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

Abstract

OBJECTIVE: To evaluate the anti-nociceptive activity of Tecomaria capensis (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.) significantly 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.