Protective Effects Of Catechin On Gene Expression Of Glucose Metabolism In Streptozotocin-Induced Daibetic Nephropathy In Rats

Abstract Background and Aims Diabetes patients continue to increase worldwide, and persistent hyperglycemia could induce diverse complications, such as diabetic nephropathy. The purpose of this study was to investigate the transcriptoms of liver, muscle and adipose tissue to observe the effects of catechin on glucose metabolism in diabetic nephropathy rats. Method The experimental group was divided into control group, diabetic nephropathy (DN) group and DN + catechin group. The control and diabetic groups received tap water as drinking water and the DN + catechin group received tap water containing 0.1% catechin as drinking water for 12 weeks. After 12 weeks, blood glucose, BUN and creatinine levels were measured in the blood and transcriptomes were examined in liver, soleus muscle and visceral fat. The gene expression levels of glucose metabolism-related enzymes, lipid metabolism-related enzymes and insulin signaling pathway-related proteins were compared between each experimental group. Results Fasting blood glucose in the diabetic + catechin group was decreased by 8%, 13%, 15% and 18% at 2, 4, 8 and 12 weeks, respectively, compared to the diabetic group. After 12 weeks, serum BUN levels in the DN + catechin group decreased by 35% and serum creatinine levels by 33%, respectively, compared to the DN group. Glucose metabolism-related genes in the DN group were decreased in liver Gck, Pdp2 and Phkb mRNA levels, and Aldob mRNA levels in soleus muscle were decreased. In DN group, expression of Pfkm, Eno3 and Pgam2 in visceral fat were increased and Aldob and Pklr expression was decreased. Hepatic Gck, Pdk4 and Phkb mRNA levels were increased in the DN + catechin group compared to the DN group. Conclusion Catechin has the effect of improving diabetic nephropathy, which is thought to be the result of increased expression of liver glucose metabolism related enzymes and proteins related to insulin signal transduction pathways. Further study is needed to elucidate the mechanism of action on catechin gene expression and its usefulness as a functional substance.