Free radical scavenging and cytotoxic effects of methanol extract of Theobroma cacao L. (Sterculiaceae) seed

Background: Theobroma cacao L. (Sterculiaceae) is a plant with great economic and health benefits. The plant is believed to possess diverse medicinal value among different populations.

Objective: The present study determined the radical scavenging and cytotoxic activities of the methanol seed extract of Theobroma cacao and its fractions.

Methods: Total phenolic, flavonoid content and the 2,2-diphenyl-2-picryl-hydrazyl (DPPH) radical spectrophotometric assays were used to determine the antioxidant potential of the T. cacao seed extracts. Cytotoxicity activity of the extracts was determined using the MTS assay against MCF-7 breast cancer cell lines.

Results: The seed extracts showed remarkably high scavenging effect on DPPH radical. The ethyl acetate fraction exhibited the highest scavenging effect with IC50 value of 5.00 µg/mL. The phenolic and flavonoid contents were significantly higher in the ethyl acetate fraction compared to other fractions (p < 0.05). The MTS assay revealed about 17.90 % and 22.00 % reduction in MCF-7 viability after 48 h exposure to 50 µg/ml of the crude methanol extract and the petroleum ether fraction respectively.

Conclusion: The above results illustrate the antioxidant ability of cocoa seed and show its potential cytotoxic effect on breast cancer cell line. This finding however needs substantiation by further experiments.