Analgesic Activity of the Methanolic Leaf Extract of <i>Jatropha Curcas</i> (Linn)

Abstract

This study evaluated the analgesic activity of the metabolic leaf extract of Jatropha curcas (Linn) in vivo using analgesic models viz: Hot plate method in mice, tail flick or immersion method in rat and acetic acid-induced writhing reflex model in mice. In all the models, acetylsalicylic acid (ASA) was used as the reference drug. In the hot plate and tail flick models, the oral administration of J. curcas extract at the doses of 100, 200 and 400 mg/kg and the reference drug ASA (400 mg/kg) showed potent analgesic effect by significantly (P<0.001) increasing the pain reaction time dose dependently in mice and rats. Also the reference drug and the extract of J. curcas significantly (P<0.0001) decreased the number of the abodominal contortions in the acetic acid-induced writing reflex in mice and increased the percentage protection in a dose dependent manner. In conclusion, this study indicates that the methanolic leaf extract of Jatropha curcas has significant analgesic properties and may be acting through both peripheral and central pain mechanisms.

Key words:Analgesic, Jathropha curcas, hot plate, tail flick, writhing reflex, acetylsalicylic acid.