Objective:To study the preventive and therapeutic effects of the combination of Polygoni Cuspidati Rhizoma et Radix and Cinnamomi Ramulus(PC) on hyperuricemia

and its effect on urate-anion transporter 1(URAT1)

organic anion transporters 3(OAT3) and ATP-bindingcassette subfamily G member 2(ABCG2) in rats. Method:Eighty four male SD rats were randomly divided into 7 groups:the normal group

the model group

the benzbromarone (10 mg·kg-1) group

the Tongfengding capsule (160 mg·kg-1) group and PC compatibility low-

medium-and high-dose (3.5

7

14 g·kg-1) groups

with 10 rats in each group. The hyperuricemia model in rats was established through ip injection of potassium oxonate (200 mg·kg-1)

ig administration of hypoxanthine (50 mg·kg-1) and ethambutol (250 mg·kg-1). Since the fourth day

all the rats were intragastrically administered with drugs for 2 weeks

once a day

in order to determine their serum uric acid (SUA)

creatinine (Cr)

blood urea nitrogen (BUN)

glutamic-pyruvic transaminase (GPT)

as well as urinary uric acid (UUA) levels. The RT-PCR method was used to measure the mRNA levels of renal URAT1

OAT3 and intestinal ABCG2 in rats. Renal URAT1 and OAT3 protein expressions in rats were determined by Western blotting method. Intestinal ABCG2 protein expression in rats was assayed by immunohistochemistry method. Result:Compared to the normal group

SUA levels of the model group increased significantly and excretion of UUA decreased

with high expressions of renal URAT1 mRNA and protein

low expressions of renal OAT3 and intestinal ABCG2 mRNA and protein expression. The results between the normal group and the model group showed significant statistical differences (P<0.01). Compared to the model group

PC medium-dose and high-dose groups showed significantly reduction in SUA and BUN levels

and increase in 24 h excretion of uric acid. PC medium-dose and high-dose groups showed inhibition in renal URAT1 mRNA and protein levels

and increase in renal OAT3 and intestinal ABCG2 mRNA and protein levels. The results between the two groups showed significant statistical differences (P<0.05

P<0.01). Conclusion:PC has an obvious effect of anti-hyperuricemia. It may down-regulate the expression of renal URAT1 and up-regulate the expressions of renal OAT3 and intestinal ABCG2 in rats to reduce re-absorption of uric acid and increase the excretion of uric acid.