Glycine modulates hepatic lipid accumulation in alcohol-induced liver injury

We studied the effect of administering glycine, a non-essential amino acid, on serum and tissue lipids in experimental hepatotoxic Wistar rats. All the rats were fed standard pellet diet. Hepatotoxicity was induced by administering ethanol (7.9 g kg(-1)) for 30 days by intragastric intubation. Control rats were given isocaloric glucose solution. Glycine was subsequently administered at a dose of 0.6 g kg(-1) every day by intragastric intubation for the next 30 days. Average body weight gain at the end of the total experimental period of 60 days was significantly lower in rats supplemented with alcohol, but improved on glycine treatment. Feeding alcohol significantly elevated the levels of cholesterol, phospholipids, free fatty acids and triglycerides in the serum, liver and brain as compared with those of the control rats. Subsequent glycine supplementation to alcohol-fed rats significantly lowered the serum and tissue lipid levels to near those of the control rats. Microscopic examination of alcohol-treated rat liver showed inflammatory cell infiltrates and fatty changes, which were alleviated on treatment with glycine. Alcohol-treated rat brain demonstrated edema, which was significantly lowered on treatment with glycine. In conclusion, this study shows that oral administration of glycine to alcohol-supplemented rats markedly reduced the accumulation of cholesterol, phospholipids, free fatty acids and triglycerides in the circulation, liver and brain, which was associated with a reversal of steatosis in the liver and edema in the brain.