Abstract Synovial hyperplasia is the main cause of chronic rheumatoid arthritis (RA). but the mechanism of synovial hyperplasia is still unclear. Etodolac (ETD) is a selective COX-2 inhibitor for relieving pain and stiffness in RA. but the disease modifying effect is still lack of evidence. https://parisnaturalfoodes.shop/product-category/herbatint-4m/