Folic acid and soybean isoflavone combined supplementation protects the post-neural tube closure defects of rodents induced by cyclophosphamide in vivo and in vitro

To evaluate the neuroprotective effect of folic acid (FA) and soybean isoflavone (SIF) combined supplementation on the post-neural tube closure of rodents induced by cyclophosphamide (CPA) in vitro and in vivo, pregnant rats were randomly divided into control, model, solo-FA intervention, solo-SIF intervention and co-intervention of FA and SIF groups. Rats in solo-intervention groups and cointervention group were treated with FA 0.7 mg/kg, SIF 160 mg/kg and FA 0.7 mg/kg + SIF 160 mg/kg at the duration of pregnancy, respectively. On the 13th day of gestation, control rats were given physiological saline and the other four groups were treated with CPA12.5 mg/kg. On the 14th day of gestation, three rats selected randomly from every group were executed and the ultrastructure, DNA damage and the proteins expressions of Bcl-2, Bax and P53 on embryo brains were checked. The rest of the rats were executed on the 20th day, the frequency of neural tube closure defects and fetus' development indices were measured. In addition, T-SOD, MDA and NO in serum of the pregnant rats were checked. In vitro, the effect of FA and genistein on the apoptosis was determined. Compared with the model group, the malformation incidence was lower but fetus' development indices were higher in the combination treated group. The combination decreased the damage of CPA, such as damaged nuclear DNA, early apoptotic morphological changes, Bax and P53 expressions on embryo brains and in vivo. Furthermore, T-SOD activity in serum of the pregnant rats increased and the levels of MDA and NO decreased in the combined supplementation group. Our study indicates the neuroprotection of FA and SIF combined administration is superior to solo treatment. Decrease of DNA damage and neuron apoptosis involved in the mechanisms. Furthermore, the up-regulation of Bcl-2 and the down-regulation of Bax and P53 proteins also participate in the effect. (C) 2010 Elsevier Inc. All rights reserved.