Anti-inflammatory, analgesic and antipyretic properties of ethanolic extracts of three plants of Benin pharmacopoeia: Euphorbia hirta, Citrus aurantifolia and Heterotis rotundifolia

Abstract Objective Euphorbia hirta , Citrus aurantifolia and Heterotis rotundifolia are commonly used in Benin in the treatment of infectious diseases. The aim of this study is to evaluate the anti-inflammatory, analgesic and antipyretic properties of ethanolic extracts of these plants. The study was performed on wistar rats with 200 mg/kg b.w.Results Administration of these extracts prevents edema inflammatory induced by 2% formalin in rat paw. Inhibition percentages of edema vary between 23.67% and 86.76% for the three extracts. These extracts have similar anti-inflammatory activity (p> 0.05) to that of diclofenac at 50 mg/kg. Analgesic activity show that these extracts inhibit very significantly (p<0.001) the pain induced by 3% acetic acid and the highest inhibition percentage is 60.34% (Citrus aurantifolia ). This percentage is like to that of acetylsalicylic acid (67.35%) administered at the same dose. Likewise, these extracts attenuate significantly (p <0.05) the thermal pain induced by tail immersion of each rat in hot water at 50°C. Indeed, these extracts, reduces very significantly (p <0.001) pyrexia induced by 20% beer yeast suspension in rats and they have similar effect (p> 0.05) to that of acetylsalicylic acid at the fourth hour. These results prove, some traditional therapeutic indications of these plants.