Abstract:
Diabetes mellitus is a serious metabolic disorder characterized by
hyperglycemia. One holistic approach to control the hyperglycemia condition is
to partially inhibit the carbohydrate hydrolyzing enzymes during digestion of
food. In this study, anti-hyperglycemic and anti-oxidative potentials of the bran
extracts of rice (Oryza sativa L.) and some selected beans (red bean, red kidney
bean and white bean) (Phaseolus vulgaris L.) obtained with 80% ethanol-water
mixture were compared. The total phenolic content, the α-amylase and α glucosidase inhibitory potentials, ferric reducing antioxidant power (FRAP), 2,2'-
azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging
activity and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging
activity of the extracts were studied in vitro using the relevant assays. Results
showed that red bean bran extract contained the highest phenolic content (0.122
mg of Gallic Acid Equivalent/g of extract). The mean of the FRAP values of the
extracts were ranged from 48.98 to 75.94 µmol FeSO4/g of bran extract. Bran
extract of red kidney bean displayed the highest ferric reducing power (75.94
µmol FeSO4/g) compared to any other bran extracts. Bran extract of rice
displayed the highest inhibitory effect against the α-amylase activity (96.18%)
while bran extract of red bean showed the highest inhibitory effect against the α glucosidase activity (39.57%). This study concluded that the bran extracts of rice
and the selected beans were potent sources of natural antioxidants and good
postprandial hyperglycemia regulators.
