Piper pedicellatum C. DC. Leaf Methanol Extract Inhibits Edema and Granuloma and Modulates Mediators and Cytokines in Rats

Background: Piper pedicellatum is an ethnomedicinal plant used in various inflammatory conditions by many ethnic groups and exploration of its therapeutic potentials is imperative. Objective: This study was carried out to assess anti-inflammatory potential of the methanol extract of the plant leaves using in vivo experiments to validate the traditional uses. Materials and Methods: Carrageenan-induced paw edema and Cotton pellet-induced granuloma models were used to investigate into the anti-inflammatory potential of the plant extract in rats at 200 mg/kg and 400 mg/kg dose. Indomethacin (10 mg/kg) is used as reference standard. Serum levels of inflammatory markers and cytokines, hematological and serum hepatic enzyme indices were analyzed in granuloma-induced model. Results: The methanol extract suppressed Carrageenan-induced paw edema significantly at different time intervals. The highest percentage inhibition was observed at 3rd hr after Carrageenan injection, which was 42.67% and 49.33% for 200 mg/kg and 400 mg/kg dose of the extract respectively. In granuloma-induced model, the methanol extract at 200 mg/kg and 400 mg/kg dose inhibited exudate formation by 28.58% and 41.27%, respectively and inhibition of granuloma tissue was 32.45% and 43.71%, respectively along with significant decrement in serum C-reactive protein, Prostaglandin E2, Tumor necrosis factor-α, Interleukin-6 while increases in Interleukin-10 levels. Also, the results showed hematological and serum hepatic enzyme levels were rectified to near normal levels in treated rats. Conclusion: The outcome of the investigation reveals the potential of extract as possible anti-inflammatory agent, which can be develop into therapeutic agent or supplement and also necessitates further pharmacological studies on the plant.