Exploration of the role of bound polyphenols on tea residues dietary fiber improving diabetic hepatorenal injury and metabolic disorders

Consumption of tea residues dietary fiber (TRDF) contributed to the relief of hyperglycemia symptoms in type 2 diabetes (T2D). Given the properties of TRDF abundant in bound polyphenols, the research intended to evaluate the effect of the presence or absence of bound polyphenols in TRDF on the improvement of diabetic complica-tions (liver and kidney injury, metabolic disorders) in T2D rats induced by high-fat diet and streptozocin in-jection. Our results revealed that the presence of bound polyphenols in TRDF was remarkably beneficial for the amelioration of liver and kidney damage caused by T2D, which was supported by significant differences in activities of serum glutamic oxaloacetic transaminase (AST) and glutamic-pyruvic transaminase (ALT), contents of inflammatory factors in liver and kidney, the levels of kidney oxidative stress, as well as histopathological status between TRDF and bound polyphenols removed-TRDF (TRDF-DF) groups. In addition, metabolomic analysis revealed that TRDF interventions could increase the levels of metabolites such as S-Adenosylmethionine, L-Homophenylalanine and Riboflavin, as well as differ in the regulation of the metabolic pathways including arachidonic acid metabolism and cysteine and methionine metabolism as compared to TRDF-DF without bound polyphenols. These results suggested that bound polyphenols ensured the health-promoting effects for T2D complications of TRDF.