As it has been reported that IFN-γ is positively correlated with the severity of RA, we used LPS and IFN-γ in our study to stimulate primary bone marrow-derived macrophages and peritoneal elucidated macrophages to mimic macrophage activation in RA, and we found that PPI significantly suppressed inflammatory cytokines and mediator expression in this system, suggesting an anti-inflammatory potential of PPI. Here, IFNG is linked to rheumatoid arthritis.