Lethality of Taurine and Alcohol Coadministration in Mice

Preventive or Curative Administration of Taurine Regulates Lipid Metabolism in the Liver of Rats with Alcoholic Liver Disease

Excessive consumption causes alcoholic liver disease (ALD), which injures hepatocytes and induces imbalance of lipid metabolism. Taurine is known to protect the liver from various liver injuries, and relieve lipid profile. Our previous studies also found that taurine can prevent or cure ALD, reduce fat deposition, but the mechanism remains unclear. In the present study, ALD rat model was established by administration of alcohol, pyrazole and high fat diet. Two percent taurine was administered at the same time or after ALD model establishment. Serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), serum and hepatic TC, TG, HDL-C and LDL-C were analyzed. Real-Time RT-PCR was conducted to detect the mRNA expressions of fatty acid synthetase (FAS), acetyl-CoA catboxylase (ACC), carnitine palmitoyl transferase 1 (CPT-1), 3-Hydroxy-3-methyl glutaric acid acyl Coenzyme A reductase (HMGCR), peroxisome proliferators activated receptor α (PPARα) and sterol regulatory element-binding protein 1c (SREBP-1c). The results showed that serum ALT, AST, serum and hepatic TC, TG and LDL-C were higher, while HDL-C in ALD model rats was lower than normal rats, the changes of which can be significantly relieved by taurine administration. mRNA expressions of ACC, FAS, CPT-1, HMGCR, PPARα and SREBP-1c which were significantly changed by ethanol can also be regulated by taurine. The results indicated that taurine can prevent and repair hepatic injury of ALD rats and balance lipid metabolism indexes in the liver, the mechanisms may involves in the regulation of related enzymes and transcriptional regulators participated in lipid metabolism.

Comparison of Toxicity of Taurine and GABA in Combination with Alcohol in 7-Day-Old Mice

Previously, we described the combined toxicity of taurine and alcohol, and assumed hypoglycemia to be one reason of this toxicity. To understand whether taurine-ethanol combined toxicity is exclusively connected to taurine or whether other inhibitory amino acids may have similar effects when combined with ethanol, we tested different doses of gamma-aminobutyric acid (GABA) in combination with ethanol in 7-day-old mice. The minimal dose of GABA in combination with 5 g/kg ethanol which could kill a mouse was 2 g/kg. GABA combined with ethanol at doses of 3 g/kg, 4 g/kg, 6 g/kg induced lethality of 30%, 90% and 100%, correspondingly. Taurine at the doses of 4 and 6 g/kg combined with ethanol induced death in 60 and 100% of mice. Ethanol (5 g/kg), taurine (6 g/kg), GABA (4 g/kg) administered alone and the combination of ethanol (5 g/kg) with taurine (3 g/kg) have no lethal effects. GABA (6 g/kg) applied alone induced 90% lethality. Taurine or GABA alone decreased blood glucose in a dose-depending manner. Ethanol potentiated GABA- and taurine-induced decrease in blood glucose and in some animals it dropped from 8.8 (intact) to a hypoglycemic level 3.1-3.3 mmol/L (GABA 4 g/kg, taurine 6 g/kg), but this may not be considered a single reason of death. We conclude that the combination of GABA and ethanol has a lethal effect and this is stronger than the combined toxicity of ethanol and taurine.

Taurine: the appeal of a safe amino acid for skeletal muscle disorders

Taurine is a natural amino acid present as free form in many mammalian tissues and in particular in skeletal muscle. Taurine exerts many physiological functions, including membrane stabilization, osmoregulation and cytoprotective effects, antioxidant and anti-inflammatory actions as well as modulation of intracellular calcium concentration and ion channel function. In addition taurine may control muscle metabolism and gene expression, through yet unclear mechanisms. This review summarizes the effects of taurine on specific muscle targets and pathways as well as its therapeutic potential to restore skeletal muscle function and performance in various pathological conditions. Evidences support the link between alteration of intracellular taurine level in skeletal muscle and different pathophysiological conditions, such as disuse-induced muscle atrophy, muscular dystrophy and/or senescence, reinforcing the interest towards its exogenous supplementation. In addition, taurine treatment can be beneficial to reduce sarcolemmal hyper-excitability in myotonia-related syndromes. Although further studies are necessary to fill the gaps between animals and humans, the benefit of the amino acid appears to be due to its multiple actions on cellular functions while toxicity seems relatively low. Human clinical trials using taurine in various pathologies such as diabetes, cardiovascular and neurological disorders have been performed and may represent a guide-line for designing specific studies in patients of neuromuscular diseases.