In vivo Anti-inflammatory and Analgesic Activities of Ethanol Leaf Extract of Stevia rebaudiana in Albino Rats

Abstract

The present study was undertaken to investigate the anti-inflammatory and analgesic activities of ethanolic extract of Stevia rebaudiana leaf in experimental rats. Swiss albino rats were administered with oral dose of ethanolic leaf extract of S. rebaudiana at the doses of 200, 300, 400 and 500 mg/kg body weight, and studied for its anti-inflammatory and analgesic activities by using carrageenan-induced hind paw edema, acetic acid-induced writhing, hot plate reaction and tail immersion test in albino rats. Inhibition in paw volume was measured plethysmometrically at different time intervals after carrageenan (1% w/v) injection. As a result, the ethanolic leaf extract of S. rebaudiana showed anti-inflammatory and analgesic effects in dose dependent manner when compared with the control and standard drug, aspirin (100 mg/kg, p.o). The paw volumes, pyrexia and writhes in experimental rats were reduced significantly (p < 0.05) as compared to that of control, and hot plate test showed significant licking effect in rats. Phenylbutazone, aspirin, morphine and diclofenac sodium were employed as reference drugs for analgesic and anti-inflammatory studies. In the present study, high dosages of the ethanolic leaf extract of S. rebaudiana (300, 400 and 500 mg/kg body weight) demonstrated significant anti-inflammatory and analgesic activities in the tested models. Findings of this investigation suggested a potential benefit of ethanolic leaf extract of S. rebaudiana in treating conditions associated with pain and inflammation.