The extreme sensitivity of turkeys to
aflatoxin B(1) (AFB(1)) is associated with efficient hepatic
cytochrome P-450 (P450)-mediated bioactivation, and deficient
glutathione S-transferase (GST) mediated detoxification.
Butylated hydroxytoluene (
BHT) protects against AFB(1) toxicity in turkeys through mechanisms that include competitive inhibition of P450-mediated AFB(1) bioactivation. To test whether dietary
BHT alters hepatic AFB(1)-DNA adduct formation, excretion, and bioavailability of AFB(1)in vivo, turkeys were given diets with
BHT (4000ppm) for 10 days, given a single oral dose of [(3)H]-AFB(1) (0.05microg/g; 0.02microCi/g), then sampled at intervals up to 24h. Radiolabel in serum, red blood cells, liver, and breast meat was frequently lower in
BHT-treated compared to control. Hepatic AFB(1)-DNA adducts in
BHT-treated turkeys were significantly lower at 12 and 24h.
BHT-fed birds had significant higher bile efflux, though biliary radiolabel excretion was not different from control. The amount of
aflatoxin M(1) (AFM(1)) excreted in the bile was lower than in control, but
BHT had no effect on the biliary excretion of AFB(1),
aflatoxin Q(1) or
glucuronide and
sulfate conjugates. Thus, the chemopreventive properties of
BHT may also occur through a reduction in AFB(1) bioavailability in addition to inhibition of bioactivation.