Prevention of carbon tetrachloride-induced liver necrosis by the chelator alizarin sodium sulfonate

N-acetyl cysteine is an early but also a late preventive agent against carbon tetrachloride-induced liver necrosis

N-Acetyl cysteine (NAC) treatment 30 min before or 6 or 10 h after carbon tetrachloride (CCl4) administration significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. NAC pretreatment was able to partially decrease the covalent binding of CCl4 reactive metabolites at 1 and 3 h of poisoning and, to a small extent, the concentration of CCl4 reaching the liver at 3 h. NAC also diminished partially the CCl4-promoted increases in lipid peroxidation at 3 h, but had an enhancing effect of its own of small intensity. Results suggest that early and late protective effects of NAC might be attributable to its prior conversion to cysteine and glutathione.

Antioxidative stress therapy with dithiothreitol tetraacetate. I. Protection against carbon tetrachloride induced liver necrosis

Dithiothreitol (DTT) is known to prevent or even reverse several deleterious effects of radiation or of chemical agents operating via free radical and oxidative stress. However, its use has been hampered by its chemical instability and toxic properties. In this work, we synthesized and characterized dithiothreitol tetraacetate (DTT-Ac) which is less toxic and chemically stable, and we provided GLC/MS evidence that it is able to rapidly generate fully deacetylated DTT in liver after its administration to rats. Treatment with DTT-Ac simultaneously with CCl4 or 3 h after the hepatotoxin was able to significantly prevent the CCl4-induced liver necrosis at 24 h after poisoning. DTT-Ac administration was able to significantly reduce the intensity of the covalent binding of CCl4 reactive metabolites to microsomal lipids (CB), but it did not prevent the CCl4-induced initiation of a lipid peroxidation (LP) process as evidenced by diene hyperconjugation of microsomal lipids. Results suggest that DTT-Ac protective effects might be due to its in vivo conversion to DTT which in turn would decrease the intensity of CB via different potential mechanisms to be explored. Protection cannot be attributed to decreases in levels of CCl4 reaching the liver or to chain breaking effects on LP.