Analgesic and anti-inflammatory activities of Nicotiana rustica total extract

The antinociceptive and anti-inflammatory activities of Nicotiana rustica Linn. (Solanaceae) total extract (NRTE) have been studied using chemical and thermal models in mice. NRTE was obtained by methanol extraction of dried leaves of N. rustica and was administered intraperitoneally at doses of 2.5, 5, 8.5, and 12 mg/kg body wt (bw). It showed significant protective effects against chemical stimuli in the acetic acid and formalin tests. The extract also showed an inhibitory effect in xylene-induced ear edema compared with the reference drug, diclofenac, and produced a significant increase of the latency time of the reaction in the hot-plate test. Furthermore, the antinociceptive effect of NRTE (at a dose of 12 mg/kg bw) was suppressed by naloxone (a non-specific antagonist of opioid receptors) in hot-plate and formalin tests. This is the first report on the analgesic properties of this plant. The extract might act through an opioid-mediated mechanism. These findings suggest that central and peripheral mechanisms are both involved in the analgesic and the anti-inflammatory effects of N. rustica.