Formulation of a novel herbal emulgel using Leea indica (Burm.f.) Merr. (Burulla/Gurulla) leaf extract and evaluation of in vitro anti-inflammatory and antioxidant activities

Abstract

Many topical anti-inflammatory formulations available in the commercial market have limited patient preference due to their unfavorable adverse effects and less effectiveness. The aim of the present study was to formulate a novel herbal emulgel using Leea indica (Burm.f.) Merr. (Burulla/Gurulla) leaves grown in Sri Lanka and, evaluate in vitro anti-inflammatory and antioxidant activities. Different formulations (Fg1-Fg6) were prepared by incorporating freeze dried powder of 70% aqueous acetone leaf extract. All formulations were tested for their physicochemical stability parameters for 30 days, and they were subjected for in vitro anti-inflammatory activity (by Human Red Blood Cell membrane stabilization assay) and in vitro antioxidant activity (by 2, 2-diphenyl-1-picrylhydrazyl; DPPH) assay respectively. Among the formulated herbal emulgels, Fg6 showed the significantly high values of percentage inhibition (93.734 ± 0.895 %) compared to the positive control (62.575 ± 0.644 %) of heat induced hemolysis of erythrocytes at the concentration of 12.5 mg/ mL. In vitro antioxidant activity of Fg6 and positive control were 3.386 ± 0.007 and 0.364 ± 0.004 mMol Trolox per 100g of emulgel respectively. All formulations were found to be semi-solid, homogenous, washable with water, having no phase separation and pH in the range of 6 to 7. There was no remarkable variation of stability parameters tested during 30 days. It is concluded that the formulated herbal emulgels have promising anti-inflammatory and antioxidant activities and formulation Fg6 can be commercialized as a novel herbal emulgel.