Total saponins from Discorea nipponica makino ameliorate urate excretion in hyperuricemic rats

OBJECTIVE: The objective was to study the mechanism of reducing level of the uric acid by rhizoma dioscoreae nipponese. MATERIALS AND METHODS: A total of 40 rats were divided into four groups: A normal group, hyperuricemia group, benzbromarone group (9 mg/kg) and total saponins from rhizoma dioscoreae nipponese (TDN) group (40 mg/kg). Adenine (100 mg/kg) and ethambutol (250 mg/kg) were used to induce hyperuricemic rats. Immunohistochemical and Western blotting methods were used to detect the mRNA and proteins expressions of rat organic anion transporter1 (rOAT1), rat organic anion transporter3 (rOAT3) and rat urate transporter1 (rURAT1) in the kidneys of different groups. RESULTS: It was found that the reduced concentration of blood uric acid was due to the enhancement of renal uric acid excretion. It was realized by up-regulating proteins expressions of rOAT1 and rOAT3 and down-regulating of rURAT1. CONCLUSION: The findings suggested that there were uricosuric effects of TDN by regulating renal organic ion transporters in hyperuricemic animals. Altogether, TDN may be a good Chinese herb in treating hyperuricemia, even a potential drug for gouty arthritis.