Anti-inflammatory and anti-arthritic effects of Guge Fengtong Formula:in vitro and in vivo studies

Rheumatoid arthritis (RA) is the most common inflammatory arthritis and a major cause of disability. Presently, the clinical therapeutic medicines for inflammatory and arthritic diseases are unsatisfactory due to severe adverse effects or ineffectiveness. The Guge Fengtong formula (GGFT), containing the standardized extracts of Dioscoreae Nipponicae Rhizoma, Spatholobi Caulis, and Zingiberis Rhizoma, has long been used for RA treatment in China. However, the detailed anti-inflammatory and anti-arthritic activity of GGFT has not been reported so far. In the present work, we aimed to evaluate the anti-inflammatory and anti-arthritic effects of GGFT using three in vivo animal models and tried to uncover the underlying mechanism of action in RAW 264.7 macrophages. The obtained results indicated that GGFT significantly attenuated ear edema, decreased carrageenan-induced paw edema, reduced the arthritis score, and reversed the weight loss of the complete Freund's adjuvant (CFA)-injected rats. Additionally, decrease in synovial inflammatory infiltration and synovial lining hyperplasia in the joints and decline of inflammatory factors (TNF- and IL-1) in the serum were observed in the GGFT-treated rats. In lipopolysaccharide-activated RAW264.7 macrophages, GGFT reduced the production of NO, PGE2, and IL-6 and inhibited the expression of iNOS, COX-2, and NF-B. Our results demonstrated that GGFT possessed considerable anti-inflammatory activity and had potential therapeutic effects on adjuvant induced arthritis in rats, providing experimental evidences for its application in the treatment of RA and other inflammatory diseases.