Aflatoxin M1 effects on Xenopus laevis development.
BACKGROUND
The principal Aflatoxin B(1) (AFB(1)) hydroxylated metabolite excreted in milk is Aflatoxin M(1) (AFM(1)) classified in group 2B by the International Agency for Research on Cancer (IARC). Human exposure to AFM(1) is due to the consumption of contaminated dairy products and partly to endogenous production through AFB(1) liver metabolism.


METHODS
Since no data are available on AFM(1) embryotoxicity, its lethal and teratogenic potential was investigated using the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). Stage-8 blastulae were exposed to AFM(1) at 1, 4, 16, 64, and 256 microg/L concentrations until stage 47, free-swimming larva.


RESULTS
A slight increase of mortality and malformed larva percents was found in AFM(1)-exposed groups but these differences were not statistically significant in comparison with the controls.


CONCLUSIONS
Therefore, AFM(1) is a non-embryotoxic compound when evaluated with a FETAX model at concentrations under the conditions tested. However, AFM(1) merits further studies using mammals as experimental models to identify a possible risk during human pregnancy.
Vismara
Claudio
C
Department of Biology, University of Milan, Milan, Italy. claudio.vismara@unimi.it
Di Muzio
Andrea
A
Tarca
Silvia
S
Lucchino
Marta
M
Foti
Ingrid
I
Caloni
Francesca
F
D016607:Aflatoxin M1 / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects* / Q000196:embryology; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D014982:Xenopus laevis / Q000196:embryology* / Q000254:growth & development*
D016607:Aflatoxin M1