Gastroprotective effect of abscisic acid O-β-D- glucopyranoside isolated from Malpighia glabra L. cultivated in Egypt

Abstract

The secondary metabolites profile of Malpighia glabra L. leaves methanol extract using UPLC-Quadra-TOF-MS/MS analysis detected fifty-one compounds, including eleven phenolic acids, eighteen flavonoids of different classes flavonoid glycosides, flavanone, flavone, flavanol. Moreover, one stilbene glycoside, two triterpenes; one iridoid, three growth regulators in addition to primary metabolites. All metabolites were tentatively identified by comparing retention periods and fragmentation patterns of their mass spectra and MS/MS spectra to previously reported data. Six compounds; tithoniaquinone A glucoside, epicatechin, epiafzelechin, epicatechin 8-C-β-D-galactoside, physalin B, abscisic acid O-β-Dglucopyranoside (ABAGE) underwent isolation and innovatively identified from butanol extract of M. glabra leaves. Measurement of the antioxidant activity of ABAGE pure compound was done using Diphenyl-1picrylhydrazyl (DPPH) assay and Trolox as standard. Gastroprotective activity of ABAGE (single oral dosages between 200 and 400 mg/kg body weight) one hour before ulcer induction by ethanol in Albino rats was examined using Omeprazole as the standard drug. ABAGE exhibited no liver or renal toxicity. ABAGE greatly improved the action of superoxide dismutase (SOD) and glutathione (GSH); the antioxidant enzymes, and enhanced GSH together with decreasing MDA which are suggested to be through avoiding oxidative damage caused by free radicals. ABAGE had the effect of decreasing nitric oxide (NO) activity which is suggested to be by inhibiting signal-induced tumor necrosis factor (TNF) transcription in addition to control of cytokine induction during inflammation. ABAGE exhibited a great gastroprotective impact on acute gastric ulcers caused by ethanol in rats.