Effect of Rosmarinus officinalis L. aerial parts extract on morphine withdrawal syndrome in mice.

The effect the aqueous and ethanol extracts of Rosmarinus officinalis L. aerial parts on morphine withdrawal syndrome was investigated in mice. The aqueous and ethanol extracts induced a significant antinociceptive activity in the writhing test. This activity was inhibited by naloxone pretreatment. Dependence was induced using subcutaneous injections of morphine daily for 3 days. On day 4, morphine was injected 2 h prior to the intraperitoneal injection of naloxone. The number of jumps during the 30 min period after naloxone injection was considered as a measure of the withdrawal syndrome. The results indicated that the aqueous (1.68 g/kg and 2.4 g/kg, i.p.) and ethanol (0.96 g/kg, i.p.) extracts reduced the number of jumps. Phytochemical study indicated that only the aqueous extract of R. officinalis has an alkaloid component. It is concluded that the aqueous and ethanol extracts of R. officinalis aerial parts could diminish morphine withdrawal syndrome. Copyright 2003 John Wiley & Sons, Ltd.