Cytotoxicity of aflatoxin B-1 and its chemically synthesised epoxide derivative on the A549 human epithelioid lung cell line

Aflatoxin B-1 (AFB(1)) is a carcinogenic mycotoxin found in feeds and in ai rborne grain dusts. Aflatoxin B-1 requires biotransformation to the AFB(1)- 8,9 epoxide (AFBO) by a bioactivation system and subsequent covalent bindin g to DNA or proteins, to exert its carcinogenic potential. The lung contain s cytochrome P-450, prostaglandin-H-synthase, lipoxygenase, epoxide hydrola se and other bioactivation enzymes, and is thus a potential target for the effects of AFB(1) via the routes of inhalation and ingestion. The A549 huma n epithelioid lung cell line and the methylthiazol tetrazolium (MTT) bioass ay were used to investigate the cytotoxicity of AFB(1) and its chemically s ynthesised epoxide (AFBO) in vitro. Statistical analysis of the MTT results indicated that there were overall significant differences between the cont rol and both the AFB(1)-treated (p < 0.0001) and AFBO-treated cells (p = 0. 00 2). However, there was no significant difference between AFB(1) and AFBO -treated cells, when the entire range of concentrations were assessed again st each other (p = 0.2877). When analysed at each concentration, only at 0. 01 mM was there a significant difference between the effects of AFB(1) and AFBO (p = 0.0358). The results of this investigation show that AFB(1) and A FBO are both cytotoxic in the A549 cell line.