NFKB1 and gout: In the present study we demonstrated that in MSU crystal–induced rat model of gouty arthritis RPP15 (0.4, 0.8, 1.2 g/kg) significantly downregulated the inflammatory factors (TNF-α, IL-1β, and IL-8) levels in the knee synovial fluid, and immunohistochemistry analysis indicated RPP15 (0.4, 0.8, 1.2 g/kg) suppressed the expression of active NF-κB p65 in the synovium.