Evaluation of the Anticancer Potential of Medicinal Plant Extracts Against Colorectal Cancer: A study on Croton megalocarpus, Terminalia brownii, Prunus africana, and Warburgia ugandensis

Colorectal Cancer (CRC) is globally prevalent, ranking second in mortality (9.3%) and third in incidence (9.6%). Chemotherapy has significant side effects, necessitating alternative treatments. Historically, medicinal plants and natural products have been of interest. This study investigates the anticancer activity of various plant extracts: ethanolic extract of Croton megalocarpus leaves, Terminalia brownii bark, ethyl acetate extract of Prunus africana bark, and chloroform and acetone extracts of Warburgia ugandensis bark on a colon adenocarcinoma cell line. Additionally, the study also explores mechanistic cell death pathways (apoptosis or necrosis). Cytotoxic effects using a neutral red (NR) uptake assay was assessed on a colon adenocarcinoma cell line. DNA Damage characterized using the Alkaline comet assay. Cytotoxicity and Plasma Membrane Damage evaluated using the lactate dehydrogenase (LDH) Leakage Assay. Mechanistic Pathways explored by measuring mRNA expression levels to distinguish between intrinsic and extrinsic apoptosis pathways (P53, Bax, Bcl-2, Bcl-xl for mitochondrial pathway; caspase-8 for extrinsic pathway; caspase-3 for apoptosis activity; survivin as a marker for apoptosis). IC50 values determined for the extracts: C. megalocarpus leaves (45.5 µg/ml), T. brownii bark (41 µg/ml), P. africana bark (70.2 µg/ml), and W. ugandensis bark (4.4 µg/ml for chloroform, 20.7 µg/ml for acetone). Apoptosis: Induced in all treatments except for C. megalocarpus leaves ethanol extract due to a significant decrease in survivin expression.