Walnut polyphenols prevent liver damage induced by carbon tetrachloride and d-galactosamine: hepatoprotective hydrolyzable tannins in the kernel pellicles of walnut.
The polyphenol-rich fraction (WP, 45% polyphenol) prepared from the kernel pellicles of walnuts was assessed for its hepatoprotective effect in mice. A single oral administration of WP (200 mg/kg) significantly suppressed serum glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) elevation in liver injury induced by carbon tetrachloride (CCl 4), while it did not suppress d-galactosamine (GalN)-induced liver injury. In order to identify the active principles in WP, we examined individual constituents for the protective effect on cell damage induced by CCl 4 and d-GalN in primary cultured rat hepatocytes. WP was effective against both CCl 4- and d-GalN-induced hepatocyte damages. Among the constituents, only ellagitannins with a galloylated glucopyranose core, such as tellimagrandins I, II, and rugosin C, suppressed CCl 4-induced hepatocyte damage significantly. Most of the ellagitannins including tellimagrandin I and 2,3- O-hexahydroxydiphenoylglucose exhibited remarkable inhibitory effect against d-GalN-induced damage. Telliamgrandin I especially completely suppressed both CCl 4- and d-GalN-induced cell damage, and thus is likely the principal constituent for the hepatoprotective effect of WP.
Shimoda
Hiroshi
H
Research & Development Division, Oryza Oil & Fat Chemical Co., Ltd., 1 Numata, Kitagata-cho, Ichinomiya, Aichi 493-8001, Japan.
Tanaka
Junji
J
Kikuchi
Mitsunori
M
Fukuda
Toshiyuji
T
Ito
Hideyuki
H
Hatano
Tsutomu
T
Yoshida
Takashi
T
D000818:Animals; D002251:Carbon Tetrachloride; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury; D005419:Flavonoids / Q000008:administration & dosage* / Q000302:isolation & purification; D005688:Galactosamine; D005707:Gallic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives; D005960:Glucosides / Q000008:administration & dosage; D006868:Hydrolysis; D031324:Juglans / Q000737:chemistry*; D008107:Liver Diseases / Q000517:prevention & control*; D010636:Phenols / Q000008:administration & dosage* / Q000302:isolation & purification; D059808:Polyphenols; D051381:Rats; D012639:Seeds / Q000737:chemistry*; D013634:Tannins / Q000008:administration & dosage* / Q000378:metabolism
D005419:Flavonoids; D005960:Glucosides; D010636:Phenols; D059808:Polyphenols; D013634:Tannins; D005707:Gallic Acid; D005688:Galactosamine; C087926:tellimagrandin I; D002251:Carbon Tetrachloride