Anti-hyperuricemic and nephroprotective effects of Modified Simiao Decoction in hyperuricemic mice

Modified Simiao Decoction (MSD), based on clinical experience, has been used for decades and famous for its efficiency in treating hyperuricemic and gouty diseases. To investigate the effects of MSD on anti-hyperuricemic and nephroprotective effects are involved in potassium oxonate-induced hyperuricemic mice. The effects of MSD were investigated in hyperuricemic mice induced by potassium oxonate. MSD were fed to hyperuricemic mice daily at a dose of 0.45, 0.90, 1.80 g/kg for 10 days, and allopurinol (5 mg/kg) was given as a positive control. Serum and urine levels of uric acid and creatinine, and fractional excretion of uric acid (FEUA) were determined by colorimetric method. Its nephroprotective effects were evaluated by determining a panel of oxidative stress markers after the intervention in hyperuricemic mice. Simultaneously, protein levels of urate transporter 1 (URAT1) and organic anion transporter 1 (OAT1) in the kidney were analyzed by Western blotting. MSD could inhibit XOD activities in serum and liver, decrease levels of serum uric acid, serum creatinine and BUN, and increased levels of urine uric acid, urine creatinine, FEUA dose-dependently through down-regulation of URAT1 and up-regulation of OAT1 protein expressions in the renal tissue of hyperuricemic mice. It also effectively reversed oxonate-induced alterations on renal MDA levels and SOD activities in this model. MSD processes uricosuric and nephroprotective actions by regulating renal urate transporters and enhancing antioxidant enzymes activities to improve renal dysfunction in hyperuricemic mice.