Anti-inflammatory activity of extracts of Bushen-Qiangdu-Zhilv decoction, a Chinese medicinal formula, in M1-polarized RAW264.7

BACKGROUND Bushen-Qiangdu-Zhilv Decoction (BQZ) is one of famous traditional Chinese medical formula for treating ankylosing spondylitis (AS). However, the mechanisms underlying effects of BQZ remains unknown. Pro-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1, play an important role in AS. We therefore evaluated if BQZ could affect the expression of these cytokines. METHODS Crude extracts were prepared and fractioned with petroleum ether (PE), ethyl acetate (EA), n-butanol (BU) and finally water (ACE). The stability of the extracts was confirmed by high-pressure liquid chromatography (HPLC) analysis. M1-polarized RAW264.7 was induced and subsequently treated with BQZ extracts. Quantitative real-time PCR experiments were performed to measure mRNA expression of TNF-α and IL-1. RESULTS It was found that TNF-α could be significantly suppressed by ACE extracts, whereas IL-1 was dramatically inhibited by BU extracts, which was further confirmed by dose-dependent experiments. Importantly, MTS assays showed that both ACE and BU extracts had a low cytotoxicity. CONCLUSION Altogether, our study indicates that BQZ decoction exerts anti-AS effects via its anti-inflammatory activity and may have a low side-effect. Further analysis of the extracts of BQZ decoction could lead to a discovery of some novel drugs adding to therapeutic strategy for AS patients.