PREVENTION BY ESTRADIOL OF AFLATOXIN-INDUCED CYTOTOXICITY IN CULTURED CHICK EMBRYO LIVER CELLS

Abstract

Aflatoxin B₁ at a final concentration of 10^-5 M depressed the sytheses of DNA, RNA and protein in cultured chick embryo liver cells. The same dose produced ultrastructural changes in the nucleus, such as nucleolar compactness or segregation of fibrillar and granular components and in the cytoplasmic area, such as vesiculation, dilatation or degranulation of endoplasmic meticulum. These acute toxic effects of aflatoxin B₁ were partially decreased by an addition of 4 × 10^-5 M estradiol-17β. Namely estradiol-17β significantly reduced the nucleolar compactness and segregation of fibrillo-granular components but did not improve the vesiculation, dilatation and degranulation of endoplasmic reticulum. Estradiol-17β also protected the liver cells from the aflatoxin B₁-induced inhibition of nucleic acid and protein synthesis. These results suggest that the protective effect of estradiol-17β against the acute hepatotoxicity of aflatoxin B₁ is mainly due to an antagonistic interaction of both compounds on the synthesis of nucleic acid in nucleolus.