RESUMEN
This study was initiated to investigate the effect of Portulaca oleraceae on morphine dependence in mice. Dependence was induced using the subcutaneous injections of morphine for 3 days. On the day 4, morphine injected 2 h prior to intraperitoneal injection of naloxone. The plant extracts ethanolic or aqueous administered 0.5 h before the final dose of morphine. The number of jumping during the 30 min period after naloxone injection was considered as a measure of withdrawal syndrome. Both extracts reduced the jumping episodes dose-dependently. The maximum effect was observed at doses of 0.28 g/kg and 1.4 g/kg for the aqueous and ethanolic extracts, respectively. Clonidine and extracts decreased the total activity in locomotion test. These findings indicated that Portulacea oleraceae extracts can decrease morphine dependence in mice