Therapeutic Effect of Matrine on Collagen-Induced Arthritis Rats and Its Regulatory Effect on RANKL and OPG Expression

OBJECTIVE: To investigate the effect of matrine on rats with collagen-induced arthritis (CIA) and its regulatory effect on receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) expression. METHODS: Wistar rats (n = 6) and CIA rats (n = 30) were randomly divided into six groups: healthy, CIA control, low/medium/high matrine (25, 50, or 100 mg/kg, once per day for six weeks), and methotrexate (MTX) (2 mg/kg, once per week for six weeks). The degree of joint damage was evaluated by X-ray and HE staining. Bone marrow suppression was assessed by routine blood analysis. In addition, the levels of serum RANKL and OPG in the rats were measured by ELISA. RESULTS: The level of joint swelling and degree of joint damage assessed by ankle swelling measurements, AI score, X-ray, and HE staining were alleviated in the CIA rats treated with MTX or different doses of matrine. Furthermore, no obvious inhibitory effect was observed on the bone marrow of the CIA rats, regardless of the dose of matrine or treatment with 2 mg/kg MTX (P > 0.05). The levels of OPG in serum and the ratio of OPG/RANKL were higher, and RANKL expression was lower in the low/medium/high matrine group compared with that of the CIA control group. The serum levels of OPG and OPG/RANKL ratio increased with the matrine dose, while the opposite was observed for RANKL expression. CONCLUSION: Matrine treatment was associated with a lower degree of bone destruction, increased OPG expression and OPG/RANKL ratio, and decreased RANKL expression in CIA rats. Thus, matrine may represent a novel drug candidate for the treatment of RA.