Immunomodulatory Effects of Bee Venom in Human Synovial Fibroblast Cell Line

As in Iranian traditional medicine, bee venom (BV) is a promising treatment for the rheumatoid arthritis (RA) which is considered as a problematic human chronic inflammatory disease in the present time. Smoking is considered to be a major risk factor in RA onset and severity. The main aim of this study is to investigate the effects of BV on cigarette smokeinduced inflammatory response in fibroblast-like synoviocytes (FLS). Cytotoxicity of cigarette smoke condensate (CSC) and bee venom were determined by the tetrazolium (MTT) method in cultured synovial fibroblastes. The expression of interleukin-1β and sirtuin1 mRNA were analyzed by SYBR green real-time quantitative PCR. Differences between the mean values of treated and untreated groups were assessed by student t-test. Based on MTT assay, CSC and BV did not exert any significant cytotoxic effects up to 40 μg/mL and 10 μg/mL, respectively. Our results showed that interleukin-1β mRNA level was significantly up-regulated by CSC treatments in LPS-stimulated synoviocytes in a dose-dependent manner. Conversely, the expressions of IL-1β and Sirt1 were up-regulated even in lower concentrations of BV and attenuated at higher concentrations. Also, BV attenuated the CSC-induced and LPS-induced inflammatory responses in synovial fibroblasts. Our results support the epidemiological studies indicating pro-inflammatory effects of CSC and anti-inflammatory effects of BV on FLS cell line.