Fumonisin B₁ induced neural tube defects were not increased in LM/Bc mice fed folate-deficient diet

Scope: Fumonisin B₁ (FB₁) is found in corn-based foods and is a possible risk factor for neural tube defects (NTDs). The mechanism(s) underlying NTD induction by FB₁ in LM/Bc mice is not understood; however, evidence suggests disrupted folate transport is involved. Methods and results: Female LM/Bc mice were fed folate-sufficient (control) or folate-deficient diet beginning 5 wk before mating, treated with 0 (vehicle), 2.5 or 10 mg/kg FB₁ by intraperitoneal injection on embryonic days 7 (E7) and E8, and their fetuses examined on E16. Dose-dependent NTD induction was found in groups fed the control diet: 3 of 13 low-dose and 10 of 11 high-dose litters were affected. Among groups fed folate-deficient diet, NTDs were found only in 4 of 11 high-dose litters. In another trial, consumption of folate-deficient diet also resulted in fewer NTDs at a dose of 10 mg/kg FB₁ and reduced maternal red blood cell folate levels by 80%. In utero death did not fully account for the differences in NTD rates. Conclusion: Folate deficiency does not exacerbate NTD induction by FB₁ in LM/Bc mice. Interactions between folate, other nutritional factors, and FB₁ in this mouse model for NTDs are complex and require further investigation.