Analgesic, anti-inflammatory and antipyretic studies on the residual aqueous fraction of <i>Uapaca togoensis</i> (Pax) stem bark in rodents

Abstract

Uapaca togoensis Pax. (Euphorbiaceae) is used in traditional medicine to treat several diseases including pain, inflammation and fever. This study investigated analgesic, anti-inflammatory and anti-pyretic effects of the residual aqueous fraction of the plant. Preliminary phytochemical screening and acute toxicity studies were conducted. Analgesic activity was evaluated using acetic acid-induced writhing, hot plate and formalin-induced pain tests at doses of 250, 500 and 1000 mg/kg, p.o. Anti-inflammatory and antipyretic activities were investigated using carrageenaninduced paw edema and Brewer’s yeast-induced pyrexia model respectively in rats. Oral median lethal dose of the fraction was found to be greater than 5000 mg/kg. The fraction significantly (p<0.05) reduced the number of acetic acid-induced writhes and increased the reaction time of mice to thermal stimuli. In the formalin test, a significant (p<0.05) reduction in mean pain score was observed at the second phase. A significant (p<0.05) decrease in paw edema at the 4th and 5th hours and a reduction in temperature was also observed at the 22nd hour. Phytochemical screening revealed the presence of saponins, tannins, steroids, cardiac glycosides, flavonoids, alkaloids and triterpenes. The result of the study revealed that the fraction possesses analgesic, anti-inflammatory and antipyretic activities, validating the folkloric use of the plant.

Keywords: Analgesic, Anti-inflammatory, Anti-pyretic, Uapaca togoensis, Residual Aqueous Fraction