Effect of Salvia leriifolia leaf extract on morphine dependence in mice

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