Peptic ulcer disease, the most common gastrointestinal disorder, is currently treated with several types of drugs, but all have severe side effects. The aim of the present study was to evaluate the gastroprotective activity of juanislamin, isolated from Calea urticifolia, in a rat model of ethanol-induced gastric lesions. Thirty minutes after orally administering a given dose of juanislamin (from 1 to 30 mg/kg) or carbenoxolone (the reference drug, at 1-100 mg/kg) to rats, 1 mL of ethanol was applied, and the animals were sacrificed 2 h later. The stomachs were removed and opened to measure the total area of lesions in each. To examine the possible participation of prostaglandins, nitric oxide and/or sulfhydryl groups in the mechanism of action of juanislamin, the rats received indomethacin, NG-Nitro-l-arginine methyl ester hydrochloride (l-NAME) or N-ethylmaleimide pretreatment, respectively, before being given juanislamin and undergoing the rest of the methodology. Juanislamin inhibited gastric lesions produced by ethanol in a non-dose-dependent manner, showing the maximum gastroprotective effect (100%) at 10 mg/kg. The activity of juanislamin was not modified by pretreatment with indomethacin, l-NAME or N-ethylmaleimide. In conclusion, juanislamin protected the gastric mucosa from ethanol-induced damage, and its mechanism of action apparently does not involve prostaglandins, nitric oxide or sulfhydryl groups.
Keywords: Calea urticifolia; juanislamin; sesquiterpene lactone.