[Therapeutic effects of Hedyotis diffusa Willd. on type II collagen-induced rheumatoid arthritis in rats]

To investigate the therapeutic effects of Hedyotis diffusa Willd.on type Ⅱ collagen-induced rheumatoid arthritis in rats.

According to the random number table, 60 SD rats were divided into the normal control group (n=10, normal saline) and model group (n=50).The collagen-induced arthritis model was established with the injection of type Ⅱ collagen into the back in rats other than the normal group and evaluated by arthritis score, then the model rats were randomly divided into model group (normal saline), tripterygium wilfordii polyglycoside (GTW) 6 mg/kg group (daily dose:0.4 mg/kg), HD 3, 6, 12 g/kg groups (daily dose:3, 6 and 12 g/kg, respectively), with 10 rats in each group. The rats were treated with corresponding agents by intragastric administration.The arthritis index and the pain threshold of all rats at different time points were observed and measured weekly.After treated by intragastric administration for 28 days, all rats were killed to measure the changes of serum cytokine levels including interleukin 1β (IL-lβ), tumor necrosis factor a (TNF-a), prostaglandin (PGE₂), receptor activator for nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG).

Compared with the control group, the arthritis index and the serum levels of IL-lβ, TNF-a, PGE₂, RANKL, OPG and RANKL/OPG of the model group were increased significantly (P<0.05), the pain threshold of the model group was decreased significantly (P<0.05); compared with the model group, the arthritis index and the serum levels of IL-lβ, TNF-a, PGE₂, RANKL, OPG and RANKL/OPG of the GTW group, HD low-dose, medium-dose, high dose groups were decreased significantly (P<0.05), the pain threshold of the model group was increased significantly (P<0.05).

Hedyotis diffusa Willd.can significantly reduce arthritis index and increase pain threshold, reduce the level of IL-lβ, TNF-a, PGE₂, RANKL, OPG, and RANKL/OPG, then can prevent CIA effectively.