Further studies on protective effects of vitamins in cyclophosphamide-induced cleft palate

The effects of vitamins B1, B6, and E administered 1 day before and simultaneously with an embryotoxic dose of cyclophosphamide (CPM) were studied using random-bred mice ICR (VELAZ). A single dose of 20 mg/kg CPM administered i.p. or i.m. on day 12 of pregnancy induced in the foetuses cleft palate and malformations of the upper and lower limbs. Both vitamins B1 and B6 decreased nonsignificantly the overall proportion of malformed foetuses and changed the spectrum of malformations, the decrease in foetuses with malformed upper limbs being statistically significant. In the groups supplemented with vitamins the mean foetal weight was higher in litters without malformed upper limbs than in litters with malformed upper limbs and those of both types in the control group. Similar effects of vitamin E were statistically nonsignificant. It is most likely that vitamins influence the pharmacokinetics of cyclophosphamide or its metabolites. The data provided offer no explanation for the claimed beneficial effects of vitamins for preventing the occurrence of orofacial clefts in patients at risk.