ABSTRACT
AIM To evaluate the prevention and treatment of N-(2-mercaptopropionyl)-glycine sodium (MPG-Na) and tiopronin (MPG) on acute liver injury. METHODS The experimental mouse model of hepatotoxicity induced by D-galactosamine (Gal) was applied to investigate preventive and remedial effects. In the preventive experiment, the mice were ip administered with MPG-Na or MPG 37.5，75 and 150 mg·kg~(-1), respectively, for 7 d. Gal 800 mg·kg~(-1) was ip given into the mice 30 min after the last administration. In the remedial experiment, the mice were ip given Gal 800 mg·kg~(-1) and 30 min later followed by MPG-Na or MPG 37.5, 75 and 150 mg·kg~(-1) , respectively, for 2 d. The mice were euthanized and serum was prepared 24 h (pre-treatment) or 48 h (post-treatment) after Gal injection. The activities of serum glutamyl pyruvic transaminase (GPT) and glutamyl oxaloacetic transaminase (GOT), the contents of total protein (TP) and albumin (Alb), and the Alb/globulin (A/G) ratio were determined. The liver tissues were collected for histopathological assessment (HE staining) under light microscope. RESULTS Compared with normal control group, the activities of serum GPT and GOT in model group were significantly increased. The injuries such as fatty degeneration and liver cell necrosis were observed. Compared with model group, the activities of GPT and GOT in pre-treatment groups were obviously decreased in MPG-Na 150 mg·kg~(-1) group. In post-treatment groups, the activity of GPT decreased in 3 MPG-Na groups. The contents of TP, Alb and A/G ratio had little change. In addition, MPG-Na alleviated the injuries such as fatty degeneration and liver cell necrosis obviously. Compared with MPG, MPG-Na showed similar effect. CONCLUSION MPG-Na has an obvious protective effect against Gal-induced acute liver injury in mice and the efficiency is equivalent as MPG.
ABSTRACT
Sulfur is an essential element for the entire biological kingdom because of its incorporation into amino acids, proteins and other biomolecules. Sulfur atoms are also important in the iron-containing flavoenzymes. Unlike humans, plants can use inorganic sulfur to synthesize sulfur-containing amino acids. Therefore, plants are an important source of sulfur for humans. Sulfur-containing compounds are found in all body cells and are indispensable for life. Some of sulfur-containing antioxidant compounds are, cysteine, methionine, taurine, glutathione, lipoic acid, mercaptopropionylglycine, N-acetylcysteine, and the three major organosulfur compounds of garlic oil, diallylsulfide, diallyldisulfide and diallyltrisulfide. In a comparison of the structure-function relationship among these sulfur-containing antioxidant compounds, dihydrolipoic acid (the reduced form of LA) is the most effective antioxidant. Dihydrolipoic acid contains two sulfhydryl groups and can undergo further oxidation reaction to form lipoic acid. The antioxidative activities of sulfur-containing compounds follow a general trend, the more highly reduced forms are stronger antioxidants and the number of sulfur atoms determine, at least in part, their modulatory activites on the glutathione related antioxidant enzymes. In this article, the antioxidant effects and the antioxidative activities, of sulfur-containing amino acids, are reviewed. In addition, the general antioxidant effects and the structure-function relationship of some sulfur-containing compounds are also reviewed.