Teas and other beverages suppress D-galactosamine-induced liver injury in rats.
We compared the effects of various types of beverages (teas, coffee, and cocoa) on D-galactosamine-induced liver injury by measuring plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in 7-wk-old male Wistar rats. The effects of five fractions extracted with different organic solvents from green tea, different types of dietary fibers, and some short chain fatty acids were also investigated. All of the beverages tested significantly suppressed D-galactosamine-induced enhancement of plasma enzyme activities when powdered beverages were added to the diet (30 g/kg) and fed to rats for 2 wk. Plasma ALT activities were 1155 +/- 82 [micromol/(min.L), control], 289 +/- 61 (green tea), 626 +/- 60 (roasted green tea), 471 +/- 84 (puerh tea), 676 +/- 69 (oolon tea), 423 +/- 76 (black tea), 829 +/- 53 (coffee), and 885 +/- 89 (cocoa). The profile of AST activities was similar. The caffeine-containing fraction from green tea had no significant effect, whereas the other four fractions, including the soluble fiber fraction, significantly suppressed liver injury. In addition to tea fibers, many other types of dietary fiber (hemicellulose, chitin, chitosan, alginate, pectin, guar gum, glucomannan, and inulin, but not cellulose) had liver injury-preventive effects when added to the diet (30 g/kg), suggesting that liver injury-prevention may be one of the general effects of dietary fibers. Of three short-chain fatty acids tested (acetate, propionate, and butyrate), only acetate prevented liver injury when added to the diet (15 g/kg), supporting the possibility that the liver injury-preventive effect of dietary fibers may be mediated at least in part by certain organic acids. These results suggest that several beverages possess preventive effects on certain types of liver injury, such as that induced by D-galactosamine, and that different constituents of high and low molecular weights contribute to the liver injury-preventive effects of green tea.
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan.
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Sugiyama
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He
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Wada
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Saeki
D000410:Alanine Transaminase / Q000097:blood*; D000704:Analysis of Variance; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood*; D001628:Beverages; D001786:Blood Glucose / Q000187:drug effects; D002099:Cacao; D002110:Caffeine / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D056486:Chemical and Drug Induced Liver Injury; D003069:Coffee; D004043:Dietary Fiber / Q000494:pharmacology*; D005688:Galactosamine / Q000037:antagonists & inhibitors*; D008107:Liver Diseases / Q000517:prevention & control*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013662:Tea; D015430:Weight Gain / Q000187:drug effects
D001786:Blood Glucose; D000697:Central Nervous System Stimulants; D003069:Coffee; D004043:Dietary Fiber; D013662:Tea; D002110:Caffeine; D005688:Galactosamine; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase