海参皂苷Holothurin A和Echinoside A对肥胖小鼠尿酸代谢的影响

Holothurin A (HA)和Echinoside A (EA)是海参中含量较高的两种皂苷，本研究分析了HA和EA对db/db肥胖小鼠血尿酸、尿酸代谢相关酶活性及肾脏尿酸代谢相关转运体mRNA表达的影响。将db/db小鼠按体重分成模型组、HA组、EA组，每组8只，C57/BL6小鼠为对照组，HA组、EA组饲料分别添加0.07%两种海参皂苷单体，喂养2周。结果显示，相比对照组小鼠，模型组小鼠表现为血清尿酸水平显著升高，海参皂苷HA与EA分别降低血尿酸12.7%和18.1%（P<0.05），并显著改善肾脏肾小球组织结构病理学变化。实验结果表明，海参皂苷对db/db肥胖小鼠肝脏黄嘌呤氧化酶和腺苷脱氨酶的活性无显著影响(P>0.05)，但显著上调肾脏尿酸代谢相关转运体GLUT9、OAT1、OCTs、OCTNs 的mRNA表达水平（P<0.05）。海参皂苷HA和EA可能通过调控肾脏尿酸代谢相关转运体改善尿酸代谢异常，其中EA改善效果优于HA。该研究成果为膳食海参皂苷预防尿酸代谢异常提供理论依据。

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.