Objective: To investigate the effect of Guizhi Shaoyao Zhimu Tang(GT) on inflammatory signal expression in synovial tissues of joint of rats with monosodium urate crystal-induced gouty arthritis(GA). Method: Totally 180 male SD rats were randomLy divided into 3 experiments[the Immunohistochemistry

enzyme linked immunosorbent assay(ELISA)

Western blot experiment] with 60 rats each experiment divided into 6 groups with 10 rats each group according to weight.The high

medium and low dose group of GT (4

8

16 g·kg-1)and colchicine group (3×10-4 g·kg-1) were treated with medicine by gastric administration

the normal and model group were given equal volume of distilled water. Medicine or distilled water was given once daily for seven consecutive days throughout the experiment.On the fifth day

GA model was made by injection of monosodium urate in the ankle joint cavity of rat.The synovial tissues of the rats were taken and expression of nod-like receptor protein 3(NLRP3) inflammasomes were detected with immunohistochemistry and integrated absorbance(IA) was measuring with Image-Pro Plus 6.0 analysis system. The expression levels of apoptosis-associated speck-like protein containing a CARD(ASC)

Caspase-1 signaling proteins were detected by Western blot. Expression of inflammatory cytokine such as interleukin-1 beta (IL-1β) and interleukin-6 (IL-6)

tumor necrosis factor alpha (TNF-α)

nuclear factor-κB (NF-κB) were detected with ELISA. Result: Compared with normal group after 72 hours

the expression of NLRP3 inflammasomes

ASC

Caspase-1 and IL-1β

IL-6

TNF-α

NF-κB in synovial tissues of the joint of GA rats significantly increased(P<0.05)

whereas Caspase-12 significantly decreased(P<0.05). the expression of NLRP3 inflammasomes

ASC in medium and high dose group of GT and Caspase-1 in all group of GT significantly decreased than the model group(P<0.05)

whereas Caspase-12 increased(P<0.05) and there was significant decreasing change in IL-1β

IL-6

TNF-α

NF-κB in all dose group of GT. Conclusion: The acion mechanism of GT on GA in rats is related to decreasing the expression levels of NLRP3

ASC and Caspase-1 and increasing the expression of Caspase-12

and accordingly inhibiting the maturation of IL-1β and the activation of NF-κB

reducing the expression of inflammatory factors in NLRP3 inflammasomes signaling pathway.