Cytotoxic effect of Cyperus rotundus rhizome extract on human cancer cell lines

The wild weed Cyperus rotundus is commonly used as traditional medicine in different parts of the world. Sequential extraction of C. rotundus rhizome with solvents of different polarity namely hexane, chloroform, ethyl acetate, methanol and water were prepared and the free radical scavenging activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Based on high antioxidant activity of methanolic extract of C. rotundus rhizome (MRCr) was further investigated for its cytotoxic effect on different human cancer cell lines-breast (MCF-7), cervical (HeLa), liver (Hep G2), prostate (PC-3), colorectal (HT-29) and normal cell line (MCF-12A) by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay evaluated as 50% inhibition of growth (IC50). Apoptosis cells were analysed by flow cytometry stained with annexin V-Fluorescein isothiocyanate conjugate (AF) and propidium iodide (PI). The cellular and nuclear changes were examined under light and fluorescent microscope using 4', 6' diamino-2-phenylindole (DAPI) stain, dual stains of AF/PI and acridine orange/ethidium bromide (AO/EB). The cytotoxic effects on the tested cancer cell lines ranged from 4.52 +/- 0.57 to 9.85 +/- 0.68 mu g ml(-1). The migration assay was showed the inhibitory effect with MRCr. The MRCr showed significant anticancer activity against all the tested cancer cell lines and also protected the non-cancer cells. The anticancer activity suggests further elucidation for the formulation of natural pharmaceutical products in the treatment of cancer.