Induction of Apoptosis in Human Colon Cancer Cells by Methanol Fraction of Leaves of Plectranthus amboinicus (Lour) Spreng

To evaluate the cytotoxicity and apoptosis inducing activities of the methanol extract from leaves of Plectranthus amboinicus (Lour) Spreng in an attempt to determine whether the medicinal uses are supported by pharmacological effects. Cytotoxicity was determined by sulforhodamine B assay method. Cytotoxicity and apoptosis inducing effect were evaluated in- vitro using human colon cancer cell line, COLO 205. There was statistically significant cell growth inhibition at the doses of 10, 20, 40 and 80 μg/ml methanol extract of Plectranthus amboinicus (Lour) Spreng. Similarly, Plectranthus amboinicus at the doses of 50 and 100 μg/ml induced apoptosis in COLO 205 cells. The results suggest that the methanol extract of Plectranthus amboinicus (Lour) Spreng possesses anti- proliferative and apoptosis inducing activities, supporting the folk use of this medicinal species.