The In Vivo Analgesic Activity of Aqueous and Ethanolic Extracts of Anacardium occidentale occidentale Linn and Cymbopogon citrates DC

Abstract

Background: The problems associated with the use of non-steroid anti-inflammatory drugs (NSAIDs) as analgesics underline the urgent need to screen and identify plant material used as pain relievers in traditional medicine. The purpose of this work is to determine the analgesic activities of Anacardium occidentale and Cymbopogon citratus, plants used in ethnomedicine. Crude aqueous and ethanolic extracts of A. occidentale and C. citratus at the doses of 50 and 100mg/kg body weight were evaluated for analgesic activities in male and female albino mice.
Methodology: Analgesic activities of the experimental plants were  evaluated using the acetic acid induced writhing (pains) response. In this method, acetic acid is injected intraperitoneally to the experimental animals and the response is contraction of the abdominal muscles and the stretching of the hind limps. Results: All the extracts at doses 50 and 100mg/kg body weight produced various analgesic responses in a dose dependent manner. There was a significant (P < 0.05) reduction in writhing at 100mg/kg body weight in both aqueous and ethanolic extracts of A. occidentale and C. citratus. The standard drug, Piroxicam also produced a significant (P < 0.05) reduction in writhings, producing pain inhibition of 70.3 %. Conclusions: The analgesic effects produced by crude extracts of both experimental plants confirm that they are endowed with analgesic properties. Further work is suggested to isolate active chemical principles of these plants, and to elucidate the full mechanisms of analgesic action.

Key Words: Anacardium occidentale, Cymbopogon citratus, Analgesic Activity