Ethnopharmacological relevance: The aerial parts of Eqiusetum palustre L. is used to treat peptic ulcer in Karaman, Turkey.
Aim of the study: 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.
Material and methods: 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.
Results: 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.
Conclusion: 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.