Hypouricemic and Nephroprotective Effects of an Active Fraction from Polyrhachis Vicina Roger On Potassium Oxonate-Induced Hyperuricemia in Rats.

BACKGROUND/AIMS: The objective of this study is to evaluate the hypouricemic and nephroprotective effects of an active fraction from Polyrhachis vicina Roger (AFPR) in potassium oxonate-induced hyperuricemic rats.

METHODS: Hyperuricemia was induced by potassium oxonate in male rats. AFPR was orally administered to hyperuricemic rats for 12 consecutive weeks. Serum, liver and kidney samples were collected for effects and mechanism analysis. The levels of serum uric acid (SUA) were measured by the phosphotungstic acid method, xanthine oxidase (XOD) activity in the hepatic and serum samples were measured by ultraviolet spectrophotometry, serum levels of interleukin-1 (IL-1β), interleukin-1 (IL-6) and tumor necrosis factor-α (TNF-α) were measured by ELISA, the levels of serum creatinine (SCr), blood urea nitrogen (BUN), super oxide dismutase (SOD) and malondialdehyde (MDA) in serum were determined by colorimetric method. Protein expression of renal URAT1, GLUT9, and OAT1 were analyzed by Western blot.

RESULTS: AFPR significantly decreased the levels of SUA, serum and hepatic XOD, SCr, BUN, and MDA as well as increased SOD. In addition, AFPR treatment significantly reduced the levels of proinflammatory cytokines in serum, including IL-1β, IL-6 and TNF-α. Moreover, we found the significant decrease in protein expression of URAT1 and GLUT9, and the significant increase in protein expression of OAT1 in the kidney in AFPR treated groups compared to the model groups of hyperuricemia.

CONCLUSION: These findings suggest that AFPR has anti-hyperuricemic activity attributed to the inhibition of uric acid generation in the liver and probably to the enhancement of urate excretion in the kidney, and possess nephroprotective effect in hyperuricemic rats due to its anti-inflammatory and antioxidant activities.