Analgesic and Anti-inflammatory Activities of Urena lobata L. Leaf Extracts

Pulutan (Urena lobata L.) is a medicinal plant that has been traditionally used to treat fever, infection, and inflammation. However, preclinical studies on its activity as an analgesic and anti-inflammatory agent are still limited. The present study was aimed at investigating the analgesic and anti-inflammatory activities of U. lobata leaf extracts, as well as predicting the biological properties of the active components. Eight (two control and six test) groups of male Wistar rats were used in this study. Water and ethanol were used to extract the leaves of U. lobata, and each prepared in doses of 125, 250, and 500 mg/kg body weight (BW) for the treatments. The antiinflammatory and analgesic activities of the extracts were evaluated. Following active compound identification using UHPLC-MS/MS, several compounds were analyzed for drug-likeness and ADME-T properties. The results revealed that both aqueous and ethanolic extracts of U. lobata at 125 and 250 mg/kg BW significantly (p < 0.05) inhibited paw edema with an area under curve (AUC) volume of 10 and 5%, respectively, compared to the control group. For analgesic activity, the aqueous extract of U. lobata was able to significantly (p < 0.05) increase the AUC for pain threshold by 30-100 % compared to the control group. However, the activity of the ethanolic extract was lower than the aqueous extract. The drug-likeness analysis indicated that all the phytoconstituents were within the range established by Lipinski's rule of five. Stigmasterol, ss-sitosterol, and mangiferin were predicted to have better ADME-T properties than that of the other compounds.