Nodular hyperplasia in the rat liver following prolonged feeding of ponceau MX

Abstract

Dietary levels of 0·0 (control), 0·125, 0·25, 0·5 and 1·0% Ponceau MX were fed to groups of rats for 2 yr. At all levels of treatment the death rate increased and the rate of body-weight gain was reduced. The reduced weight gain was associated with a reduced food intake, but the diet was shown to be unpalatable only at the 1 % level. Urinary excretion of ascorbic acid was increased after the feeding of dietary levels of 0·25 % or above for 1 yr. Anaemia occurred in rats fed on the two highest levels of the colouring (0·5 and 1·0%).Histopathological changes attributable to treatment with Ponceau MX were found only in the liver, but occurred at all levels of treatment. The lesions consisted of necrosis, small areas of enlarged hepatocytes and nodules consisting either of areas of regeneration and fibrosis or of multilocular cysts. These changes are consistent with nodular hyperplasia following hepatocellular necrosis.These studies show that Ponceau MX is hepatotoxic at the dietary levels administered but provide no evidence to suggest that it has any carcinogenic potential.