당뇨병성 신병증에 대한 녹차 폴리페놀 성분의 예방적 효과

Abstract

Introduction: Diabetic nephropathy is a serious complication of diabetes mellitus and many studies have been conducted to prevent progression of nephropathy. Recently, there has been a search for natural products for the prevention and treatment of diabetic nephropathy. Polyphenol has two or more phenolic ring structures and is known to have physiological activities such as antioxidative action, antibacterial action and anticancer action. Catechin is a type of polyphenols and has been known to lower blood sugar levels in diabetes. The purpose of this study was to investigate the effect of catechin on the protection of diabetic nephropathy.

Methods: Diabetes mellitus was induced in SD rats by high fat diet and low dose streptozotocin injection. The experimental group was divided into three groups: control group, diabetes mellitus(DM) group and diabetes mellitus + catechin(DM+CA) group. In the control group and the DM group, tap water was supplied as drinking water, and 0.2% catechin tap water was supplied to the DM+CA group for 16 weeks with drinking water. Blood glucose, blood urea nitrogen and creatinine levels were measured in the blood, alkaline phosphatase and gamma glutamyl transpeptidase activity and renal transcriptome were analyzed in renal tissue.

Results: Blood creatinine and BUN in DM group were higher than control group, and blood creatinine and BUN in DM+CA group were lower than DM group. The transcriptomes of the kidneys showed 5 genes related to gas transport, 10 genes related to response to extracellular stimulus, 13 genes related to response to organic substance, 4 genes related to response to starvation, 6, genes related to water transport, 3 genes for response to vitamins, and 9 genes for response to hormone stimulus were changes in the DM group compared to the control group. These changes in gene expression may be related to the development of diabetic nephropathy. Compared to the DM group and DM + CA kidney transcripts, the genes with different RNA expression levels were nine genes related to oxidation reduction, seven genes related to response to endogenous stimulation, six genes related to response to wounding, 8 genes involved in the response to organic substance, 4 genes involved in the inflammation response, 5 genes involved in defense reactions, and 2 genes related to glycine metabolism. These results suggest that administration of catechine to diabetic rats reduces BUN and creatinine levels and in kidney AP and GGT activity. In addition, transcriptomes analysis showed that changes in the gene expression of diabetic rat kidney were associated with the development of diabetic nephropathy. Genes with different gene expression levels in diabetes + catechin and diabetic groups were thought to have undergone changes in renal tissue gene expression by the action of catechin, and reduced renal damage in diabetic rats treated with catechin may be associated with changes in gene expression.

Conclusion: Catechin seems to be effective in the prevention of diabetic nephropathy, and changes in transcripts of diabetic kidney by catechin administration may be related to the prevention of diabetic nephropathy. There is a continuing need for further study of whether diabetic nephropathy is induced or prevented by altered expression of a gene