EVALUATION OF ANALGESIC AND ANTI-INFLAMMATORY EFFECT OF TERMINALIA ARJUNA ETHANOL EXTRACT

The present study was conducted to assess the anti-inflammatory, analgesic and cytotoxic properties of 50% ethanol extract of the stem bark of Terminalia arjuna plant on laboratory animal. In vitro cytotoxicity test was studied by Brine Shrimp Lethality Bioassay and results illustrated significant (p<0.05) cytotoxicity against A. salina, that were expressed as LC­­­­₅₀. Terminalia arjuna ethanol extract showed brine shrimp cytotoxicity with lethal concentration 50 (LC₅₀) value of 50.11μg/ml. Carrageenan-induced paw edema method was done to study the anti-inflammatory effect and it was found that T. arjuna can be effective in acute inflammatory disorders and in that case it showed significant result (p<0.001) with both of the 250mg/kg and 500mg/kg dose level. The extract was also used to evaluate the centrally acting analgesic potential using formalin, hot plate and peripheral pharmacological actions using acetic acid induced writhing test in mice. The extract of the plant were found to have significant (p<0.01; p<0.001) analgesic activity at the oral dose of 250 & 500mg/kg body weight, in the tested models. In hot plate test, at both dose levels (250mg/kg and 500mg/kg), T. arjuna extract showed significant (p<0.001) increased latency period than the control group. In acetic acid induced writhing test and formalin test  T. arjuna also showed reduced number of writhes than the control group at two dose levels which are significant (p<0.05; p<0.001) compared to control. The results obtained support the use of stem bark of T. arjuna in painful conditions acting both centrally and peripherally.