EVALUATION OF THE ANTICANCER POTENTIALS OF Senna alata LEAF AND Khaya senegalensis STEM BARK EXTRACTS ON COLORECTAL CANCER CELL LINE

Abstract

Colorectal cancer (CRC), also known as bowel cancer, colon cancer or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. The risk of developing this cancer is related to bad alimentary habits, smoking, intestinal inflammatory disease, polyps, genetic factors, and aging. The aim of this research was to evaluate the anticancer potentials of Senna alata leaf and Khaya senegalensis stem bark extracts using colorectal cancer cell line. The quantitative phytochemical composition of the crude methanol extracts of Senna alata and Khaya senegalensis stem bark was determined using standard methods. The partitioning of the crude methanol extract of Senna alata was carried out using n-hexane, ethyl acetate and aqueous. Preliminary cytotoxic activity screening was carried out using the brine shrimp lethality test, while the cytotoxic activity was evaluated using CellTiter Glo® 2.0 assay kit on Colorectal Cancer cell line. The cytotoxic activity of ethyl acetate fraction on Colorectal Cancer cell line was treated at doses 50, 100, 250, 500 and 1000 µg/ml for 24hrs and 48hrs. The phytochemical compositions of the crude methanol extract of Senna alata shows the presence of Phenols (397.70±1.01), Flavonoids (138.56±0.09) Tannins (43.13±0.23), Alkaloids (185.09±0.33) and Saponins (282.50±1.62) whereas the The phytochemical compositions of the crude methanol extract of Khaya Senegalensis shows the presence of Phenols (403.58±1.04), Flavonoids (136.7±0.06) Tannins (75.10±0.14), Alkaloids (229.84±0.59) and Saponins (166.38±1.24). The acute oral toxicity test of the plant extracts shows no toxicological effect on all the tested rats and the lethal dose (LD50) was recorded to be greater than 5000mg/kg. The cytotoxic effect of the crude methanol extract of Senna alata on brine shrimp show higher activity with significant lethal concentration (LC50) 17.87ppm than Khaya senegalensis with lethal concentration 30.975ppm. The Brine shrimp lethality assay revealed that, the ethyl acetate fraction with lethal concentration (LC50) of 1.308ppm exhibited higher cytotoxic activity than other fractions with lethal concentration of 6.172ppm (n-hexane) and 57.805ppm (aqueous). The ethyl acetate fraction exhibited cytotoxicity towards human colorectal cancer cell line by 82% with an inhibitory concentration (IC50) of 324.19µg/ml after 24hrs of exposure and 93% inhibition with an IC50 of 91.52µg/ml after 48hrs of exposure at doses 1000µg/ml. Results of adenosine triphosphate (ATP) assay showed high and dose-dependent inhibition of human colorectal adenocarcinoma (HT-29) cell-line growth by ethyl acetate fraction of Senna alata extract. The ethyl acetate fraction of Senna alata extract caused a significant decrease in proliferation of Colorectal Cancer cell line and thus, could serve as a source of potential candidate drug to manage Colorectal Cancer.