'Investigation Of The Analgesic Potential Of Methanol Leaf Extract Of Newbouldia Laevis On Wistar Albino Rats:- Ndukwe Chinemerem Ndukwe K

ABSTRACT xiii The analgesic activity of the methanol leaf extract of Newbouldia laevis (MENL) was evaluated in Wistar albino rats using the acetic acid induced writhing reflex, tail immersion, and hot plate experimental models. The extracts were used at the doses of 200, 400, and 800 mg/kg, while 400 mg/kg of acetylsalicylic acid (ASA) was used as the standard reference drug in all the models. In the acetic acid induced writhing reflex all doses of the MENL significantly (p < 0.05) decreased the number of abdominal constrictions (writhing) when compared to the control. Also in the hot plate test all doses of MENL at 200, 400, and 800 mg/kg, when compared to control significantly (p<0.05) increased the pain reaction time (PRT). Meanwhile, in the tail immersion model none of the doses of MENL caused any significant (p<0.05) increase in the pain reaction time when compared to the control. All actions of MENL were dose dependent and comparable to those of ASA group. The acute toxicity test carried out produced neither death nor any sign or form of acute toxicity. Preliminary phytochemical analysis of MENL revealed the presence of carbohydrate, flavonoid, alkaloids, reducing sugar, glycosides, starch, polyuronoid, tannins. These phytochemicals are probably responsible for the analgesic activity effect of MENL. Hence, All these results suggest that Newbouldia laevis has significant analgesic potential and properties which may be acting through both peripheral and central mechanisms, hence, justifies its traditional use in relieving pain.