ABSTRACT
Hyperuricemia is not only the biochemical basis of gout, but also closely related to the development of metabolic syndrome, cardiovascular diseases, chronic kidney disease, etc. Xanthine oxidase (XOD) is the key catalytic enzyme for uric acid biosynthesis, therefore the vital target for anti-hyperuricemic drugs. In this study, compound CC18022 was designed and synthesized specifically targeting to XOD. Molecular docking analysis indicated a fairly tight binding between CC18022 and XOD. In the in vitro study, CC18022 significantly inhibited XOD activity with a half maximal inhibitory concentration (IC50) value in the order of nmol·L-1, which is relative to the XOD inhibitor febuxostat. By using both acute and chronic hyperuricemic mice model, compound CC18022 was found to have serum uric acid-lowering effect in a dose-dependent manner in vivo. The animal welfare and experimental processes were in accordance with the provisions of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences. In the acute hyperuricemic mice, CC18022 significantly inhibited serum XOD activity, and also the XOD activity in intestine and liver, which were related to purine absorption and metabolism. Therefore, the novel compound CC18022 exhibited significant inhibition on XOD activity and anti-hyperuricemic effects, making it a favorable candidate for further research.
ABSTRACT
Aim To establish a screening system for xanthine oxidase (XOD) inhibitors. Methods The XOD activity in vitro, serum uric acid level, serum XOD activity, tissue XOD activity and the blood indexes related to liver and kidney function were determined by biochemical method, respectively. Pathological analysis was used to observe liver and kidney. Results The optimized reaction consists of 3 U . L 1 XOD and 50 u,mol . L 1 XA under pH7.4, 37 °C. for 20 min. The high throughput screening method was established for XOD inhibitors in vitro. The acute hyperuricemia models were induced by signle dose of hypoxanthine and oteracil potassium in ICR mice. In this case, the serum uric acid level had a transient elevation after inducer administered. The changes of serum uric acid levels and the area under the uric acid-time curve were used to evaluate the acute hyperuricemia mice. The chronic hyperuricemia models were selected from the ICR mice stimulated with oteracil potassium consecutively. No significant changes of XOD activities in serum and tissue, of function and pathological structure in liver and kidney were observed in both acute hyperuricemia mice and chronic hyperuricemia mice. Conclusions The high throughput screening method for XOD inhibitors in vitro and the evaluation in vivo, in acute or chronic hyperuricemia mice, respectively, are mutually verified, forming an experimental system for developing the anti-hyperuricemia drug targeting at XOD.