PTGS2 and rheumatoid arthritis: As an anti-inflammatory, curcumin causes downregulation of NF-kB, cyclooxygenase 2 (COX2) and pro-inflammatory cytokines such as interleukin-1 (IL-1 and IL-6) and TNF-α and showed high efficacy against rheumatoid arthritis, psoriasis, and post-operative inflammation [100].