Analgesic and anti-flammatory activities of the aqueous leaf extract of <i> Solanum nigrum</i> Linn (solanaceae) in rats

Abstract

The analgesic and anti-inflammatory activities of aqueous leaf extract of S. nigrum was investigated in rats. Thermally-induced pain and pressure-induced pain were used to assess the analgesic activity of the extract while egg albumin-induced oedema was used for anti-inflammatory activity. The aqueous leaf extract of S. nigrum at doses of 30 mg/kg and 60 mg/kg, ip exhibited a significant (P<0.05) dose- dependent analgesic activity on thermally-induced pain
in rats. In the pressure-induced pain model, the extract increased pain threshold at dose levels of 40 mg/kg (P<0.05) and 60 mg/kg (P<0.01). The extract at 60 mg/kg produced analgesic activity similar to aspirin 10 mg/kg; however, the analgesic effect of the extract was not as prolonged as that obtained by the standard. The aqueous extract of S. nigrum at doses of 40 mg/kg and 60 mg/kg showed 23.5% (P<0.05) and 32.1% (P<0.01) inhibition of paw oedema respectively
at the end of two hours. The present study indicates that the aqueous leaf extract of S. nigrum has anti-inflammatory and analgesic activities that could be mediated via modulators of pain and inflammation or through central activity. © 2006: NAPA. All rights reserved