Evaluation of anti-nociceptive activity of methanolic extract of Tecomaria capensis Thunb.(Bignoniaceae) leaves in rats

Objective:To evaluate the ann-nociceptive activity of Tecomaria capensls(T.capensis) leaves extract(TCLE) using different models in rats by acetic acid induced writhing test,(b) tail-flick test(c) tail-clip test.Methods:TCLE(100,300,1000 and 2000 mg/kg body wt.) was given to rats orally to observe acute toxicity for 14 d.Then test drug TCLE were given at dose of 100,200 and 500 mg/kg p.o.and standard drug aspirin were given at a dose of 100 mg/kg p.o.Results:No mortality was reported even after 14 d.This indicates that the methanol extract is safe up to a single dose of 2 000 mg/kg body weight TCLE(100,200 and 500 mg/kg p.o.) significandy inhibited abdominal constrictions(writhing) induced by acetic acid and increased the latency period in the tail flick and tail clip test.TCLE at the dose of 500 mg/kg showed significant anti-nociceptive activity compared to standard aspirin.Discussions:The results of this study show that methanol extract of T.capensis possesses anti-nociceptive activity which may be mediated by the central and peripheral mechanisms.