Assessment of in vitro antioxidant and antidiabetic capacities of medlar (Mespilus germanica)

Abstract

The objective of the current study was to evaluate the antioxidant activity and enzyme inhibitory effect of different parts of medlar including fruit, leaf and flower bud by using various in vitro methods, and also determination of total phenolic and flavonoid content in the samples. Ethanol extracts of medlar parts were prepared and their antioxidant activities were determined using 1,1-diphenyl-2-picryl-hydrazil (DPPH•) scavenging and β-carotene bleaching methods. The leaf extract showed the strongest antioxidant activity. DPPH radical scavenging activity was in the order of BHA > leaf > bud > fruit. This ordering was the same for β-carotene bleaching activity, tocopherol > leaf > bud > fruit. The highest total phenolic (60.3 ± 1.69 mg GAE g-1 extract) and flavonoid (14.77 ± 1.15 mg QE g-1 extract) content were determined in leaf extract. For possible antidiabetic effects of extracts, α-amylase and α-glucosidase inhibitory activities were investigated, the bud extract showed the highest inhibition activities among the all extracts.