Toxicity and Mutagenicity of Patulin in Different Test Systems

Abstract

Patulin, a mycotoxin produced by some Aspergillus, Penicillium, and Byssochlamys species, is found in rotten fruits and fruit products. By its structure, an unsaturated α,β-lactone, it reacts with sulfhydryl groups. Patulin inhibits the growth rate of the ciliate Tetrahymena at a concentration of 3.2 μg/ml by 50%. Using the same patulin concentration, the protein synthesis of this organism is inhibited by 85% and the RNA synthesis by 86% compared with the control. Four hours after addition of the mycotoxin (3.2 μg/ml), DNA synthesis is reduced to 20%; it rises to the value of the control after an additional 2 h. An in vitro system could be developed consisting of permeabilized cells of Tetrahymena. This system allows the separation of regulatory and secondary effects induced by patulin. The mycotoxin reduces DNA synthesis by 50%, whereas RNA and protein synthesis are less inhibited than in the in vivo system. A further characterization of these results could be obtained by experiments with the large fragment of DNA polymerase I. Patulin inhibits the enzyme at rather high concentrations.

This paper is presented in tribute to the memory of Prof. R. J. Röschenthaler