title: Green Tea Polyphenol Prevents Diabetic Rats From Acute Kidney Injury After Cardiopulmonary Bypass.
abstract: BACKGROUND
  Acute kidney injury (AKI) is a common complication accompanying cardiopulmonary bypass (CPB) and is independently associated with increased morbidity and death. Diabetes mellitus increases the risk for AKI after CPB. Epigallocatechin-3-gallate (EGCG) is a major component of the polyphenolic fraction of green tea, which possesses cardioprotective activities, as previously reported. We hypothesized that EGCG also possesses a renoprotective effect through its diverse biochemical properties and assessed the effect on renal function after CPB for diabetic rats.
  
  
  METHODS
  Goto-Kakizaki rats developing type 2 diabetes mellitus were randomly assigned to one of the following groups: sham (n = 10), CPB (CPB alone, n = 9), or EGCG (CPB + EGCG, n = 10). CPB was conducted for 30 minutes at a flow rate of 100 mL/kg/min in the CPB and EGCG groups. Rats assigned to the EGCG group were administrated EGCG solution orally for 2 weeks before CPB. We evaluated renal biochemical or histologic changes at 24 hours after CPB.
  
  
  RESULTS
  Compared with the CPB group, the EGCG group exhibited milder tubular injury histologically (p < 0.0001) and reduced expression of kidney injury molecule-1, a biomarker for renal tubular injury (p < 0.0001) and 8-hydroxy-2'-deoxyguanosine (p < 0.01), indicating attenuated oxidant stress.
  
  
  CONCLUSIONS
  Preoperative oral administration of EGCG ameliorates AKI in a CPB model of diabetic rats through antioxidative properties. This simple method could be applied in a clinical setting as a prophylactic renal protection against AKI after CPB, especially for high-risk patients with diabetes mellitus.
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Funamoto
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Masumoto
authors.affiliation: Department of Nephrology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Takaori
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Taki
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Setozaki
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamazaki
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Minakata
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan. Electronic address: ike@kuhp.kyoto-u.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Center for Fiber and Textile Science, Kyoto Institute of Technology, Kyoto, Japan.
authors.forename: Suong-Hyu
authors.initials: SH
authors.lastname: Hyon
authors.affiliation: Department of Cardiovascular Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Sakata
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D000284:Administration, Oral; D000818:Animals; D001707:Biopsy, Needle; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000379:methods; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives; D003921:Diabetes Mellitus, Experimental; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D007150:Immunohistochemistry; D007677:Kidney Function Tests; D008297:Male; D059808:Polyphenols / Q000008:administration & dosage*; D011300:Preoperative Care / Q000379:methods; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012016:Reference Values; D018570:Risk Assessment; D013662:Tea; D016896:Treatment Outcome
chemical_list: D059808:Polyphenols; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate