Therapeutic potential of (-)-epigallocatechin 3-O-gallate on renal damage in diabetic nephropathy model rats.
Previous investigations have demonstrated that green tea polyphenols and partially hydrolyzed guar gum as dietary fiber have antioxidative and hypolipidemic activity, respectively, supporting their reduction of risk factors in the course of diabetic nephropathy via a hypoglycemic effect and ameliorating the decline of renal function through their combined administration to rats with subtotal nephrectomy plus streptozotocin (STZ) injection. As a further study, we examined whether (-)-epigallocatechin 3-O-gallate (EGCg), the main polyphenolic compound, could ameliorate the development of diabetic nephropathy. Rats with subtotal nephrectomy plus STZ injection were orally administrated EGCg at doses of 25, 50, and 100 mg/kg body weight/day. After a 50-day administration period, EGCg-treated groups showed suppressed hyperglycemia, proteinuria, and lipid peroxidation, although there were only weak effects on the levels of serum creatinine and glycosylated protein. Furthermore, EGCg reduced renal advanced glycation end-product accumulation and its related protein expression in the kidney cortex as well as associated pathological conditions. These results suggest that EGCg ameliorates glucose toxicity and renal injury, thus alleviating renal damage caused by abnormal glucose metabolism-associated oxidative stress involved in renal lesions of diabetic nephropathy.
Yamabe
Noriko
N
Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
Yokozawa
Takako
T
Oya
Takeshi
T
Kim
Mujo
M
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D051546:Cyclooxygenase 2 / Q000032:analysis; D003928:Diabetic Nephropathies / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D005353:Fibronectins / Q000032:analysis; D007668:Kidney / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D016328:NF-kappa B / Q000032:analysis; D052247:Nitric Oxide Synthase Type II / Q000032:analysis; D009929:Organ Size / Q000187:drug effects; D011507:Proteinuria / Q000188:drug therapy; D051381:Rats; D017208:Rats, Wistar; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000032:analysis
D005353:Fibronectins; D016328:NF-kappa B; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D016212:Transforming Growth Factor beta; D002392:Catechin; C045651:epigallocatechin gallate; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2