Effect of Salvia leriifolia leaf extract on morphine dependence in mice.

The effect of Salvia leriifolia leaf extract on morphine dependence was investigated in mice. Dependence was induced using subcutaneous injections of morphine daily for 3 days. On day 4, morphine was injected 2 h before the intraperitoneal injection of naloxone. The number of episodes of jumping during the 30 min after injection of naloxone was considered as the intensity of the withdrawal syndrome. The ethanol extract reduced the number of jumping episodes dose-dependently. The extract at a dose of 500 mg/kg was as effective as a dose of 5 mg/kg of diazepam in reducing the number of jumping episodes. The effect of the extract was blocked by aminophylline (20 mg/kg), a non-selective antagonist of adenosine receptors. It is concluded that the ethanol extract of S. leriifolia leaves could diminish the withdrawal syndrome of morphine. Copyright 2000 John Wiley & Sons, Ltd.