Gene Expression Mediated Antiproliferative Potential and Safety of Selected Medicinal Plants Against Cancerous and Normal Cells

Globally, approximately 13% of all deaths annually are attributed to cancer. Surgery, radiation and chemotherapy are the current treatment techniques for cancer, however these methods are expensive, have high failure rates and have been associated with detrimental side effects. Plant derived products could be good candidates in alleviating challenges being experienced with these current methods. This study aimed at evaluating the phytochemistry, antiproliferation potential, and probable mechanism of action of Albizia gummifera, Rhamnus staddo and Senna didymobotrya plant extracts. Phytochemical screening was done as per standard procedures. The common 3– (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium (MTT) dye was used in the determination of the antiproliferative activity of the extracts. Extracts induction of VEGF (angiogenesis) and p53 (apoptosis) genes9 expression was evaluated using Real Time Polymerase Chain Reaction. Phytochemical screening revealed presence of alkaloids, tannins, glycosides, flavonoids, terpenes, phenolics and saponins in the plants extracts. A. gummifera9s stem bark methanol: dichloromethane extract had the highest activity against the cancerous cell lines tested: HCC1395 (IC50 6.07±0.04µg/ml), DU145 (IC50 3.34±0.05µg/ml), CT26 (IC50 5.78±0.08µg/ml) and Hep2 (IC50 7.02±0.01µg/ml). R. staddo root bark methanol: dichloromethane extract had an IC50 value of 15.71±0.04µg/ml on HCC, 9.81±0.09µg/ml on Hep2 and 11.14±0.39µg/ml on CT26. S. didymobotrya root bark methanol: dichloromethane extract inhibited HCC with an IC50 of 65.06±0.07µg/ml, CT26 with an IC50 of 15.71±0.04µg/ml and Hep2 with an IC50 of 62.10±0.11µg/ml. From the results obtained, the plants exhibited selective toxicity to cancer cells while sparing the normal cells (SI ≥ 3). A. gummifera and S. didymobotrya and R. staddo plant extracts upregulated p53 and down-regulated VEGF genes. In conclusion, this study confirms that these plant extracts could be potential candidates for development of drugs for the management of breast, prostrate, colorectal and throat cancer.