An anti-ulcerogenic flavonol diglucoside from Equisetum palustre L

The aerial parts of Eqiusetum palustre L. is used to treat peptic ulcer in Karaman, Turkey.

The present study was undertaken to evaluate the in vivo gastroprotective potential and structure elucidation of the active constituent(s) through bioassay-guided fractionation procedures by using ethanol (EtOH)-induced ulcerogenesis model in rats.

The 80% ethanol extract of the aerial parts was subjected to subsequent separation procedures such as solvent-solvent partition and column chromatography through bioassay-guided fractionation techniques to isolate the active anti-ulcer component(s) by using the EtOH-induced ulcer model in rats. The ulcer index was used to evaluate and to calculate the gastroprotection percentage.

The subextracts, n-butanol and remaining H2O, of Equisetum palustre showed potent in vivo gastroprotective activity. Bioassay-guided fractionation has revealed that a flavonol diglucoside, was isolated as an active constituent from the n-BuOH subextract of Equisetum palustre. Structure elucidation by standard spectroscopic techniques (1H NMR, 13C NMR and DEPT, etc.) revealed that this compound as kaempferol-3-O-1''-beta-d-glucopyranosyl-3-O-1'''-beta-D-glucopyranoside, which provided remarkable protection at 250 and 500 mg/kg doses (69.5 and 98.5% ulcer inhibition, respectively) against ethanol-induced gastric lesions.

Experimental data confirmed the ethnobotanical usage of Equisetum palustre, with scientific evidence, in Turkey. Additionally, kaempferol-3-O-1''-beta-D-glucopyranosyl-3-O-1'''-beta-D-glucopyranoside, a known compound, was defined as an anti-ulcerogenic compound in the present work for the first time.