Anti-Inflammatory Activity of 80% Methanol Leaf Extract of Urtica simensis Steudel (Urticacaeae) in Rodents

Abstract

The leaves of Urtica simensis Steudel (Urticacaeae) have long been used traditionally to cure a variety of diseases, including eye injuries, gonorrhea, erectile dysfunction, malaria and peptic ulcer disease. They are also claimed to have anti-inflammatory and wound-healing properties. However, there is no scientific evidence to back-up the traditional assertions. The aim of this study was to evaluate in vivo anti-inflammatory activity and to quantitatively determine the major chemical constituents of the 80% methanol leaf extract of U. simensis. The anti-inflammatory activity was evaluated at doses of 100, 200 and 400 mg/kg of the leaf extract using acute model of inflammation (carrageenan induced hind paw oedema) and chronic model of inflammation (cotton pellet induced granuloma) in rats. U. simensis leaf extract had a statistically significant effect on the carrageenan-induced paw oedema and cotton pellet-induced granuloma models. The 400 mg/kg dose demonstrated maximum percent of inhibition of oedema i.e. 27.61% and 35.42%; p < 0.001 at 3rd and 4th h of post-induction, respectively, which is comparable to indomethacin. All the tested doses showed significant (p < 0.001) exudate and granuloma inhibition in cotton pellet induced granuloma model. Phytochemical analysis revealed total values of 26.70 ± 0.14 mg GAE/g of dry weight of extract for phenolic compounds, 13 ± 0.18 mg QE/g of dry weight of extract for flavonoids, and 17.06 ± 0.11 mg AE/g of dry weight of extract for alkaloids in the 80% methanolic leaf extract of U. simensis. Data obtained from the present study generally justified that the 80% methanol leaf extract of U. simensis had significant anti-inflammatory activities, supporting the folkloric use of the plant.