Vol. 4, Issue 2 (2015)

Author(s):
Nishanthini D., Jesudoss Prabhakaran A.C., Isabella Topno, Balakrishnan S.

Abstract:
Aim: To evaluate the anti-nociceptive activity of Emblica officinalis using acetic acid induced writhing test and eddy’s hot plate method in mice and to investigate the role of opioid receptors in the central anti-nociceptive activity of Emblica officinalis.
Materials and Methods: Peripheral analgesic activity of Emblica officinalis was evaluated using acetic acid induced writhing test. Indomethacin (10 mg/kg, p.o) was used as the standard drug and Emblica officinalis was used at a dose of 300 mg/kg, p.o. Central anti-nociceptive activity of Emblica officinalis was evaluated using eddy’s hot plate method. Morphine (5 mg/kg,i.p) was used as the standard drug and Emblica officinalis was used at a dose of 300 mg/kg, p.o. To assess the role of opioid system, the other groups of animals were pretreated with μ opioid receptor antagonist (CTAP-1 mg/kg, i.p), δ opioid receptor antagonist (Naltrindole-1 mg/kg, i.p) and κ opioid receptor antagonist(Nor-Binaltorphimine-1 mg/kg,i.p) and then treated with vehicle/Emblica officinalis. Results were analysed using one way ANOVA followed by Tukey’s multiple comparison test. p value of <0.05 was considered significant.
Results: Emblica officinalis decreased the number of writhings significantly (p<0.001) in acetic acid test when compared to control group. Administration of Emblica officinalisincreased the latency time significantly (p<0.05) when compared to control group in hot plate model. Further, administration of CTAP prior to Emblica officinalis reversed the anti-nociceptive effect significantly (p<0.001) when compared to Emblica officinalis group.
Conclusion: Emblica officinalis possesses analgesic effect in both central and peripheral models of nociception. The central anti-nociceptive activity probably mediated via μ opioid receptor.