 to 200 µg/ml. The results were analysed using T test. The fruit extracts from the two plants showed a marked antioxidant and radioprotection efficacy against lipid peroxidation in the presence of UV light. Both assays showed a significant absorbance inhibition at (p < 0.05) implying that the fruit extracts were effective radical scavengers and radioprotectors. The results obtained suggest that the fruit extracts were good plasma membrane stabilizers and good radical quenchers. The membrane of red blood cells was stabilized by preventing UV induced peroxidation, a process in which free radicals are formed. These findings suggests that fruit extracts obtained from A. stenophylla diels and F.indica plants  can be incorporated in pharmaceuticals formulations as nutraceuticals for prevention cancer and improvement of radiotherapy and chemotherapy therapeutic index.

Key words: DPPH, radioprotective, cancer, UV visble, A. stenophylla diels, F.indica, reactive oxygen species.