Cytotoxic effect of Moringa oleifera on colon cancer cell lines

Herbal medicines are gaining interest in current research to treat diverse diseases caused by both viral and bacterial agents. Many were shown to be effective as antimicrobial, anticancer, anti-inflammatory, antidiabetic, and to have antioxidant effects. The effect of Moringa oleifera on these ailments was investigated by others. The anti-tumor effect of M. oleifera was studied on breast and lung cancer cells. In this study, we examine its cytotoxic effect on colon cancer cells and determine its mode of action. Three colon cancer cell lines (HCT116, CACO2, and HCT116P53-/-) were used. Different percentages of leaf extract ranging from 0.1 to 2.5% were prepared in boiling water. The cytotoxic effect of the extracts was tested on three colon cancer cell lines (HCT116, CACO2, and HCT116P53-/-) by MTT assay. Membrane integrity was assessed by lactate dehydrogenase release. ROS level was estimated following the conversion of Nitrobluetetrazolium salt into blue formazan. DNA content was quantified using Propidium Iodide (PI) stain and flow cytometry. Water extracts of M. oleifera leaves decreased the viability of colon cells in a concentration-dependent manner. IC50 obtained ranged between 0.02 to 0.05% for the three cell lines. Treatment of HCT116, Caco2, and HCT116P53-/-with extract at the IC50 induced ROS production and caused LDH release. All three cell lines were arrested at sub G0 phase. Extracts induced cell death mediated by an increase in oxidative stress, disruption of membrane integrity and cell cycle arrest in subG0 phase.