Involvement of opioid and monoaminergic pain pathways in Aegle marmelos induced analgesia in mice.

OBJECTIVE

To study analgesic activity and to evaluate the involvement of opioid and monoamines in the antinociceptive activity of methanol extract of leaves of Aegle marmelos.

METHODS

Analgesic activity of methanol extract (ME) of A. marmelos alone (75,150 and 300 mg/kg orally) and in combination with morphine or venlafaxine (subanalgesic) were studied using tail flick test and acetic acid-induced writhing in mice. The effect of pre-treatment with opioid antagonist naltrexone 1mg/kg was also studied on antinociception induced due to ME.

RESULTS

ME produced a dose-dependent significant antinociceptive activity in the tail flick test and acetic acid-induced writhing in mice. (P<0.05) Administration of subanalgesic dose of ME with morphine or venlafaxine also resulted in significant (P<0.05) antinociceptive activity in both the pain models. Pre-treatment with naltrexone inhibited analgesic activity induced by ME alone and combination with morphine or venlafaxine.

CONCLUSIONS

A.marmelos in induced antinociception is mediated through both opioid and monoaminergic pain pathways, suggest its possible use in chronic pain.