Modified Si-Miao-San Extract Inhibits the Release of Inflammatory Mediators from Lipopolysaccharide-Stimulated Mouse Macrophages

ETHNOPHARMACOLOGICAL RELEVANCE: Modified Si-Miao-San (mSMS) is a prescription modified from Si-Miao-San which is an ancient Chinese prescription used to treat various ailments. AIM OF THE STUDY: Modified Si-Miao-San (mSMS) has been used for the treatment of infectious and inflammatory disorders in the clinic. This study was aimed to investigate its anti-inflammatory activity and underlying mechanism at cellular and molecular levels. MATERIALS AND METHODS: We stimulated RAW264.7 cells with Lipopolysaccharide (LPS) and observed effects of mSMS on the release of inflammatory mediators such as: tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), NO, and relative gene expressions. Meanwhile, we also investigated the modulation of mSMS in inflammatory signal transduction mediated through extracellular signal-regulated protein kinase (ERK) and nuclear factor-kappaB (NF-kappaB) pathway. RESULTS: Our findings demonstrated that mSMS significantly inhibited the excessive production of NO, TNF-alpha and IL-6 and the over expression of relative genes in LPS-stimulated macrophages. In addition, mSMS suppressed LPS-induced ERK1/2-phosphorylation and inhibited the activation of NF-kappaB by attenuation of I kappaB-alpha degradation. CONCLUSIONS: Our results suggest that the anti-inflammatory properties of mSMS might result from the inhibition of inflammatory mediators, such as NO, TNF-alpha and IL-6, via suppression of ERK and NF-kappaB dependent pathways.