Analgesic effect of ethanolic leaf extract of moringa oleifera on albino mice

Abstract

Objectives: Moringa oleifera is a highly valued plant distributed in many countries of the tropic and subtropics. Moringa oleifera leaves are a potential source of phytochemical ingredients claimed to have analgesic property. Pain is an unpleasant sensation, which in many cases represents the only symptom for the diagnosis of several diseases. Therefore analgesic drugs lacking the side effect as alternative to nonsteroidal anti-inflammatory drugs (NSAIDs) and opiates are in demand by the society. The present study is undertaken to evaluate the analgesic activity of Moringa oleifera using acetic acid induced writhing test and Eddy's hot plate test. Materials and Methods: It is a randomized control study. The present study was done using two experimental models. The albino mice were divided into six groups, each group consisting of 6 mice. A total of 36 mice were used in each of the two experimental models. Group I: Control (normal saline given orally at 2 ml/kg body weight); Group II: Standard (diclofenac 10 mg/kg i.p/ morphine 1 mg/kg i.p); Group III, IV, V, VI (ethanolic extract of Moringa oleifera (EMO) 50, 100, 200, 400 mg/kg, respectively). The EMO leaves were administered at 50, 100, 200, 400 mg/kg doses orally 1 hour before the experiments. For peripheral analgesic effect, acetic acid induced writhing test was used. The central analgesic effect was screened using Eddy's hot plate method. The standard drug used in acetic acid induced writhing test was diclofenac and in Eddy's hot plate test was morphine. Results: The EMO leaf showed significant (P < 0.01) analgesic activity at 100, 200, 400 mg/kg in the acetic acid induced writhing test showing 32.21%, 59.71% and 78.61% inhibition of writhes, respectively in comparison with the control. In the Eddy's hot plate test EMO at 400 mg/kg showed significant (P < 0.01) analgesic activity from 15 min to 90 min with a mean rank ranging from 28.92 to 26.00, second mean rank following morphine in comparison with control. In both the tests, EMO showed significant (P < 0.01) analgesic activity in a dose-dependent manner. Conclusion: The ethanolic leaf extract of Moringa oleifera exhibited analgesic activity in both models showing its both central and peripheral analgesic actions.