Effects of sunset yellow FCF on immune system organs during different chicken embryonic periods

Introduction: Sunset Yellow FCF (SY), used frequently in ready-made foods, cosmetics, and the pharmaceutical industry, may cause many health problems. This study is intended to evaluate the morphological and cellular effects of SY on the embryonic chicken immune system throughout incubation. Material and Methods: Babcock white leghorn eggs were randomly divided into four groups. Besides a control group, there were three treatment groups which received a single injection of 200, 1,000, or 2,000 ng of SY into the air sac just before incubation. The eggs were opened on the 10th, 13th, 16th, and 21st days of incubation. Samples of the bursa of Fabricius, thymus, and spleen were taken from embryos. Serial sections of 5 mu m thickness were stained with histological methods and routine histological procedures were performed. Results: An increase in the spleen volume was determined as the hatching time of the chicks approached. The highest eosinophil ratio was found in the SY1,000 and SY2,000 groups (P < 0.05), where the most significant change was developmental retardation in the thymus. In the bursa of Fabricius, there was less lymphocyte accumulation and eosinophilic cell infiltration with increasing doses. Conclusion: It was concluded that in ovo administered SY has undesired effects on embryonic development of the bursa of Fabricius, spleen, and thymus, and on spleen volume.