Phenolic Antioxidants in Some Vigna Species of Legumes and their Distinct Inhibitory Effects on α‐Glucosidase and Pancreatic Lipase Activities

Abstract

Phenolic extracts of 4 Vigna species of legumes (mung bean, moth bean, and black and red varieties of adzuki beans) were evaluated for phenolic contents, antioxidant activities, and inhibitory properties against α‐glucosidase and pancreatic lipase. Results showed that adzuki bean varieties contain higher phenolic indexes than mung bean and moth beans. Adzuki bean (black) variety was found to be the most active 2,2´‐diphenyl‐1‐picrylhydrazyl and superoxide anion scavenger. However, the hydrogen peroxide scavenging and metal chelating abilities were significantly higher in adzuki bean (red) variety. Mung bean exhibited least antioxidant activities in all the methods tested. Phenolic extracts from these legumes also showed distinct variations in the inhibition of enzymes associated with hyperglycemia and hyperlipidemia. Inhibitory activities of all the extracts against lipase were found to be more potent than α‐glucosidase. Although, α‐glucosidase inhibitory activity was superior in the black variety of adzuki bean (IC50, 26.28 mg/mL), both adzuki bean varieties (black and red) along with moth bean showed strong inhibitory activities on lipase with no significant difference in their IC50 values (7.32 to 9.85 mg/mL). These results suggest that Vigna species of legumes are potential source of antioxidant phenolics and also great sources of strong natural inhibitors for α‐glucosidase and lipase activities. This information may help for effective utilization of these legumes as functional food ingredients for promoting health. Practical Application: Vigna species of legumes are good sources of phenolic antioxidants and strong natural inhibitors of enzymes associated with diabetes and obesity. Therefore, utilization of these legumes in the development of functional foods with increased therapeutic value would be a significant step toward health promotion and wellness.

Screening of lipase inhibitors from Scutellaria baicalensis extract using lipase immobilized on magnetic nanoparticles and study on the inhibitory mechanism

“…Obesity is primarily caused by the disorder of lipid metabolism, and lipase inhibitors can inhibit the absorption of dietary triglyceride to prevent obesity [12,13]. Since most herbal plants exhibit multiple pharmaceutical effects through multiple targets [14,15], it is of great interest to find out if S. baicalensis contains lipase inhibitors in addition to α-glucosidase inhibitors. To the best of our knowledge, no relevant studies have been carried out so far.…”

Inhibitory Effects of Phenolics and Saponins From Commonly Consumed Food Legumes in China Against Digestive Enzymes Pancreatic Lipase andα-Glycosidase

“…It was reported that total phenolics extracted from mung bean inhibited 17.7% of pancreatic lipase activity, and that from adzuki bean inhibited 9.85% of pancreatic lipase activity. [22] The reasons for the different data from the authors' may owe to the different extraction methods.…”

“…Reflux extraction at 55℃ with 80% aqueous methanol containing 1% HCl (1:50, w/v) was used to extract for 1 hr by Sreerama et al [22] The extraction time was too short and the post-treatment was omitted, which might affect their inhibitory effects against pancreatic lipase activity.…”

Flour functionality and nutritional characteristics of different roller milled streams of foxtail millet (Setaria italica)

“…Determination of antioxidant activity 2.9.1. Total antioxidant activity Total phenolics from defatted millets fractions were extracted according to the method of Sreerama, Takahashi, and Yamaki (2012). Samples were extracted with 80% aqueous methanol containing 1% HCl (1:50, w/v) under reflux in a water bath at 55 C for 1 h. The suspension was centrifuged and extraction was repeated 2 more times.…”