Chemoprotective effect of diallyl trisulfide from garlic against carbon tetrachloride-induced acute liver injury of rats.

Diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS) are principal constituents of garlic oil. We studied the effect of these sulfides on the phase II drug-metabolizing enzymes, and on the rat model of acute liver injury induced by carbon tetrachloride (CCl4). A highly purified form of each sulfide (more than 99% purity) was administered i.p. to rats at a concentration of 10 or 100 micromol/kg body weight for 14 consecutive days. DATS (10 micromol/kg) and DADS at a 10-fold higher dose (100 micromol/kg) significantly increased the activities of glutathione S-transferase (GST) and quinone reductase (QR); whereas DAS did not. In the CCl4-induced acute liver injury model of rats, DATS (10 micromol/kg) significantly suppressed the increase in plasma lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) activities. In conclusion, hepatic phase II enzymes were induced strongly by the trisulfide and weakly by the disulfide, but not by DAS. DATS significantly reduced the liver injury caused by CCl4. DATS may be one of the important factors in garlic oil that protects our body against the injury caused by radical molecules.