Cytotoxic and mutagenic effects of sterigmatocystin on cultured Chinese hamster cells.

Cytotoxic and mutagenic effect of sterigmatocystin (STC), a carcinogenic mycotoxin, on cultured Chinese hamster cells were investigated in the presence or absence of a metabolic activation system. STC directly applied to the cells induced cytotoxicity and drug-resistant mutations in a time- and concentration-dependent manner. Analyses of the effects of STC showed that treatment for shorter periods was more effective than that for longer periods. The presence of an activation system, cytotoxic and mutagenic effects of STC were strongly enhanced, and 1% of the microsome fraction was most efficient in inducing the effects. Analyses by equitoxic comparison showed that there was little difference in mutagenic activity between the direct treatment and the treatment using an activation system.