Cytotoxic response of Aspergillus fumigatus-produced mycotoxins on growth medium, maize and commercial animal feed substrates

The occurrence of mycotoxin-producing moulds in animal feed is a severe problem since the quality of the feed is reduced and thereby both animal and human health can be affected. Aspergillus fumigatus is a common fungus found in improperly stored animal feed and the abundance of spores of the fungus is frequently spread into the air, exposing individuals who stay in areas where the fungus develops. The cytotoxic activities of extracts from three different A. fumigatus-inoculated substrates: (i) CzDox-broth; (ii) maize; and (iii) commercial feed grain as well as from gliotoxin, a mycotoxin produced by A. fumigatus, were studied in vitro using human neuroblastoma (SH-SY5Y) cells. Extracts of cultures from the gliotoxin-producing strain of A. fumigatus possessed cytotoxic activity in the cell system. Pure gliotoxin caused a 20% reduction of total protein content (EC20) at 0.12 +/- 0.02 muM, but also a 20% reduction in the number of neurites per cell body as compared with control cells (ND20) at 0.06 +/- 0.01 muM. The results show that use-of the SH-SY5Y cell model is a promising approach for detecting toxic activity in animal feed. Furthermore, the neurite degeneration of gliotoxin has to be investigated for estimation of a potentially neurotoxic risk. (C) 2002 Elsevier Science Ltd. All rights reserved.