Numerous studies have established that
aflatoxin is a potent developmental toxin in animals. Previous research has demonstrated that a phyllosilicate
clay,
hydrated sodium calcium aluminosilicate (
HSCAS or Novasil), tightly binds and immobilizes
aflatoxins in the gastrointestinal tract of animals and markedly reduces the bioavailability and toxicity of
aflatoxin. Our objective in this study was to utilize the pregnant rat as an in vivo model to compare the potential of
HSCAS and
bentonite to prevent the developmental toxicity of
aflatoxin. Aluminosilicates (
HSCAS) and
bentonite were added to the diet at a level of 0.5% (w/w) and fed to the pregnant rat throughout pregnancy (i.e. days 0-20). Test animals were fed an
aflatoxin-contaminated diet (2.5 mg kg(-1) diet) with or without sorbents during gestation days 6-15. Evaluations of toxicity were performed on day 20. These included maternal (mortality,
body weights, feed intake and litter weights), developmental (embryonic resorptions and
fetal body weights) and biochemical (ALT, AST and AP) evaluations. Sorbents alone were not toxic and
aflatoxin alone resulted in significant maternal and developmental toxicity. Animals treated with phyllosilicate (plus
aflatoxin) were comparable to controls following evaluations for resorptions, live fetuses and
fetal body weights, as well as biochemical parameters. While
bentonite plus
aflatoxin resulted in significant reduction in
fetal body weight, none of the fetuses from
HSCAS or
bentonite plus
aflatoxin-treated groups had any gross, internal soft tissue or major skeletal malformations.