Inhibitory Effect of Water-soluble Total Saponin of Rhizoma Dioscoreae Nipponicae on Nuclear Factor-kappa B p65 in Fibroblast-like Synoviocytes of Rheumatoid Arthritis Patients

Objective To observe the effect of water-soluble total saponin of Rhizoma Dioscoreae Nipponicae(RDN) on protein levels and mRNA contents of nuclear factor-kappa B(NF-κB) p65 and its inhibition factor IκB-α in fibroblast-like synoviocytes of rheumatoid arthritis patients in vitro. Methods Fibroblast-like synoviocytes of rheumatoid arthritis patients were cultured, and then were divided into four groups, namely 10,20 and 30 mg / L water-soluble total saponin of RDN groups, model group and blank control group. The levels of NF-κB and IκB-α protein were assessed by Western blotting method and their mRNA expression levels were measured by semi-quantitative RT-PCR method. Results The activation of NF-κB in fibroblast-like synoviocytes was significantly inhibited in the three RDN groups, and the protein and gene levels of NF-κB were obviously decreased(P0.05, compared with those in the model group), while the protein and gene levels of IκB-α were increased(P0.05). Conclusion Water-soluble total saponin of RDN can effectively inhibit the expression of nuclear transcription factor in fibroblast-like synoviocytes of rheumatoid arthritis patients, which may be one of the therapeutic mechanisms of RDN for rheumatoid arthritis.