Evaluation of anti-inflammatory and analgesic effects of aqueous extract obtained from root powder of Inula racemosa Hook. f.

Abstract

Root extract of Inula racemosa is widely used in Ayurvedic and folk medicine. Particularly in China and India, it is used for treating human diseases including cardiovascular, inflammation and abdominal pain. However, the root extracts are not scientifically investigated. This study was undertaken to evaluate the anti-inflammatory and analgesic activities of aqueous extract obtained from root powder of I. racemosa along with screening of secondary metabolites. The anti-inflammatory activity was evaluated in carrageenan induced rat paw edema model. The analgesic effect was measured in mice using acetic acid-induced writhing test and tail-immersion test. The treatment regime consisted of distilled water for Group I as control and three doses of aqueous extract (100, 200 and 400 mg/kg) and standard drugs, indomethacin (10 mg/kg) or aspirin (100 mg/kg) for the Groups, 2, 3, 4 and 5, respectively, fed orally. Respective groups were injected carrageenan or acetic acid and their endpoints was measured based on time periods. Saponins, terpenes, phenolics, flavonoids and glycosides were detected in aqueous extract. Anti-inflammatory and analgesic activities of aqueous extract were found to be highest at 60 and 63%, respectively, at the dose of 400 mg/kg and comparable to the respective standard drugs. The aqueous extract effect in tail immersion test was also found to be dose dependent. The effective anti-inflammatory and analgesic activities of aqueous extract of I. racemosa positively correlate with respect to their dose.