The Experimental Study Of Genistein Treatment In A Rat Model Of Collagen Type â…¡-induced Arthritis And Its Potential Mechanisms

Objectives:To investigate the therapeutic effects and the potential mechanisms of genistein (Gen) alone, methotrexate (MTX) alone, or Gen plus MTX on rats with collagen type Ⅱ-induced arthritis (CIA).Subject:Sprague Dawley rats.Methods:At first, forty SD rats were randomly divided into normal group, model group, Gen treatment group, MTX treatment group, and Gen plus MTX treatment group (n=8). Model group and treatment group were established CIA model in Sprague-Dawley rats immunized with collagen type Ⅱ combined with complete Freund’s adjuvant (CFA). On the second day after immunization,1ml of suspension of Gen (30mg/kg body weight, once daily), MTX (0.2mg/kg body weight, once a week), or Gen plus MTX were administered orally to rats of treatment group, respectively. The rats in normal group and model group were administrated with normal saline in the same volume.Then, the arthritis was evaluated everyday by arthritis index (AI) and hind paw swelling. At the sixth week, the X-ray of joints was performed. After the rats were sacrificed, knee joints were harvested for detecting the microvessel density (MVD) of synovial membrane by immunohistochemical method, and the concentration of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor(VEGF), and matrix metallopeptidase (MMP)-1,2,9in serum was detected by Western blotting.Results:1. AI score, hind paw swelling, the X-ray image of joints, and the pathohistology of synovial tissue from knee joint of rats in the model group were shown obviously relative to those in the normal group (P<0.05), suggesting that the model of CIA rats induced by injection of collagen Ⅱ and CFA was established successfully.2. Our results showed that in vivo treatment of CIA-induced rats with Gen alone, MTX alone, or Gen plus MTX had great protective benefit at the arthritis index scores, hind paw swelling of rats and pathological synovial tissue in the treatment group compared with model control group, especially in Gen plus MTX treatment group, and no significant difference was observed between Gen and MTX treatment group.3. Therapeutic intervention with Gen and/or MTX in CIA rats resulted in a significant reduction of the synovial pannus formation and the expression of IL-1β, TNF-α, VEGF and MMP-1,2and9in serum of CIA rats (P<0.05).Conclusions:1. Our results suggest that Gen and/or MTX both have proven successful in ameliorating the course of arthritis in CIA rats, and combinational treatment of Gen with MTX demonstrated more effective regression than those in either Gen or MTX therapeutic CIA rats.2. The therapeutic effects of Gen and/or MTX on CIA rats might be performed to anti-inflammation through down-regulating the expression of IL-1β and TNF-a, and anti-angiogenesis by down-regulating the expressions of VEGF and MMP-1,2and9in serum of CIA rats.