Antiradical and Xanthine Oxidase Inhibitory Activity Evaluations of Averrhoa bilimbi L. Leaves and Tentative Identification of Bioactive Constituents through LC-QTOF-MS/MS and Molecular Docking Approach

Abstract

The objective of the present study was to investigate the antiradical and xanthine oxidase inhibitory effects of <i>Averrhoa bilimbi</i> leaves. Hence, crude methanolic leaves extract and its resultant fractions, namely hexane, chloroform, and n-butanol were evaluated for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect and xanthine oxidase inhibitory activity. The active constituents were tentatively identified through LC-QTOF-MS/MS and molecular docking approaches. The n-butanol fraction of <i>A. bilimbi</i> crude methanolic leaves extract displayed significant DPPH radical scavenging effect with IC₅₀ (4.14 ± 0.21 μg/mL) (<i>p</i> < 0.05), as well as xanthine oxidase inhibitory activity with IC₅₀ (64.84 ± 3.93 μg/mL) (<i>p</i> < 0.05). Afzelechin 3-<i>O</i>-alpha-l-rhamnopyranoside and cucumerin A were tentatively identified as possible metabolites that contribute to the antioxidant activity of the n-butanol fraction.