Inner anti-inflammatory mechanisms of petroleum ether extract from Melilotus suaveolens ledeb

Melilotus suaveolens Ledeb is a species of traditional medical plant for treating inflammation-related disease. This study is to explore the inner anti-inflammatory mechanism on petroleum ether extract from Melilotus suaveolens Ledeb. Materials and Methods. Inflammatory cellular model was founded by intervention of lipopolysaccharide (LPS) on RAW264.7 cell line. Secretion of TNF-alpha, IL-1 beta, IL-6, NO and IL-10 in supernatant, mRNA expression of TNF-alpha, COX-2, iNOS and HO-1, protein expression of COX-2 and HO-1, activation of NF-kappa B and ingredients in the extract were assayed. Results. The extract could not only reduce production of pro-inflammatory mediators by blocking NF-kappa B activation but promote release of anti-inflammatory mediator HO-1 significantly. The only active ingredient in the extract was coumarin and the concentration of coumarin in each 1 g extract was 0.27822 mg. Conclusion. Compared to Dexamethasone, the extract not only has similar effects on antagonizing pro-inflammatory mediators and cytokines but has effects on promoting production of anti-inflammatory mediators.