The Effects of Citric Acid on Neural Tube Development in Chick Embryos

INTRODUCTION: Neural tube defects (NTDs) are common congenital malformations that cause lifelong disabilities, high medical costs, and significant mortality. This study aimed to evaluate the effects of citric acid, a widely used food additive, on neural tube development in chick embryos.
METHODS: Fertilized, specific pathogen-free chicken eggs were randomly assigned to two groups (n=15 each). Group A (control) received no treatment, whereas Group B received 0.5 mM citric acid injected beneath the embryonic disc at Hamburger–Hamilton stage 9. After 72 h of incubation, embryo survival was recorded, and surviving embryos were examined macroscopically and histopathologically for NTDs. Statistical analysis was performed using Fisher’s exact test.
RESULTS: All embryos in the control group survived (15/15, 100%) and showed normal neural tube development. In the citric acid group, only 10/15 embryos survived (66.7%), and 9/10 (90%) of these exhibited NTDs, mainly cranial and caudal closure failures. Citric acid significantly reduced survival (p<0.05) and increased NTD incidence (p<0.001).
DISCUSSION AND CONCLUSION: Citric acid significantly reduced embryo survival and increased the incidence of NTDs in chick embryos. These findings suggest that citric acid may have embryotoxic and teratogenic effects, highlighting the need for further studies on the safety of widely used food additives during early pregnancy.

Keywords: Chick embryo, citric acid, food additives, neural tube defect, teratogenicity