IN VITRO EVALUATION OF ANTIOXIDANT AND ANTIDIABETIC POTENTIAL OF THE EXTRACTS FROM Miliusa velutina LEAVES

Abstract

This study evaluated the in vitro inhibitory effects of different extracts of the Miliusa velutina leaf on the activities of diabetes-related enzymes (α-amylase and α-glucosidase) and chemically induced free radicals. The ethanol, n-hexane, dichloromethane, ethyl acetate and aqueous extracts of Miliusa velutina leaves were subjected to a standard enzyme inhibition assay followed by determination of modes of inhibition of the enzymes. The antioxidant activities of the extracts were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), reducing power (RP) assays. The results obtained showed that the aqueous extract of the Miliusa velutina leaves optimally inhibited both α-amylase (IC₅₀=260.46±6.61µg/mL) and α-glucosidase (IC₅₀=14.81±0.58 µg/mL). Beside, the aqueous extract displayed the best DPPH, ABTS, TAC, RP and FRAP radical-scavenging ability, respectively. Results demonstrated that Miliusa velutina leaf extracts can represent an important natural source with high antioxidant potential and significant α-amylase and α-glucosidase inhibitory effects.