ABSTRACT
Objective::To study the therapeutic and inflammatory effects of gentiopicroside(GPS) on adjuvant-induced arthritis (AA) rats. Method::The 36 male SD rats were randomly divided into six groups, namely the model group, GPS groups (low, medium and high dose), and the methotrexate (MTX) group, with six rats in each group. AA rats were induced through intradermal injection with 0.1 mL complete Freund's adjuvant (CFA) into the right hind paw, except the normal group. After modeling, rats in each group were treated with drugs for 7 days, once a day. The doses were 30, 60, 120 mg·kg-1 in the GPS groups, and 0.2 mg·kg-1 in the MTX group. The normal group and the model group were intragastrically treated with the same volume of normal saline. During the experiment, the paw thickness and paw volume of rats were recorded everyday by the digital vernier calipers and the toe volume measuring instrument. On the seventh day, X-ray and histopathological examination of the ankle joints were performed by the small animal living imaging instrument and hematoxylin eosin stain. Blood samples were collected from the abdominal aorta at the end of the experiment to determine the levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in serum by enzyme-linked immunosorbent assay(ELISA) kits. The mRNA levels of IL-6 and TNF-α in synovial tissues were determined by Real-time fluorescent quantitative polymerase chain reaction(Real-time PCR). Result::Compared with the normal group, the results of each index in the model group were significantly different (P<0.01). Compared with the model group, the results of paw volume and paw thickness decreased significantly (P<0.01), TNF-α level decreased significantly (P<0.01), and IL-6 and TNF-α mRNA levels decreased significantly (P<0.05, P<0.01) in drug treated groups. The results of X-ray and histopathological examinations indicated that GPS had a protective effect on the ankle joints of AA rats. Conclusion::GPS has the therapeutic effect on AA rats by inhibiting levels of proinflammatory cytokines in serum and relevant mRNA levels in synovial tissues.