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 Averrhoa bilimbi 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 A. bilimbi crude methanolic leaves extract displayed significant DPPH radical scavenging effect with IC50 (4.14 ± 0.21 μg/mL) (p < 0.05), as well as xanthine oxidase inhibitory activity with IC50 (64.84 ± 3.93 μg/mL) (p < 0.05). Afzelechin 3-O-alpha-l-rhamnopyranoside and cucumerin A were tentatively identified as possible metabolites that contribute to the antioxidant activity of the n-butanol fraction.

Antioxidant Activity in Rheum emodi Wall (Himalayan Rhubarb)

“…Therefore, it has been concentrated on the use of therapeutic natural products to screen for more effective antioxidant agents, as well as to elucidate the mechanisms of free radical prevention. Oriental medicinal plants have been of particular interest as a source of new agents, due to their variety in species and use as traditional medicines for many decades in Asia [ 20 , 21 , 22 ].…”

Antioxidant Activity of Polyphenolic Plant Extracts

“…Interestingly, it was also demonstrated for the first time that the exocarp of D. indum fruit contains thirteen phenolic antioxidants (i.e., vanillic acid, syringic acid, ferulic acid, isoferulic acid, sinapic acid, vanillin, syringic aldehyde, p-hydroxybenzaldehyde, coniferyl aldehyde, p-hydroxybenzoic acid, homovanillic acid, p-coumaric acid, and sinapic aldehyde) [32]. Averrhoa bilimbi is another plant that has been used in traditional medicine of Asian countries [33]. Ahmed et al [33] investigated the antioxidant activity of polyphenolic extracts and fractions from A. bilimbi leaves.…”

“…Averrhoa bilimbi is another plant that has been used in traditional medicine of Asian countries [33]. Ahmed et al [33] investigated the antioxidant activity of polyphenolic extracts and fractions from A. bilimbi leaves. The results showed that A. bilimbi leaf extract had in vitro high free radical scavenging capacity, especially the n-butanol fraction [33].…”

“…Ahmed et al [33] investigated the antioxidant activity of polyphenolic extracts and fractions from A. bilimbi leaves. The results showed that A. bilimbi leaf extract had in vitro high free radical scavenging capacity, especially the n-butanol fraction [33]. Moreover, A. bilimbi leaf extracts inhibited xanthine oxidase, an enzyme involved in oxidative stress and metabolic disorders [33].…”

“…Moreover, A. bilimbi leaf extracts inhibited xanthine oxidase, an enzyme involved in oxidative stress and metabolic disorders [33]. Finally, docking analysis indicated that 5,7,40-trihydroxy-6-(1-ethyl-4-hydroxyphenyl) flavone-8-glucoside (cucumerin A) and afzelechin 3-O-alpha-L-rhamnopyranoside are the possible compounds that are responsible for xanthine oxidase inhibition [33].…”