Evaluation of anti-inflammatory and gastric anti-ulcer activity of Phyllanthus niruri L. (Euphorbiaceae) leaves in experimental rats

BACKGROUND The medicinal plants signify a massive basin of potential phytoconstituents that could be valuable as a substitute to allopathic drugs or considered as an analogue in drug development. Phyllanthus niruri L. (Euphorbiaceae) is generally used in traditional medicine to treat ulcer and inflammation. In this project we investigated the methanolic extract of leaves of Phyllanthus niruri for anti-inflammatory and anti-ulcer activity. METHODS The anti-inflammatory activity of methanol extract of Phyllanthus niruri leaves was evaluated at the doses of 100, 200 and 400 mg/kg, p.o. while using ibuprofen (20 mg/kg, p.o) as the standard drug. The animals used were Swiss albino rats. Inflammation was induced by injecting 0.1 ml carrageenan (1% w/v) into the left hind paw. Paw tissues from the different groups were examined for inflammatory cell infiltration. On the other hand, antiulcer activity of methanolic extract of P. niruri leaves at the doses of 100, 200 and 400 mg/kg, p.o. were examined against ethanol-acid induced gastric mucosal injury in the Swiss albino rats - keeping omeprazole (20 mg/kg, p.o.) as reference. The rats were dissected and the stomachs were macroscopically examined to identify hemorrhagic lesions in the glandular mucosa. RESULTS P. niruri significantly (p < 0.01) decreased carrageenan-induced paw edema; it exhibited a reduction of 46.80%, 55.32% and 69.14% at doses of 100, 200 and 400 mg/kg, respectively. These findings were further supported by the histological study. The methanolic extract also disclosed good protective effect against ethanol-acid induced gastric mucosal injury in the rats. Administration of the extract's doses (100, 200 and 400 mg/kg) demonstrated a significant (p < 0.01) reduction in the ethanol- acid induced gastric erosion in all the experimental groups when compared to the control. The methanolic extract at the higher dose (400 mg/kg) resulted in better inhibition of ethanol-acid induced gastric ulcer as compare to omeprazole (20 mg/kg). Histological studies of the gastric wall revealed that toxic control rats revealed mucosal degeneration, ulceration and migration of numerous inflammatory cells throughout the section. On the other hand, MEPN treatment groups showed significant regeneration of mucosal layer and significantly prevented the formation of hemorrhage and edema. CONCLUSIONS The investigation suggests that methanolic extract of P. niruri leaf possess anti-inflammatory activity and promotes ulcer protection as ascertained by regeneration of mucosal layer and substantial prevention of the formation of hemorrhage and edema.