(394) Antimutagenicity, Antioxidant Activity, and Polyphenolic Contents of Bitter Melon Varieties (Momordica charantia L.)

Abstract

Bitter melon (Momordica charantia L.), an annual vegetable of Cucurbitaceae family, is a vegetable with important nutritional and medicinal qualities. Four adaptable lines/varieties were tested in replicated field trials for productivity, and biochemical and medicinal characteristics at the University of Arkansas at Pine Bluff. The total phenolic contents of the oven-dried and freeze-dried tissues, and seeds, ranged from 5.39–7.75, 6.72–8.02, 6.40–8.90, and 4.67–6.69 mg·g-1 on a dry weight basis, respectively. The total phenolic content of bitter melon from India green (IG), India white (IW), China green (CG) and China white (CW) varieties were 4.67–6.72, 6.03–8.02, 5.39–7.81, and 6.69–8.90 mg·g-1 dry material, respectively. The main phenolic acids in bitter melon flesh were gallic acid, gentisic acid, catechin, chlorogenic acid, and epicatechin. Bitter melon seeds had the phenolic acids, gallic acid, catechin, and epicatechin. The antioxidant activities of methanolic extracts from the bitter melons varieties IG, IW, CG, and CW ranged from 79% to 85%, 79% to 83, 80% to 85, and 79% to 86% inhibition, respectively. The antioxidant activities of the seed ranged from 79% to 84% inhibition. Methanolic extracts of freeze-dried flesh and seed from var. IW and CG showed very high antimutagenic effects against benzo(a)pyrene with Salmonella TA98 (92% to 100% inhibition) TA100 (79% to 86% inhibition), but lower antimutagenicity activities against sodium azide that ranged from 46% to 54% and 17% to 32% inhibition, respectively. The popular belief that bitter melon improves glucose tolerance in Type II diabetes and lowers blood cholesterol is being investigated. It has not been determined which alkaloids, polypeptides, or combination of chemicals found in bitter melon are responsible for the beneficial medicinal effect.