BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune diseased state, characterized by hyperplasia of the synovial membrane, degradation of cartilage, and bone erosion of diarthrodial joints. Kadsura heteroclita (Roxb) Craib (Schizandraceae), a traditional Tujia ethnomedicine called Xue Tong in China, has been long used for the prevention and treatment of rheumatic and arthritic diseases, especially in the southern China. This study aimed to evaluate anti-arthritic effects of the ethanol extract of Kadsura heteroclita stems (KHS) on complete Freund's adjuvant (CFA)-induced arthritis (A...