Effect of gavage vehicle on hepatotoxicity of carbon tetrachloride in CD-1 mice: Corn oil versus tween-60 aqueous emulsion

Abstract

This investigation was conducted to evaluate the effect of gavage vehicles on altering the severity of the subchronic hepatotoxicity of carbon tetrachloride (CCl 4). Male and female CD-1 mice were gavaged with 0, 1.2, 12, and 120 mg/kg CCl 4 in either a corn oil or 1% Tween-60 vehicle once daily for 5 consecutive days per week for 90 days. The study revealed that the hepatotoxicity was greater in the mid- and high-dose groups of mice that had received CCl 4 administered in corn oil. Increases in serum enzyme activities were detected in the mid-dose groups of mice that were gavaged with CCl 4 in corn oil. The serum enzyme activities were significantly higher in the high-dose groups of animals in which CCl 4 was administered in corn oil. Histopathological findings indicated that hepatocellular changes following the administration of CCl 4 at the mid- and high-dose levels were more frequent and more severe when CCl 4 was given in corn oil than when it was administered in Tween-60. The experimental findings indicate that the no-observed-adverse-effect level from CCl 4 exposure was lowered by an order of magnitude (from 12 to 1.2 mg/kg) and that the hepatotoxicity of CCl 4 was enhanced in the high-dose treatment groups when corn oil was employed as the gavage vehicle.