Therapeutic effects of gentiopicroside on adjuvant-induced arthritis by inhibiting inflammation and oxidative stress in rats

The purpose of this research was to evaluate the therapeutic effects of gentiopicroside (GPS) on adjuvant-induced arthritis (AA) rats. Rats were injected with complete Freund's adjuvant (CFA) for 0.1 mL in the right hind paw to induce AA. Thirty rats from three groups were treated with GPS (30, 60, 90 mg/kg) from day 15 to day 26. Arthritis was evaluated by arthritis index, paw volume, paw thickness, and X-ray. The effect of GPS on inflammation was assessed by measuring the levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6 and IL-17, as well as related mRNA. Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glutathione (GSH) protein carbonyl (PCO) and malondialdehyde (MDA) were measured to assess the effect of GPS on oxidative stress. These results indicate that GPS increases the levels of GSH-Px, SOD and GSH, and reduces the levels of MDA and PCO. GPS can significantly down-regulate the levels of IL-1β, TNF-α, IL-6 and IL-17, as well as related mRNA. In addition, X-ray and histopathological results show that GPS has a therapeutic effect on joints in AA rats. In summary, the therapeutic effects of GPS on AA rats are associated with anti-inflammation and antioxidation.