Effect of Rhizoma Polygoni Cuspidati and Ramulus Cinnamomi Compatibility on Uric Acid Metabolism and Urinary Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 in Rats with Hyperuricemia

Objective：To explore the effects of Rhizoma Polygoni Cuspidati and Ramulus Cinnamomicompatibility（PR） on uric acid metabolism and the expression of urinary neutrophil gelatinase-associated lipocalin（NGAL） and kidney injury molecule-1（KIM-1） in rats with hyperuricemia. Methods：Seventy male Sprague Dawley（SD） rats were randomly divided into 7 groups with 10 rats per group, including the normal group, model group, allopurinol group, benzbromarone group and PR groups at 3 doses（3.5, 7, 14 g/kg）. Except the normal group, rats of the other groups were intragastrically administered 100 mg/kg hypoxanthine and 250 mg/kg ethambutol, and subcutaneously injected with 200 mg/kg potassium oxonate. All rats were continuously modeled for 17 days, and gavaged with corresponding drugs. The rats of the normal and model groups were gavaged with saline, once a day, for 2 weeks. The levels of serum uric acid（SUA）, blood urea nitrogen（BUN） and creatinine（Cr） were determined. In addition, the contents of NGAL and KIM-1 in urine and the m RNA and protein expressions of xanthine oxidase（XOD） in liver of hyperuricemia rats were measured by reverse transcription polymerase chain reaction（RT-PCR） and Western blot, respectively. Moreover, the pathological changes of kidney were analyzed by hematoxylin and eosin（HE） stain method. Results：Compared with the normal group, the levels of SUA, BUN, NGAL and KIM-1 and the expressions of hepatic XOD m RNA and protein in the hyperuricemia rats were increased significantly（P〈0.01）. PR significantly decreased the levels of SUA, BUN, NGAL and KIM-1 and down-regulated the m RNA and protein expressions of hepatic XOD（P〈0.05 or P〈0.01）. In addition, the pathological changes of kidney were significantly suppressed by oral administration of PR. Conclusions：PR ameliorated uric acid metabolism and protected renal function, the underlying mechanism was mediated by decreasing the levels of SUA, BUN, NGAL and KIM-1, inhibiting the expression of hepatic XOD and ameliorating the pathological change of kidney.