Objectives: To screen the analgesic effect of aqueous and alcoholic extract of Madhuka longifolia and elucidate its probable mechanism of action. Method: The analgesic effect was screened through tail flick, hot plate and chemical writhing methods. The probable mechanism of action through opioid receptors was elucidated by i.m. administration of naloxone - specific antagonists 30 min before the last dose of aqueous or alcoholic extract of M.longifolia . Result: Graded doses of both aqueous and alcoholic extract of M.longifolia (4.0 to 64.0 mg/kg, i.m . X 3 days) produced dose dependent analgesic effect in all the three nociceptive methods carried out either in rats or mice. The analgesic effect exhibited by both the extracts was not antagonized by naloxone in rats only. Conclusion: The analgesic effect exhibited by both aqueous and alcoholic extracts does not mediate through opioid receptors.
DINESH CHANDRA (Thu,) studied this question.