Anti-inflammatory effect of Sanshuibaihu decoction may be associated with nuclear factor-[kappa]B and p38 MAPKa in collagen-induced arthritis in rat

Sanshuibaihu decoction (SSBH) is an anti-arthritic Chinese herbal formula which has been used in the treatment of rheumatoid arthritis (RA) for many years. We herein aimed to confirm its anti-arthritic effect and explore the potential mechanism of action on collagen-induced arthritis (CIA) in rats. CIA was induced by immunizing 50 female Wistar rats with bovine type II collagen. 13 days following the immunization rats with CIA were treated with SSBH (50 mg/kg), leflunomide (LEF) (10 mg/kg) and physiological saline for 30 days, and rats without CIA were left untreated. After the treatment, paw edema was obviously improved in SSBH-treated rats, with the significant difference of arthritis score (F = 6.032, P = 0.006) observed between the three treated groups. In pathological observation, SSBH-treated rats showed a significant improvement of inflammatory infiltration, synovial hyperplasia, cartilage and bone destruction and joint fusion. After the treatment of SSBH, radiological score of knee (t = 11.504, P = 0.000) and ankle joints (t = 9.250, P = 0.000) was decreased significantly. In situ hybridization on joint tissue section indicated only slight synovial hyperblastosis and expression of NF-[kappa]B in SSBH-treated rats. Image analysis indicated a significant difference of means of integrated optical density (MIOD) (F = 3.956, P = 0.040) and means of stained area (MSA) (F = 3.867, P = 0.032) of NF-[kappa]B between the three treated groups. MIOD and MSA of SSBH-treated group were significantly lower vs control. Enzyme linked immunosorbent assay (ELISA) showed a significant difference (F = 10.167, P = 0.000) of the amount of p-p38 MAPKa in the three treated groups. The detected amount of p-p38 MAPKa in SSBH-treated group was significantly lower vs control. These results show SSBH has an inhibiting effect on CIA, which may be associated with NF-[kappa]B and p38 MAPKa.