Evaluation of Embryotoxicity of Radix scutellariae Based on Embryonic Stem Test
Purpose: To determine the potential embryotoxicity of Radix scutellariae (RS) extract using an embryonic stem cell test (EST) and to evaluate its effect on the differentiation of mouse embryonic stem (ES) cells.
Methods: All the test samples were obtained by water extraction method. The embryotoxicity of RS was assessed with cytotoxicity assays, namely, embryonic stem (ES) cells (IC50ES) and 3T3 fibroblasts (IC503T3), as well as cardiac differentiation inhibition assay (ID50ES). The expression of specific genes and proteins was analyzed by quantitative reverse transcription – polymerase chain reaction (RT-PCR) and Western blot.
Results: RS was weakly embryotoxic with IC50ES, IC503T3 and ID50ES of 0.1524, 0.1061, and 0.4169 mg/ml, respectively. Also RS had discordant effects on the expression of tissue-specific genes and proteins in three germ layers, promoting differentiation of the ectoderm (⋆p < 0.05; ⋆⋆p < 0.01) and endoderm (⋆p < 0.05; ⋆⋆p < 0.01; ⋆⋆⋆p < 0.001), while inhibiting mesoderm differentiation (⋆p < 0.05; ⋆⋆p < 0.01; ⋆⋆⋆p < 0.001). The effect of RS on the embryonic development of the three germ layers was concentration-dependent.
Conclusion: These results indicate that RS possesses weak embryotoxicity. The variability in the effects of RS may be responsible for its weak embryotoxicity.
Keywords: Embryonic stem test, Radix scutellariae, Embryotoxicity, Cardiac differentiation inhibition assay, Ectoderm, Endoderm, Mesoderm