Differential mechanism of toxicity in normal and blood-stasis mice following Rhizoma Curcumae exposure based on "YOU-GU-WU-YUN" theory / 药学学报

ABSTRACT

We were interested in ascertaining differences in developmental neurotoxicity in normal and blood-stasis pregnant mice administered orally Rhizoma Curcumae and the underlying molecular biology mechanisms of any differences. To answer these questions, a blood stasis model was induced by being immersion in ice water. C57BL/6 mice with blood stasis, normal C57BL/6 mice, Nrf2 knock out (KO) mice with blood stasis were randomized into control groups and Rhizoma Curcumae exposure groups. The pregnant mice were administered Rhizoma Curcumae during pregnant day 5 to day 18. The neurodevelopment reflex was examined by the positive occurring time of avoidance precipice reflex tests. Measurement of glutathione (GSH) in brain of the offspring was performed by colorimetric assays. Transcription factor NF-E2-related factor 2 (Nrf2), glutamate cysteine ligase catalytic subunit (GCLc), and glutamate cysteine ligase modifier subunit (GCLm) mRNA and protein expression in brain of the offspring were examined by real-time RT-PCR and Western blot, respectively. All animal care and experiments procedures were reviewed and approved by the Animal Care and Use Committee of Qiqihar Medical College. Our results demonstrated for the first time evidence that C57BL/6 mice treated with Rhizoma Curcumae (10.0 g·kg-1) extended the positive occurring time of avoidance precipice reflex tests of offspring mice compared with the normal control group (P<0.05). We could not find any significant change in that of blood-stasis pregnant mice offspring compared with the normal control group (P>0.05). Compared with the normal control group, level of glutathione, mRNA and protein expression of Nrf2, GCLc, and GCLm significantly increased in brain of the offspring of blood-stasis pregnant mice (all P<0.05). However, mice treated with Rhizoma Curcumae (10.0 g·kg-1) did not change those of offspring (all P>0.05). Knock out Nrf2 using CRISPR/Cas9 extended the positive occurring time of avoidance precipice reflex tests of offspring of blood-stasis pregnant mice (P<0.05). To conclude, developmental neurotoxicity of the blood-stasis pregnant mice to Rhizoma Curcumae was weaker than that of the normal pregnant mice. Cold-induced Nrf2 activation has important roles in "YOU-GU-WU-YUN" phenomenon of Rhizoma Curcumae.