Toxicity Assessment of 4 Azo Dyes in Zebrafish Embryos

Abstract

Azo dyes are used widely as color additives in food, drugs, and cosmetics; hence, there is an increasing concern about their safety and possible health hazards. In the present study, we chose 4 azo dyes tartrazine, Sunset Yellow, amaranth, and Allura red and evaluated their developmental toxicity on zebrafish embryos. At concentration levels of 5 to 50 mM, we found that azo dyes can induce hatching difficulty and developmental abnormalities such as cardiac edema, decreased heart rate, yolk sac edema, and spinal defects including spinal curvature and tail distortion. Exposure to 100 mM of each azo dye was completely embryolethal. The median lethal concentration (LC50), median effective concentration (EC50), and teratogenic index (TI) were calculated for each azo dye at 72 hours postfertilization. For tartrazine, the LC50 was 47.10 mM and EC50 value was at 42.66 mM with TI ratio of 1.10. For Sunset Yellow, the LC50 was 38.93 mM and EC50 value was at 29.81 mM with TI ratio of 1.31. For amaranth, the LC50 was 39.86 mM and EC50 value was at 31.94 mM with TI ratio of 1.25. For Allura red, the LC50 was 47.42 mM and EC50 value was 40.05 mM with TI ratio of 1.18. This study reports the developmental toxicity of azo dyes in zebrafish embryos at concentrations higher than the expected human exposures from consuming food and drugs containing azo dyes.

Effects of the food colorant carmoisine on zebrafish embryos at a wide range of concentrations

“…The embryo maintains the osmotic balance in the water environment it is in, thanks to a water barrier in the yolk sac (Sant and Timme-Laragy 2018). It has been reported that azo dyes, due to their high water solubility properties, may disrupt this osmotic balance and cause excessive water intake into the embryo and, as a result, edema formation (Jiang et al 2020). Indeed, a study (Gupta et al 2019) reported that a large yolk sac was observed in zebrafish embryos exposed to erythrosine which is another azo dye due to deformities or delayed bone development.…”

Toxicological and ecotoxicological aspects of tartrazine yellow food dye: a literature review

“…Joshi and Katti (2017) found a value of the unobserved effect concentration (CENO) and lethal concentration (CL (I) 50, 96 h) of 5 (2.67 gL -1 ) and 29.4 mM, respectively (15.7 gL -1 ). Jiang et al (2020) found the CL (I) 50, 96 h value of 47.10 mM (25.1 g.L -1 ). Of these papers, those of Gupta et al (2019) and Silva and Fracácio (2020) described deformities that were found in the embryonic and larval development of D. rerio, suggesting that the tartrazine dye, once released into the aquatic environment, compromises aquatic life (Table 2).…”

Microbial degradation of dyes: An overview

“…This increases concern related to health and safety. Global usage of azo dye as food additive is being regulated (Jiang et al, 2020). Azo dye toxicity is based on benzidine and its counterpart like dimethoxy-and dimethylbenzidine.…”