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

Abstract

Pulutan (Urena lobata) is a medicinal plant used to treat fever, infection and swelling traditionally, although the pre-clinical study about the herbs as analgesic and anti-inflammatory are still limited. The objective of this study is to measure analgesic and anti-inflammatory activity of U. lobata leaf extract through in vivo study and in silico. This study was performed using male wistar rats divided into eight groups (two control groups and six test groups) (n=5). U. lobata leaf was extracted by water and ethanol, each prepared in dose of 125, 250, 500 mg/kg body weight. Anti-inflammatory activity was evaluated by plethysmometer for 6 hours, meanwhile analgesic activity was examined by analgesymeter for 4 hours. The data was analyzed using one way ANOVA test continued with LSD test (p < 0.05). Following active compound identification using Liquid Chromatography-Mass Spectra (LC-MS/MS), several compounds were used in an in silico study using docking server. Both aqueous and ethanolic extract of U.lobata at 125 and 250 mg/kg bw inhibited paw edema with an Area Under Curve (AUC) volume about 10 % and 5%, respectively, compared to control group (p<0.05). For analgesic activity, aqueous extract of U. lobata were able to increase the AUC for pain threshold of about 30-100 % compared to control group (p<0.05), whereas the activity of ethanolic extract lower than aqueous extract. Stigmasterol and beta-sitosterol in U. lobata potentially inhibited Cycloxygenase-2 (COX-2) as a pro-inflammatory mediator and pain. Aqueous and ethanolic extract of U. lobata have analgesic activity and anti-inflammation, the mechanism was predicted through inhibitory activity of COX-2.