Kumi-Diaka, James

Phytochemicals are biologically active secondary plant metabolites that could mimic biological activities. In this study genistein isoflavone, a phytochemical present in soy was investigated to determine its effect on the growth of human breast cancer cell line GI-101 and normal breast epithelial cells in vitro. The cells were exposed to varying concentrations of genistein isoflavone for 24 and 48 hour time periods and the effect was determined using post-treatment assays: MTT and Trypan Blue for cell viability; LDH assay for cytotoxicity; Rhodamine 123/Propidium Iodide and Ethidium Bromide/Acridine Orange assays for treatment-induced apoptosis and FAM Poly caspase assay for mechanism of action. The overall results revealed that genistein inhibited cell growth and proliferation through apoptosis in the cells in both time and dose-dependent manner. Normal breast epithelial cells were not significantly affected by genistein at the corresponding dosages. Based on the results obtained, it was concluded that genistein isoflavone could offer therapeutic efficacy in human breast carcinoma without significantly affecting the normal breast epithelial cells.

Phytochemicals are biologically active secondary plant metabolites that have been shown to exhibit anti-cancer activity. The dietary phytochemicals genistein isoflavone and beta-lapachone, were investigated to determine their effect on the growth of human prostate adenocarcinoma cells in vitro. The cells were exposed to varying concentrations of both phytochemicals in single and combination treatments for specified time periods and their effect was determined using post-treatment cell viability, treatment-induced apoptosis and cell signaling assays. The overall results revealed that both phytochemicals inhibited cell growth and proliferation and induced apoptosis in a dose-dependent manner for both single and combination treatments. However, combination treatments were not significantly more effective than single treatment with either drug. Both phytochemicals could therefore offer therapeutic efficacy in human prostate adenocarcinoma.

Recent advancement in chemotherapy has resulted in higher and longer survival rates of testicular cancer patients. However the use of chemotherapeutic agents are not without serious, sometimes fatal side effects. This study investigated the potential therapeutic efficacy of pomegranate extracts in testis cancer cells, GC1-spg, in vitro. A battery of assays was used to determine the chemosensitivity of GC1-spg cells to two pomegranate extracts, S (seed) and P (pericarp), in single and combination treatments: MTS and LDH to determine post-treatment survival rate (growth inhibition) and cytotoxicity respectively; Acridine Orange/Ethidium Bromide fluorescent dye to assess treatment-induced apoptosis/necrosis; Annexin V-FITC and TUNEL assays for early and late apoptosis respectively. Results from the obtained data indicated that both extracts have significant cytotoxic effect on testicular cancer cells (GC1-spg) in single and combination treatments. The data revealed a dose and time dependency of chemosensitivity to both extracts; and that apoptosis was the major mechanism treatment-induced cell death. Synergism was also indicated in growth inhibition by combination treatment. These findings offer strong justification for further studies with pomegranate as potential phytotherapy.

The therapeutic potential of pomegranate and genistein on growth inhibition of human breast cancer cells was investigated. Methods. Cells (MCF-7) were initially cultured for 48 hr to achieve 80% confluence; and then exposed to the agents in single and combination treatments. Post-treatment analysis was done by using a series of bioassays, including LDH, MTS, AcrO-EthBr, Annexin-FITC and TUNEL assays for growth inhibition and apoptosis detection; and Caspase-3 and NQO1 for molecular pathways of apoptosis. Results. Pomegranate and genistein showed significant dose- and time-dependent cytotoxic and growth inhibition effects as well as apoptosis induction in MCF-7 cancer cells, with significantly higher ( P < 0.01) effects in the combination treatments than in the single treatments. Both drugs induced apoptosis through a caspase-mediated mechanism and independent of NQO1. Discussion and conclusions. Pomegranate and genistein inhibit the growth of MCF-7 breast cancer cells through induction of apoptosis with combination treatment being more efficacious than single treatments.

The present study was undertaken to determine the chemotherapeutic potential of genistein and beta-lapachone and possible mechanisms of action in prostate cancer in vitro. The bioassays used included: MTT and LDH chemosensitivity-cytotoxicity assays, NQO1 detection, annexin V-FITC, TUNEL and the caspase protease (CPP32) apoptotic detection assays. The results showed that: (i) PC3 cells are sensitive to single and combination treatments in a dose and time dependent manner; (ii) there was treatment-induced dual death pathways (apoptosis and necrosis) with increasing toxicity (necrosis) at higher concentrations in single and combination treatments; (iii) combination treatment was more growth inhibitory than single treatments; (iv) the NQO1 enzyme substantially enhances the toxicity of beta-lapachone but not genistein, while genistein exerted its apoptotic inducing effects via the caspase 3 pathway. The overall results indicate that combination treatments with beta-lapachone and genistein are more efficacious in killing PC3 human prostate cancer cells than treatment with either agent alone.