Hepatoprotection by dimethyl sulfoxide. I. Protection when given twenty-four hours after chloroform or bromobenzene

Dimethyl sulfoxide (DMSO) has previously been reported to protect against hepatotoxicity resulting from chloroform (CHCl3) or bromobenzene (BB) when given 10 hr after the toxicant. The object of these studies was to further demonstrate the latent protective ability of DMSO by administering it at a much later time (24 hr) following toxicant exposure. In addition, a more detailed evaluation of the lesions was performed to better characterize the lesion progression and resolution. Male Sprague-Dawley rats received a hepatotoxic oral dose of either CHCl3 (1.0 ml/kg) or BB (0.5 ml/kg) and then received 2 ml/kg DMSO intraperitoneally 24 hr later. With both toxicants, limited centrilobular lesions were already present by the time DMSO was administered. Without treatment, liver injury rapidly progressed so that by 48 hr it occupied 40-50% of the liver, with accompanying large increases in plasma alanine aminotransferase (ALT) activity. Administration of DMSO greatly attenuated lesion development for both toxicants; the area injured was reduced by more than 4-fold, accompanied by a decrease in 48 hr ALT activity of 8-16-fold. The ability of DMSO to intervene in the development of liver injury at such a late time appears to be unique and may provide insight into therapies for acute xenobiotic-induced hepatitis.