RESUMEN
Nowadays the medicinal herbs are considerably used to decrease the symptoms of drug withdrawal syndrome and facilitate this process. According to anti-pain and anti-anxiety effects of Hypericum scabrum, this research was done to study acute effects of hydroalcoholic extract of Hypericum scabrum on morphine withdrawal symptoms in adult male NMRI mice strain. In this experimental study, adult male mice were divided into two main groups of control and experimental. The control group received morphine and naloxone. The experimental group received morphine and 10, 20 and 30 mg/kg doses of Hypericum scabrum. During three days and three times of each day with five hours intervals, the animal received 10, 20 and 30 mg/kg doses respectively and in the fourth day they received 40 mg/kg drug subcutaneously [Marshall method]. In chronic method, 10, 20 and 30 mg/kg doses of Hypericum were injected to three groups of morphine intraperitoneally. To induce withdrawal syndrome in all groups, three hours after the last morphine injection, one dose of 5mg/kg of naloxone was injected intraperitoneally. In all groups, after naloxone injection the symptoms of morphine withdrawal including jumping, standing on two feet, climbing up the wall and weight loss was considered. Acute injection of the Hypericum scabrum could significantly decrease the symptoms of morphine withdrawal in comparison with morphine group. Decreasing symptoms of morphine withdrawal probably ordinates from Hypericum scabrum opioid-like effects