Pre-administration of Ganoderma lucidum spore reduces incidence of neural tube defects induced by retinoic acid in pregnant mice

Abstract

To explore whether pre-administration of Ganoderma lucidum spore (GASP) can reduce incidence of neural tube defects (NTDs) induced by all-trans retinoic acid (ATRA) in pregnant mice. Twenty pregnant mice were randomly divided into four groups: normal control group, solvent-treated group, ATRA-induced group, and GASP-treated plus ATRA-induced group. GASP solution, which was prepared with solvent (sodium carboxymethyl cellulose), was fed to the pregnant mice in the GASP-treated plus ATRA-induced group twice a day from embryo (E) 0 d to E10.5 d. The same dose of solvent was given to the pregnant mice in the solvent-treated group. At E7.75 d, ATRA (50 mg/kg) was given to the pregnant mice in both ATRA-induced group and GASP-treated plus ATRA-induced group for single time. Embryos were sampled from pregnant mice at E10.5 d. Then the incidence rate of NTDs in mouse embryo was calculated and the crown-rump length of mouse embryo was measured. The positive rate of nestin expression and the distribution of cell cycle of embryonic neural tube neuroepithelial cells were detected by histochemical staining technique and flow cytometry respectively. Reverse transcription-polymerase chain reaction method was used to detect the gene expressions of cyclin-dependent protein kinase 2 (Cdk2) and Cdk4 mRNAs. The incidence rates of NTDs in mouse embryos in the ATRA-induced group and the GASP-treated plus ATRA-induced group were 79.41% and 21.67% respectively, while the crown-rump length of mouse embryos in these two groups were (3.62+/-1.27) mm and (5.84+/-0.92) mm respectively. The positive rate of nestin expression in embryonic neural tube neuroepithelial cells of mouse embryo at E10.5 d in the ATRA-induced group was 32.44%, while that in the GASP-treated plus ATRA-induced group was 77.65%. The cell cycle of embryonic neural tube neuroepithelial cells was obviously arrested at G(0)/G(1) phase in the ATRA-induced group as compared with that in the GASP-treated plus ATRA-induced group. The Cdk4 mRNA was transcripted at a high level in embryonic neural tube in the GASP-treated plus ATRA-induced group, but the Cdk2 mRNA was not detected in this group. Pre-administration of GASP can reduce the incidence of NTDs induced by ATRA in pregnant mice.