Polyphenols from Camellia sinenesis prevent primary graft failure after transplantation of ethanol-induced fatty livers from rats

Abstract

Fatty liver caused by ethanol decreases survival after liver transplantation in rats. This study investigated if antioxidant polyphenols from Camellia sinenesis (green tea) prevent failure of fatty grafts from ethanol-treated rats. Donor rats were given ethanol intragastrically (6 g/kg). After 20 h, livers were explanted and stored in University of Wisconsin solution for 24 h. Prior to implantation, the explanted grafts were rinsed with lactated Ringer's solution containing 0 to 60 μg/ml polyphenols. Alanine aminotransferase (ALT) release after liver transplantation was 4.5-fold higher in recipients receiving ethanol-induced fatty grafts than in those receiving normal grafts. Liver grafts from ethanol-treated donors also developed severe focal necrosis. Graft survival was 11% in the ethanol group versus 88% for normal grafts. Polyphenol treatment at 60 μg/ml blunted ALT release by 66%, decreased necrotic areas by 84%, and increased survival to 75%. Ethanol increased α-(4-pyridyl-1-oxide)- N- tert.-butylnitrone free radical adducts in bile by 2.5-fold, as measured by electron spin resonance spectroscopy, and caused accumulation of 4-hydroxynonenal in liver sections, effects blunted by polyphenols. Epicatechin gallate, a major polyphenol from C. sinenesis, also decreased enzyme release, minimized pathological changes, and decreased free radical adduct formation. In conclusion, polyphenols scavenged free radicals in ethanol-induced fatty livers and decreased injury after liver transplantation.