Evaluation Of Antibreast And Antiprostate Cancer Activities Of Selected Medicinal Plants From Some Parts Of Kenya

Cancer is a group of diseases characterised by uncontrolled proliferation of cells. Of all the types of cancers worldwide, breast cancer is the most commonly diagnosed in women while prostate cancer is the second in men. The current cancer management methods have challenges including unpleasant side effects, high cost and even not effective. As the number of patients is on the rise, physicians look forward with hope to the discovery and development of safe, effective and less toxic anticancer drugs. More than 67 % of prescribed anticancer drugs have been developed based on natural products. The objective of this study was to evaluate anticancer activities of extracts obtained from Fagaropsis angolensis, Hydnora abyssinica, Launaea cornuta, Spermacoce princeae, Combretum tanaense, Uvariodendron anisatum, Marsidenia schimperi and Prunus africana against breast and prostate cancer cells. Methanol and water extracts from the seven plants were evaluated for anticancer activities using methyl thiazole tetrazolium cell viability (MTT) assay and microtiter 96 well plates. Breast cancer (HCC 1395 and 4T1) and prostate cancer (DU-145 and 22RV1) cell lines were used in this study. The contols that were used in this study were cyclophosphamide and fluorouracil for positive chemotherapeutic agent and African green monkey kidney epithelia normal cell (vero) for for cancer cells. Enzyme linked immunosorbent assay (ELISA) scanning multiwell spectrophotometer was used to measure optical densities to calculate cell viability. Analysis of concentrations that inhibited 50% of cell growth (IC50) was done using Prism Graphpad version 8.0. Remarkable activities of extracts (IC50 < 50 µg/ml) were demonstrated by the methanol extracts of C. tanaense root, U. anisatum root, H. abyssinica rhizome, M. schimperi husks, M. schimperi leaves and F. angolensis stem bark. High selectivity indices were revealed F. angolensis extrcats. Bioassay-guided isolation of these extracts resulted to isolation of seven compounds. The active fractions were those F. angolensis and C. tanaense extracts, dichloromethane and ethyl acetate fractions, respectively, the two fractions exhibited anticancer activities with moderate (1 ≤ SI ≤3)  to high (SI > 3) selectivity indices. The isolated compounds were coded as FC1, FC2, FC3, CC1, CC2, UC1 and UC2. The FC1-3 compunds were active against cancer cell lines, CC1-2 revealed moderate activities and UC1-2 were not active. FC1 revealed high selectivity indices against the cancer cell lines. All extracts that demonstrated remarkable anticancer activities revealed no toxic effects upon acute oral toxicity studies on swiss mice. It was therefore established that plants that were selected on the basis of ethnopharmacological approach had potential anticancer activities and were also relatively safe. Moreover, the compounds that were isolated were remarkably active and less toxic. This study therefore provided scientific basis for validating the use of extracts from Fagaropsis angolensis stem bark and Hydnora abyssinica rhizome in the management and treatment of breast and prostate cancers.