ABSTRACT
Melissa officinalis [MO] grows in the different parts of Iran abundantly. In previous studies, the extract of MO has been reported to have antinociceptive and anticonvulsive effects in rats. This study was designed to evaluate the effect of different doses of the aqueous decoction extracts of MO on withdrawal syndrome in rats. 40 male albino rats [25-30 gr] were selected for this study. Morphine was used to produce drug dependency by Marshall method [injection of 10 doses of drug in four days]. 30 min before injection of naloxone [2 mg/kg], different doses of the extract [5, 10, 25 mg/kg] were injected intraperitoneally and saline [l0ml/kg IP] was injected into the rats of control group. Assessment of classic withdrawal syndrome was based on the number of jumps and the weight of the fecal material for every rat. The results of this study indicated that injection of doses of 10, 25 mg/kg of the extract led to a significant decrease in the number of Jumps [p=0.005] and also in the weight of feces of the rats [p=0.01]. We conclude the aqueous extract of MO can have an important role in the reduction of the severity of withdrawal syndrome in rats