The phytochemical and anti-nociceptive evaluation of the methanol extract of Newbouldia laevis (Bignoniaceae) leaves using animal models

This present study was carried out to evaluate the anti-nociceptive activity of Newbouldia laevis leaves extract (NLLE) using acetic acid induced writhings in mice, hot plate and tail-flick test. The leaf, stem, stem bark and fruits have been used for febrifuge, stomach ache and tooth ache (Iwu, 2000; Lewis and Manony, 1997). The phytochemical screening and acute toxicity was studied. A significant (P < 0.050 increase in the latency period in the tail flick and hot plate test was observed for the treatment with NLLE at dose of 100, 200 and 400 mg/kg b.wt. i.p after 30 and 45 min. In hot plate method, the percentage observed after 45 min was 48.31, 67.05, 86.16 and 89.17 for NNLE at the 100, 200 and 4000 mg/kg b.wt. and piroxicam (20 mg/kg) respectively while in tail flick method, 28.04, 41.66 and 60.85% reaction time was observed with 100, 200 and 400 mg/kg b.wt. of NLLE. A 31.92, 53.58 AND 67.47% (P < 0.05) inhibition of writhing was observed with NLLE at 100, 200 and 400 mg/kg b.wt.i.p which was found comparable to piroxicam (20 mg/kg) which inhibited 72.38% (P < 0.05) of writhing reflex. Acute toxicity studies showed it has a wide margin of safety and good tolerance at 5000 mg dose. The phytochemical analysis of the extract revealed the presence of carbohydrates, alkaloids, resins, steroids and flavonoids. The result showed that the methanol extract of Newbouldia laevis possesses anti-nociceptive activity which may be mediated by the central and peripheral mechanisms and supports the traditional uses of the plant in the treatment of pains and inflammation.

References:

[1] Iwu, MM (2000). Handbook of African Medicinal Plants. London: CRC, Press, Inc; p. 19.

[2] Lewis, WH, Manony, PFE (1997). Medical Botany: Plants Affecting Man's Health. New York, USA. Johny Wiley and Sons, p. 240.