The Researches Of Catechins On Reducing The Level Of Uric Acid

China is the earliest country to discover and utilize the resources of tea plants. We can extract oil from tea seed and product tea,drink tea from fresh tea leaves. Whereas, a great deal of by-products such as old tea leaves and camellia are in a waste stage. There are so much active substance—tea polyphenols in these by-products. A wide array of studies confirm that tea polyphenols have so many health functions, the typical examples include antioxidant, antisenescent, antibacterial, anticancer and prevention heart and brain blood vessel disease. With the improvement of living standards and the changes in diet, hyperuricemia which is metabolic disease has become threatening people’s life health. And hyperuricemia is closely related to hypertension, hyperlipidemia, atherosclerosis, obesity, insulin resistance. Some studies find that tea polyphenols could reduce serum uric acid levels in the hyperuricemic mice. However, studies about the effect of catechins to decrease uric acid have not been reported. This study focus on the effect of decreasing uric acid about the catechins in acute hyperuricemia mice, rats and chronic hyperuricemia rats and to explore the possible mechanism.The main researches and results in this study are listed below:Establishing the evaluation system about the decreasing the uric acid can evaluate the effect comprehensively. The evaluation system conclude that establishing the stable and repeatable model of acute hyperuricemia mice and rats, chronic hyperuricemia rats. The acute hyperuricemia mice model is established by intraperitoneal injection of 300mg/Kg oxonic acid potassium. The mice blood sampling time point is 1.25 hours after intraperitoneal injection. The acute hyperuricemia rats model is established by intraperitoneal injection of 250mg/Kg oxonic acid potassium. The rats blood sampling time point is 2.25 hours after intraperitoneal injection. The chronic hyperuricemia rats model is established by irrigation 4g/Kg oxonic acid potassium and 0.1g/Kg hypoxanthine for 18 days.To study the effect of catechins on acute hyperuricemia mice, the results in acute hyperuricemia mice model by intraperitoneal injection oxonic acid potassium show that group of TP, EC, ECG and EGC could decrease the serum uric acid level significantly by 19.33%, 23.31%,35.11% and 37.13% without any impacting to the weight, liver and kidney function of mice. However, the EGCG which is the highest content of tea polyphenols has no effect on decreasing the uric acid. Further study showed that ECG and EGCG inhibit the activity of xanthine oxidase(XOD)in vitro. And ECG inhibits the activity of serum and liver XOD in mice. Indicate that the effect of lowering uric acid of ECG may be related to the inhibition of XOD activity.To study the effect of catechins on acute hyperuricemia rats, the results in acute hyperuricemia rats model by intraperitoneal injection oxonic acid potassium show that group of EC and EGC could decrease the serum uric acid level significantly by 49.88% and 51.77% without any impacting to the weight, liver and kidney function of mice. But ECG which has the effect of decreasing the uric acid in acute hyperuricemia mice has no effect in acute hyperuricemia rats model. The result may be caused by species differences.To study the effect of catechins on chronic hyperuricemia rats, the results in chronic hyperuricemia rats model by intragastric administration oxonic acid potassium and show that group of EC and EGC could decrease the serum uric acid level significantly by 45.03% and 68.38% without any impacting to the weight, liver and kidney function of rats. ECG still has no effect on decreasing the uric acid in the chronic hyperuricemia rats. In summary, EC and EGC of tea polyphenols could significantly decrease the uric acid in hyperuricemia mice and rats. ECG could significantly decrease the uric acid only in hyperuricemia mice. EGCG which is the highest content in tea polyphenols has no effect on decreasing the uric acid in hyperuricemia mice and rats.In summary, the catechins of tea polyphenols which could decrease the serum uric acid in hyperuricemic mice and rats are EC and EGC; ECG only decrease the serum uric acid significantly in hyperuricemic mice; EGCG which is the highest content in tea polyphenols has no effect on decreasing the uric acid in hyperuric mice and rats. This study provide a scientific basis for the comprehensive utilization of tea plants and catechins.