TNF and rheumatoid arthritis: It has been reported that GFD could substantially inhibit the activities of interleukin-6 and tumor necrosis factor-α in the serum of adjuvant-induced arthritis rats, as well as inhibit the formation of synovitis and pannus, and has obvious therapeutic effect on rheumatoid arthritis (He and Gu, 2008; Xia and Song, 2011).