Antioxidant potential and type II diabetes-related enzyme inhibition of Cassia Obtusifolia L.: effect of indigenous processing methods

Abstract

The methanolic extract of Cassia obtusifolia L. (Sicklepod) seed, an underutilized food legume from India, was analyzed for antioxidant and health relevant functionality. The total free phenolic content of the raw seeds was 13.33 ± 1.73 g catechin equivalent/100 g extract. The extract exhibited 1,292 mmol Fe[II] per milligram extract of ferric reducing/antioxidant power, 49.92% inhibition of ß-carotene degradation, 65.79% of scavenging activity against DPPH, and 50.78% of superoxide radicals. The in vitro starch digestion bioassay of the extract showed 79.80% of α-amylase and 81.04% of α-glucosidase enzyme inhibition characteristics. Sprouting + oil frying caused an apparent increase on the total free phenolic content with significant improvement on the antioxidant and free radical scavenging capacity of C. obtusifolia seeds, while soaking + cooking as well as open-pan roasting treatments show diminishing effects. Inhibition of α-amylase and α-glucosidase enzyme activity was 23.81% and 42.36%, respectively, following sprouting + oil-frying treatment. These enzyme inhibition values were similar to that of synthetic antidiabetic agent acarbose.