A Novel’s Evidence of MSG-Induced Craniofacial Defects in Chick Embryo Models

Monosodium glutamate (MSG), commonly used as an additive food enhancer, has been reported to have teratogenic effects on the embryo during development. The present study aimed to investigate the effect of MSG-induced teratogenicity, focusing on craniofacial formation in the chick embryo model. One hundred eighty fertilized eggs were divided into control and MSG groups. The chemicals were administered, and the results were investigated in 3-day-old embryos (ED-3), ED-6, and ED-10. The morphology and histology of craniofacial structures were studied using a stereomicroscope and light microscopy. The neural crest cells (NCCs) were investigated by the immunostaining technique. The results showed that a dose of 3 mg of MSG induced anterior neuropore opening and eye malformation in ED-3, and this was clearly demonstrated in ED-6. MSG also caused craniofacial bone malformation and delayed calcification in ED-10. Moreover, MSG induced apoptosis of NCCs and reduced the proliferation of NCCs in the craniofacial structures. These findings are the 1st report to demonstrate the teratogenicity of high doses of MSG-induced craniofacial defects in chick embryos during organogenesis. HIGHLIGHTS Monosodium glutamate exposure causes craniofacial defects in chick embryos. The functions of the neural crest cells were abrogated due to monosodium glutamate-induced teratogenesis, which led to birth defects. The experimental protocols benefit teratogenicity studies, and the results can be applied to future studies to elucidate the causes of birth defects during organogenesis. GRAPHICAL ABSTRACT