Evaluation of the cytogenetic activity of the food dye Azorubine in a micronucleus test in mice

Introduction. Azorubine E122 (Carmoisine, Food Red 3) monoazo dye is used in the manufacture of desserts, caramels, sweets, marmalades, ice cream, alcoholic and non-alcoholic drinks, etc. The safety assessment of food additives includes the study of genotoxic potential. At the same time, for substances with a high or a small but long-term exposure (including food additives), in vivo tests are required.

Materials and methods. The genotoxic activity of aqueous solutions of synthetic food azo dyes E122 Azorubin was studied by the micronuclear method on bone marrow cells in mice (males, hybrids F1 CBA × C57Bl6/j). The studied substances were injected into the stomach of mice at doses of 250–2000 mg/kg twice with an interval of 24 hours, with the preparation of bone marrow preparations 24 hours after the last administration. The frequency of micronucleated (MN) polychromatophilic erythrocytes (PCEs) was estimated on the base of the results of the analysis of 4000 PСЕ. The proportion of PСE among all red blood cells was determined by analyzing 500 cells per animal.

Results. There was no statistically significant increase in the frequency of PCE with MN over the current control with a double administration of Azorubine in all studied doses. After exposure at doses of 1000 and 2000 mg/kg, the incidence of MN PCEs slightly exceeded the upper limit of the 95% CI of the accumulated negative control and the effect was dose-dependent and statistically significant, which does not allow recognizing the answer as clearly negative.

Limitations of the study are due to the methodology of the test: only cytogenetic disorders in a single tissue were analyzed under conditions of double enteral administration of the studied sample.

Conclusion. An analysis of the frequency of MN PCEs in the bone marrow of mice after a double injection of Azorubine at doses of 250–2000 mg/kg made it possible to qualify the result of the experiment as uncertain.

Compliance with ethical standards. The study was approved by the local ethical committee of the Research Institute of EDiTO Federal State Budgetary Institution «N.N. Blokhin National Medical Research Center of Oncology» of the Ministry of Health of the Russian Federation, carried out under the European Convention for the Protection of Vertebrate Animals Used for Experiments or Other Scientific Purposes (ETS N 123), Directive of the European Parliament and Council of the European Union 2010/63/EU of 22.09.2010 on the protection of animals used for scientific purposes.

Contribution:
Yurchenko V.V. — concept and design of the study, work with animals, preparation of preparations for cytogenetic analysis, statistical analysis, analysis of literature, writing a text;
Akhaltseva L.V. — cytogenetic analysis, search for literature sources, analysis of literature;
Konyashkina M.A. — work with animals, preparation of preparations for cytogenetic analysis, cytogenetic analysis, search for literature sources;
Yurtseva N.A. — work with animals, preparation of preparations for cytogenetic analysis, search for literature sources.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Acknowledgment. The work was carried out within the framework of the state task «Complex system for assessing the genotoxicity of food additives» Centre for Strategic Planning of FMBA of Russia.

Conflict of interest. The authors declare no conflict of interest.

Received: February 6, 2023 / Accepted: June 7, 2023 / Published: July 30, 2023