Study On The Effect And Mechanism Of Black Tea And Tea Peptides In Relieving Metabolic Syndrome

Excess energy intake and reduced energy expenditure result in abnormal excessive growth of adipose tissue,which can lead to the development of obesity.Obesity is strongly associated with metabolic syndrome,which is characterized by the presence of insulin resistance,hypertension,and hyperlipidemia.Metabolic syndrome,which is closely linked with atherosclerosis,is widely recognized as a major public health problem.We obtained black tea infusion from it,and the effectiveness of oral administration of the black tea extracts(BTE)was examined in experiments.Methods: effects of BTE on pancreatic lipase activity were investigated,and sequential plasma lipid levels were measured.ICR mice were fed a standard supplemented with BTE at a concentration of 500,1000 or 2000 mg/kg body weight for 2wk and changes in body weight were examined.Immunoblotting and HE staining was determined.Conclusion: The BTE reduced feed intake of mice and may prevent obesity by inhibiting lipid absorption.It was suggested that BTE mays regulated adipogenic process through the LKB1/AMPK pathway.Type 2 diabetes(T2D)is a chronic metabolic disorder affecting a significant number of global populations and the prevalence is rising uncontrolled.In addition,as many as onethird of individuals with T2 D are undiagnosed and in particular is recognized as a global public health concern.Poorly controlled diabetes is associated with some complications including nephropathy,atherosclerosis,retinopathy,and neuropathy.Amongst all diabetesassociated complications,diabetic nephropathy(DN)has probably the most detrimental consequences resulting in dialysis and heightened cardiovascular risks.Approximately 30% of diabetic patients suffer from diabetic nephropathy,eventually undergoing renal dialysis or transplantation.The conspicuous pathologic changes of diabetic nephropathy are persistent albuminuria,altered creatinine clearance,mesangial matrix expansion,glomerular basement membrane(GBM)thickening,and glomerular sclerosis.In this study,therapeutic potential and the underlying molecular mechanisms of tea polypeptides(TP),natural bioactive peptides isolated from green tea,against diabetic nephropathy were investigated.TP treatment for five weeks significantly reinstated the blood glucose,HOMA-IR,HOMA-IS and lipid levels in serum,and also restored the renal physiology in T2 D mice.Molecular mechanism studies demonstrated that TP treatment stimulated polyol pathway,PKC?/JNK/NF-?B/TNF-?/iNOS and AGEs/RAGE/TGF-?1,upregulated the expressions of podocin in glomerulus and reduced the secretion of pro-inflammatory cytokines in T2 D mice.These results suggest a possibility of TP to be a new therapeutic agent for DN in future.