Uric acid lowering effect of Tibetan Medicine RuPeng15 powder in animal models of hyperuricemia

To evaluate the influence of the Tibetan medicine RuPeng15 powder (RPP15) on uric acid levels, and explore its possible mechanisms of action in hyperuricemic animal models. Hyperuricemic mice were generated by orally administering yeast extract paste twice daily (30 g/kg) for 8 days, to mimic human hyperuricemia induced by high-protein diets. Hyperuricemic rats were generated by intraperitoneal injection of 250 mg/kg potassium oxonate to each animal 1 h before the last oral administration of test compounds, which raised the serum uric acid level by inhibiting the decomposition of uric acid. Levels of uric acid and creatinine in serum and urine were detected by the phosphotungstic acid and picric acid methods respectively, and the activity of xanthine oxidase (XOD) was assayed using a commercial test kit. RPP15 (0.4, 0.8, 1.2 g/kg) significantly decreased the level of serum uric acid in healthy rats (P < 0.05). Furthermore, hyperuricemic rats treated with RPP15 (0.4, 0.8, 1.2 g/kg) had lower serum uric acid levels (P < 0.05), accompanied by lower urine uric acid (P < 0.05). For the hyperuricemic mice, the levels of uric acid in the serum decreased significantly (P < 0.05) and the activity of XOD in the liver was restored to normal levels after treatment with RPP15 (P <0.05). RPP15 (0.4, 0.8, 1.2 g/kg) demonstrated an anti-hyperuricemic effect on both healthy and hyperuricemic animals, and the mechanism is most likely associated with inhibiting the activity of XOD.