Dietary copper enhances the hepatotoxicity of senecio jacobaea in rats

Abstract

To determine the effects of dietary copper on the toxicity of Senecio jacobaea (tansy ragwort), a plant that contains the hepatotoxic pyrrolizidine alkaloids (PAs), young male rats were fed diets containing 0 or 5% dried tansy ragwort tops and 0 or 5% μg/g copper (as copper sulfate) for 5 weeks. Hepatotoxicity was measured by the activities of plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Comsumption of diets containing 5% tansy ragwort alone produced a significant reduction in weight gain accompanied by a 122% increase in plasma AST activity, a 106% increase in ALP activity, and a 152% increase in ALT activity, compared to pair-fed controls. When copper was added to the tansy ragwort diet, the activities of both plasma AST and ALT were increased by more than 350%. Plasma ALP activity was also further enhanced by dietary copper in the tansy ragwort-fed animals but to a lower extent. Supplementary copper alone or a reduction in food intake had no significant effect on any of the enzyme activities. The results suggest that copper potentiates the hepatotoxic effects of tansy ragwort in rats.