OBJECTIVETo observe the changes of behavior and amino acids in brain tissue of rats with adjuvant arthritis, and effects of Xinfeng Capsule (XFC) on them.

METHODSAA model was induced by complete Freund's adjuvant in rats. Five groups including the normal control group, the model group, the XFC group, the methotrexate (MTX) group and the Tripterygium wilfordii polysaccharide (TPT) group were set up. The changes of behavior, amino acids in brain tissue, swelling degree of joints, and arthritis index (AI) were observed and the correlation analysis on these indexes was performed.

RESULTSCompared with those in the normal control, the frequency of independent activity obviously decreased in the model rats, accompanied with increased number of step-down errors, shortened step down latency (SDL) and prolonged escape latency (EL), also the level of gamma-aminobutyric acid (GABA) in brain tissue elevated and glutamic acid (GLU)/GABA reduced (P <0.05). Compared with those in the model group, all the above indexes were improved significantly in the XFC group after treatment (P <0.05), while they changed insignificantly in the MTX and TPT groups (P> 0.05), the degree of joint swelling and AI were obviously lower in the 3 treated groups (P< 0.05). Correlation analysis showed the frequency of independent activity and SDL were negatively correlated to the swelling degree of joint, and levels of AI, glycine (GLY) and GABA respectively, but positively correlated with GLU/GABA (P<0.05); while EL and number of step-down errors were positively correlated to AI, GLY and GABA respectively, but negatively correlated to GLU/GABA (P < 0.05).

CONCLUSIONImmune stress could lead to the changes of rat behavior and amino acids in brain tissue. XFC treatment could improve the behavior of AA rats through regulating the levels of amino acids in brain tissue.