In vitro Cytotoxic and Antioxidant Activity of Leaf Extracts of Mangrove Plant, Phoenix paludosa Roxb

Purpose: To investigate the anti-proliferative and antioxidant potentials of four different solvent extracts of Phoenix paludosa Roxb leaves. Methods: Four different solvent (hexane, chloroform, ethyl acetate and methanol) leaf extracts of the plant were tested for cytotoxicity against four cancer cells, viz, MCF-7 (oestrogen positive breast cancer cell line), MDA-MB-231 (triple negative breast cancer cell line), SK-BR-3 (breast adenocarcinoma) and ACHN (renal adenocarcinoma) as well as two normal cell lines, namely, HEK-293 (embryonic kidney cells) and MCF-10A (normal mammary epithelial cells)]. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2, 29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging assays were used to evaluate the antioxidant activity of the crude extracts. Results: The methanol extract showed the highest antioxidant activity (DPPH, half maximal inhibitory concentration (IC50) = 30.17 +/- 6.21 mu g/mL)and (ABTS, IC50 = 27.91 +/- 3.21 mu g/mL). Of the four extracts, methanol extract showed the strongest significant (p < 0.05) cytotoxicity to all four cancer cell lines at 24 and 48 h of incubation followed by the chloroform extract (IC50 of methanol extract (24 and 48 h): 36.71 +/- 8.72 and 33.19 +/- 5.53 mu g/mL (MCF-7), 159.7 +/- 32.09 and 141.9 +/- 26.2 mu g/mL (MDA-MB-231), 103.3 +/- 18.9 and 75.39 +/- 19.39 mu g/mL (SKBR-3), 57.21 +/- 3.72 and 43.16 +/- 10.25 mu g/mL (MCF-10A), 37.48 +/- 5.75 and 26.99 +/- 1.85 (ACHN) and 66.83 +/- 14.26 and 60.34 +/- 10.66 mu g/mL (HEK-293)). Furthermore, the methanol extract was least cytotoxic to normal cell lines. Conclusion: The results obtained indicate that the methanol leaf extract of P. paludosa exhibit potent antioxidant and cytotoxic activities and has the potential of being developed into an anti-cancer agent.