In vivo evaluation of analgesic activity of methanolic extract of Laportea interrupea (L.) leaves

The study was carried out to evaluate analgesic activity of methanolic extract of Laportea interrupea (L.). For evaluation of analgesic activity acetic acid induced writing test and tail immersion test were performed in Swiss albino mice. The leaves extract were administered orally at different doses and the obtained effects were compared with commercially available analgesic and anti-inflammatory drug paracetamol and acetyl salicylic acid (ASA) respectively. In analgesic bioassay the leaves extract significantly reduced the writhing induced by acetic acid as well as increase pain reaction time (PRT) in tail immersion test. The degree of inhibition of writing of the leaves extract were10.98%, 23.30% and 50.75 % when doses were 25mg/kg, 50mg/kg and 100mk/kg respectively, compared to the effect of standard analgesic drug, paracetamol was 61.17% at a dose 65mg/kg. In tail immersion test, PRT was increased from 2.57±0.05 to 4.52±0.08 with increasing doses from 200mg/kg to 800mg/kg and time from 60 minutes to 120 minutes compared to standard drug, ASA were 4.29±0.18 and 5.68±0.43 at time 60,120 minutes respectively at a dose 200mg/kg. In both of the test 0.9 % NaCl was used as control. In conclusion, the experimental data demonstrated that methanolic extract of L. interrupea leaves possess remarkable analgesic activity.