Guizhi-Shaoyao-Zhimu decoction possesses anti-arthritic effects on type II collagen-induced arthritis in rats via suppression of inflammatory reactions, inhibition of invasion & migration and induction of apoptosis in synovial fibroblasts

Background: Rheumatoid arthritis (RA) is a known intractable chronic inflammatory disease of synovial joints characterized by hyperplasia and consecutive inflammation with a high prevalence.Guizhi-Shaoyao-Zhimu (GSZD) is the first choice for clinical treatment of RA in Chinese traditional medicine. This study is aimed to explore the possible pharmacological mechanisms of anti-arthritic effect of GSZD. Methods: Type II collagen-induced arthritis (CIA) rat model was used to study the anti-arthritic activity of GSZDin vivo, and toe swelling & arthritis score, serum levels of cytokines, and pathological examinations were carried out. In vitro, TNF-alpha induced MH7A cells were used to study the possible mechanisms of GSZD. The antiproliferative effects of GSZD were determined by MMT assay, and pro-apoptotic activity of GSZD in MH7A cells was determined by flow cytometry analysis & DAPI staining. Furthermore, the adhesive and invasive abilities of MH7A cells were determined using cell adhesion and transwell assays. MMPs levels were determined by ELISA assays, and mRNA expressions of Caspase-3, -9, Bax, SOCS1, Bcl-2, JAK2, STAT-3 and -5 were determined using qRT-PCR analysis. Besides, the major chemical components in GSZD were analyzed by HPLC-QqQ-MS analysis. Results: Our results showed GSZD reduced the toe swelling & arthritis score, and serum levels of TNF-alpha, IL-1 beta, IL-6 & IL-17a in CIA rats; pathological examination results indicated GSZD improved ankle joint injury in CIA rats./n vitro, GSZD showed significant anti-proliferative and pro-apoptotic effects on TNF-a stimulated MH7A cells. After GSZD treatment, the adhesive and invasive abilities of MH7A cells were reduced, and secretions of MMPs, IL-6 and IL-8 were also reduced. GSZD decreased the releases of TNF-alpha and IL-1 beta in LPS stimulated RAW 264.7 cells. Further studies showed GSZD up-regulated mRNA expressions of Caspase-3, -9, Bax, and SOCS1, whereas down-regulated mRNA expressions of Bcl-2, JAK2, STAT3 and STATS. Besides, 13 major chemical components were identified in GSZD extracts through HPLC-QqQ-MS analysis. Conclusion: Our results suggested GSZD possesses an anti-rheumatic effect on CIA rats, and the possible mechanism is related to inhibiting inflammatory response, inhibiting invasion and migration of synovial fibroblasts, and inducing apoptosis in synovial fibroblasts.