Efficacy of Xixiancao (Herba Siegesbeckiae Orientalis) on interactions between nuclear factor kappa-B and inflammatory cytokines in inflammatory reactions of rat synovial cells induced by sodium urate.

Objective: To investigate the interaction between nuclear factor kappa-B (NF-κB) and inflammatory cytokines in synovial cell inflammatory responses induced by sodium urate, and to evaluate the efficacy of Xixiancao (Herba Siegesbeckiae Orientalis) on these interactions.

Methods: The interactions between NF-κB and inflammatory cytokines/mediators in synovial cells in acute gouty arthritis were investigated. We observed the expressions of NF-κB, interleukin (IL)-1β, IL-8, and tumor necrosis factor alpha (TNF-α) in synovial cells at different timepoints in an in vitro model of synovial cell inflammatory responses induced by sodium urate and in an in vivo model of gouty arthritis. Changes in the expressions of NF-κB, IL-1β, IL-8, and TNF- in synovial cells of all experimental groups were compared and observed after treatment with different doses of Xixiancao (Herba Siegesbeckiae Orientalis) and colchicine. The interactions between NF-κB and IL-1β, IL-8, and TNF-α were analyzed. Pathological changes in synovial tissues were observed in rats with acute gouty arthritis.

Results: Compared with the blank group, the expression levels of NF-κB, IL-1β, IL-8, and TNF-α were increased significantly at different timepoints in the in vitro model of synovial cell inflammatory responses induced by sodium urate, and in the in vivo model of gouty arthritis. Compared with the model group, the expressions of NF-κB, IL-1β, IL-8, and TNF-α in synovial cells induced by sodium urate were decreased in the different Xixiancao (Herba Siegesbeckiae Orientalis) dose groups and the colchicine group. The effect was more obvious in the high dose Xixiancao (Herba Siegesbeckiae Orientalis) group. The expression of NF-κB in synovial cells was positively correlated with the expressions of IL-1β, IL-8, and TNF-. Histopathological examination of synovial tissues in the high dose Xixiancao (Herba Siegesbeckiae Orientalis) group and Colchicine group showed that the characteristics of acute gouty arthritis were reduced, and there was a trend towards a positive correlation between NF-κB and inflammatory cytokine expressions.

Conclusion: The activation of NF-κB is associated with the activation of IL-1β, IL-8, and TNF-α during the pathogenesis of acute gouty arthritis, leading to the continuation and enhancement of the inflammatory response. Expressions of IL-1β, IL-8, and TNF-α in synoviocytes during acute gouty arthritis effectively inhibit local inflammation.