IL1B and Arthritis: By quantitative real-time PCR, mRNA levels of TNF-α, IL-1β, and IL-6 in synovium of AA rats turned out to be dramatically elevated with arthritis development in our CFA-induced arthritic rat model, while astilbin treatment caused a significant reduction of such cytokine profiles, especially with substantial effects on TNF-α and IL-6 (Figure 4(a)).