European journal of pharmacology
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Sinomenine, a major bioactive ingredient isolated from traditional Chinese medicine Sinomenium acutum, has been reported to have analgesic effects in various pain animal models. N-demethylsinomenine, the N-demethylated product of sinomenine, has been identified to be the major metabolite of sinomenine and is also a natural component extracted from Sinomenium acutum. This study examined the anti-allodynic effects of N-demethylsinomenine in a mouse model of postoperative pain. ⋯ The anti-allodynia induced by N-demethylsinomenine (40 mg/kg, s.c.) was attenuated by bicuculline, a selective γ-aminobutyric acid type A (GABAA) receptor antagonist. In addition, the doses of N-demethylsinomenine used here did not alter the locomotor activity in mice. Our findings demonstrated that N-demethylsinomenine exerts behaviorally-specific anti-allodynia against postoperative allodynia mediated through the GABAA receptors, suggesting it may be a useful novel pharmacotherapy for the control of postoperative pain.