BIOASSAY-GUIDED FRACTIONATION OF ANTINOCICEPTIVE EFFECT OF LECANIODISCUS CUPANIOIDES USING MICE
Abe A. I., Wakeel O. K.* and Olapade M. K.,
Objective: Lecaniodiscus cupanioides belong to the family Sapindaceae, used traditionally for the treatment of tooth ache, fever and swelling of the abdomen, boils and wounds most especially in the western part of Nigeria. In this present study, we evaluated the effects of the methanol extract and fractions obtained from Lecaniodiscus cupanioides using acetic acid-induced writhing, hot plate test and formalin-induced paw lick and the possible mechanism of action of the most potent fraction. Materials and Methods: Methanol extract and the partitioned chromatography fractions (n-HF, DCMF, EAF, and AF) of the plant obtained according to the standard methods were screened for anti-nociceptive activity. Male Swiss albino mice (20-22 g) were used (n=5 in each group). The experimental models used to assess the anti-nociceptive activity were Acetic acid-induced writhing, formalin, and hot-plate tests. Morphine (5 mg/kg, i.p.) and acetylsalicylate (ASA, 150 mg/kg, i.p.) were used as standard drugs in hot plate, formalin and acetic acid-induced writhing test respectively. Results: The methanol extract (ME) and fractions (EAF, and AF) significantly reduced abdominal constrictions in acetic acid, hot plate, and licking behavior of both acute and chronic phases of formalin test. While, fraction DCMF abolished the pain due to acetic acid and second phase of formalin. ME and AF significantly elevated the reaction time to pain in a dose related-manner in hot-plate test compare with control vehicle while fraction n-HF was not significant. The anti-nociceptive effect exhibited by AF in the formalin-induced paw licks was reversed by the systemic administration of naloxone in inflammatory phase, while both phases were blocked by atropine. Conclusion: Lecaniodiscus cupanioides methanol extract and fractions (EAF, AF and DCMF), showed anti-nociceptive effect. The effect produced is both peripherally and centrally mediated and the study revealed that the phyto-constituents that are polar in nature may responsible for the central effect of the plant. Aqueous fraction probably exhibited its action via opioid or muscarinic cholinergic pathways.
Keywords: Lecaniodiscus cupanioides; Writhing test; Formalin test; Hot plate test; Anti-nociceptive.
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