The food dye Tartrazine disrupts vascular formation both in zebrafish larvae and in human primary endothelial cells

Abstract

Tartrazine (E102) is a controversial coloring agent whose potential impacts on human health are not fully understood. Our study reveals the vascular disrupting effects of tartrazine (TTZ) on developing zebrafish embryos in vivo and on human umbilical vein endothelial cells in vitro. The dye was shown to cause dose-dependent hemorrhages in zebrafish embryos. Analyzing transgenic zebrafish harboring fluorescent endothelial cells revealed that TTZ treatment disrupted cell organization into vessels in both the sub-intestinal vein and the brain area. Assays on human umbilical vein endothelial cells demonstrated that TTZ inhibited endothelial proliferation, tube formation, and migration in a dose-dependent manner. Taken together, our results indicate for the first time that TTZ can affect endothelial cell properties, possibly by disrupting Rho family GTPase pathways which control the cytoskeleton. Our finding provides a credible explanation for many reported human health impacts and offers prospective applications for biomedicine.

Keywords: BMP pathways; Blood vessels, Zebrafish; HUVEC; Rho GTPases; Tartrazine.

Fig. 1

ZET results for TTZ. (A) Dose-response curves showing survival and occurrence of any malformation induced by 96 h TTZ exposure, X-axis is logarithmically scaled. (B) A control embryo at 4 dpf showing normal morphology. (C) Hemorrhagic sites (arrowheads) induced by TTZ exposure. (D) Percentages of surviving embryos with different phenotypes at 4 dpf (Standard Deviations were excluded for visual clarity). (E) Severe deformities at high TTZ concentration.

Fig. 2

Vascularization analysis on transgenic fluorescent zebrafish lines.  (A) Cephalic vessel and caudal venous plexus vascularization are dose-dependently affected by TTZ; Vessels appear to be increasingly merged/clumped together instead of forming distinguishable fine structures; Notably , the three-longitudinal-vessel pattern in the CVP gradually merged (5 g/L) into a two-vessel pattern (10 g/L). (B) Normal (basket-shaped) and ectopically sprouted (arrowheads) SIV formation. (C) Percentages of ectopic sprouting at different TTZ concentrations.

Fig. 3

TTZ inhibits HUVEC angiogenic activities in a dose-dependent manner.  (A) TTZ inhibits HUVEC proliferation in the BrdU assay. (B-D) TTZ treatment leads to reduced tube extension and branching during tubulogenesis. (E-F) Wound healing assay showing anti-migratory effect of TTZ. Concentrations are log-scaled , and biological replicates are represented using different colors. Asterisks denote statistical significance: *p < 0.01; **p < 0.001.