IL17A and rheumatoid arthritis: Our results indicate that treatment of P. heterophyllum obviously reduces the levels of TNF-α, IL-1β, IL-6 and IL-17, and increases the expression of IL-4 and IL-10, implying that the anti-RA effect of P. heterophyllum is achieved to a certain extent via the inhibition of pro-inflammatory cytokines and the elevation of anti-inflammatory cytokines in AIA model rats.