Effect of extraction solvents on the phytochemical content and bioactivity of Momordica charantia Linn. fruits

Abstract

Momordica charantia (M. charantia) is a herbaceous climber commonly found in Southeast Asia with therapeutic importance for various illnesses. This study focused on the effect of extraction solvents on saponins-containing compounds from M. charantia and their bioactivities. Different organic solvents including water, ethanol, ethyl acetate, a mixture of methanol-water and methanol-n-butanol were used in the extraction process. The total saponin content, total flavonoid and phenolic content for each extract were examined. In addition, the antioxidant capacity of these extracts were evaluated using both 1,1-diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity and 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay. Furthermore, a-amylase and lipase inhibition assay were carried out using an in vitro model. The result showed that methanol-n-butanol extracts exhibited the highest total saponin, flavonoid, phenolic content, and ABTS antioxidant activity compared to the other extracts. The a-amylase inhibition assay revealed that water extract and methanol-n-butanol extract from M. charantia contained potent a-amylase inhibitor. On the other hand, the ethyl acetate extract was found to have the most antioxidant capacities based on DPPH radical scavenging assay. The ethyl acetate extract also exhibited the highest inhibition of lipase activities. In conclusion, the methanol-n-butanol solvent was found to be the most effective in extracting saponin from M. charantia. The M. charantia extracts showed inhibition of a-amylase and lipase activities which may suggest the therapeutic potential of M. charantia for obesity and diabetes.