RESUMEN
OBJECTIVES: The purpose of this study was to assess the gastroprotective properties of the methanol extract and the diterpene marrubiin obtained from the leaves of M. vulgare. METHODS: Assays were performed using different protocols in mice. Studies focusing on mechanisms of gastroprotection were also undertaken. KEY FINDINGS: In the model of ethanol-induced ulcers, we observed a significant reduction in all the parameters analysed; the curative ratios obtained were 49.31±0.57, 74.31±0.91 and 79.86±0.59 for the groups treated with 50 and 100mg/kg of extract of M. vulgare and omeprazole (30mg/kg), respectively. For indomethacin-induced ulcers, the percentages of ulcer inhibition were 50.32±5.60, 66.24±4.30, 82.17±04.09 and 67.52±4.38, for the groups treated with 25, 50 and 100mg/kg M. vulgare and positive control (cimetidine), respectively. In both models, the marrubiin (25mg/kg) produced a significant reduction in all the parameters when compared with the control group (P<0.01). There was also a significant increase in pH and mucus production in the groups treated with M. vulgare extract and marubiin. The results also demonstrated that the gastroprotection induced by the extract and marubiin is related to the activity of nitric oxide and endogenous sulfhydryls, which are important gastroprotective factors. CONCLUSIONS: The results of this study show that the extract of M. vulgare and marrubiin displays antiulcer activity and that this effect can be partly attributed to the isolated diterpene.