Effects of Holothurin A and Echinoside A from Sea Cucumber on Uric Acid Metabolism in Obese Mice

Holothurin A (HA) and Echinoside A (EA) are two major saponins in sea cucumbers. In the present study, the effects of HA and EA on uric acid metabolism were evaluated by determining the level of serum uric acid, the activity of uric acid metabolism-related enzymes and the mRNA expression of renal transporters in db/db mice. The db/db mice were divided into 3 groups (n=8), including model, HA and EA groups, according to the body weight. C57/BL6 mice was used as the control group. The mice in HA and EA groups were supplemented with 0.07% HA and EA for 2 weeks, respectively. Results showed that the mice in the model group showed a significant increase in serum uric acid levels compared with the control group. Dietary intervention with HA and EA significantly reduced the serum uric acid level by 12.7% and 18.1%, respectively(P<0.05), and significantly alleviated the pathological changes of renal tissue represented by glomeruli. Mechanism studies showed that no significant difference was observed in the activities of liver xanthine oxidase and adenosine deaminase among the four groups(P>0.05). The mRNA expression of transporters, including GLUT9, OAT1, OCTs and OCTNs, were significantly elevated after administration with HA and EA(P<0.05). HA and EA may alleviate hyperuricemia by regulating the mRNA expression of renal uric acid metabolism-related transporters, in which EA is better than the HA. The obtained results may provide theoretical basis for dietary sea cucumber saponins to prevent abnormal uric acid metabolism.