Abstract: Abstract: Objective To investigate the effect of moderate static magnetic fields (SMF) on secretion of inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) in human monocytic leukemic cell line THP- 1. Methods THP- 1 cells at logarithmic phase were divided into control group and magnetic treatment group. CCK-8 method was used to detect cell proliferation after THP-1 cells were exposed to 60 mT, 200 mT and 400 mT static magnetic fields at 18, 24 and 48 h. Then THP-1 cells were divided into control group, magnetic treatment group, LPS activation group and LPS+SMF treatment group. When magnetic treatment group and LPS+SMF treatment group were exposed to SMF at 18, 24 and 48 h, the levels of the cytokines TNF-α, IL-6 and IL-8 were determined by ELISA. Results (1)60 mT, 200 mT and 400 mT SMF had no significant effects on cell proliferation in THP-1 cells (P > 0.05). (2)THP-1 cells secreted more TNF-α and IL-6 in 24 h than 18 h in every group, while IL-8 didn′t change. Compared with 24 h, the secretion of TNF-α decreased and IL-6 didn′t change, while IL-8 increased in 48 h. At three sampled time THP-1 cells of LPS activation group secreted more TNF-α, IL-6, IL-8 than those of control group and magnetic treatment group. After magnetic treatment THP-1 cells of LPS+SMF treatment group secreted less TNF-α, IL-6, IL-8 than those of LPS activation group (P < 0.05). Conclusion Static magnetic field may have some inhibitory effects on release of TNF-α, IL-6, IL-8 from THP 1 cells, which can provide basic data for the treatment of rheumatoid arthritis.

Key words: rheumatoid arthritis, static magnetic field, THP-1 cells, inflammatory factors, LPS, ELISA, TNF-α, IL-6, IL-8