Regulatory effects of Paeoniflorin on G protein-coupled signaling of synoviocytes in collagen-induced arthritis rats / 中国药理学通报

ABSTRACT

Aim To investigate the regulatory effects of Paeoniflorin on G protein-coupled signaling by synoviocytes of collagen-induced arthritis (CIA) rats. Methods CIA was induced by chicken type Ⅱcollagen. Pae (25, 50, 100 mg?kg-1) was administered to CIA rats from d 16 to d 23 after immunization. Arthritis was evaluated by hind paw swelling and arthritis index. Expression of inhibitory G protein (Gi) was detected by Western blotting technique. The level of cAMP in synoviocytes was measured by radioimmunoassay. Protein kinase A (PKA) activity was assessed by Kinase-Glo Luminescent Kinase Assay. Results There was remarkably secondary inflammation in CIA rats. The expression of Gi in synoviocytes increased. While cAMP level and PKA activity of synoviocytes decreased. The inflammatory responses of CIA rats were inhibited after administration of Pae. At the dose of 100 mg?kg-1, Pae reduced Gi expression. cAMP level and PKA activity were enhanced by Pae at the doses of 50 and 100 mg?kg-1 respectively. In ivtro, Pae (2.5, 12.5, 62.5 mg?L-1) reduced Gi expression, but enhanced the level of cAMP and PKA activity. Conclusion G protein-coupled signaling was associated with the pathogenesis of synovitis in CIA rats. Pae has anti-inflammatory effects on CIA rats by modulating G protein -coupled signaling.