اثر عصاره آبی- الکلی بخشهای هوایی گیاه اسطوخودوس بر اکتساب و بیان تحمل و وابستگی به مورفین در موش کوچک آزمایشگاهی نر

  Background and Objective: Tolerance and dependence are two major problems of chronic opioids use. Repeated application of Lavandula officinalis has been recommended for a long time in Iranian traditional medicine for some of nervous disorders like epilepsy and dementia. Since anti-convulsant drugs are beneficial in treatment of morphine dependence and with regard to anti-convulsant effects of Lavandula officinalis, the effects of Lavandula officinalis extract (LOE) was studied on acquisition and expression of morphine tolerance and dependence and it was compared with methadone.  Materials and Methods: Morphine was injected either acutely(100 mg/kg) or chronically, with gradually increasing doses twice daily for 7 days, Exept in 8th day in which morphine was administrated in a single dose (100 mg/kg). In either acutely or chronically with: saline, LOE 200 mg/kg, LOE 400 mg/kg, methadone 5 mg/kg, methadone + LOE 200, methadone + LOE 400 was administrated 60 min prior to morphine injection. Morphine tolerance was measured by tail immersion test, before and after administration of morphine in test day. Morphine dependence was also evaluated by counting the number of jumps after injection of naloxone (5mg/kg) in test day. All drugs were given in a volume of 0.3 ml intraperitoneally.   Results: LOE and methadone, significantly decreased acquisition (but not expression) of morphine tolerance and dependence (P<0.05). Chronic administration of LOE and (not methadone) reduced physical dependence induced by single dose of morphine (P<0.05).   Conclusion: Chronic administration of Lavandula officinalis better than methadone inhibits morphine tolerance and dependence in mice.