Effect of azithromycin on genotoxicity in Allium test

The effect of azithromycin at a concentration of 50-1000.0 mg/l on the pathology of mitosis in the Allium test in the first metaphase after treatment and after the completion of the recovery period is being investigated. Research methods: Allium test, cytogenetic analysis, statistical analysis. The Allium test was conducted on a batch of the Stuttgarter variety which is genetically unstable as the result of micronucleus test. The results of the analysis showed that the tested concentrations of azithromycin (50.0-1000.0 mg/l) in the first mitosis did not cause a significant increase in the values of mitosis pathology (PM) compared with the negative control. However, there was a significant increase (8 times) in the number of cells with PM in the “aftereffect, after 48 hours” variant for a concentration of 300.0 mg/l of azithromycin: from 4.1% to 32.3%. It should be noted that under the action of all tested concentrations of azithromycin, the same tendency is observed as in the control variant in terms of the preservation of the PM spectrum and the dominance, firstly, of the pathology “overrun/lag of chromosomes”, and secondly, the pathology of “asynchronous spindle fission”. The percentage of mentioned PMs ranges from 52 to 74, and from 7 to 22, respectively. Other types of PMs, according to their occurrence in experimental variants, are arranged in the following sequence: c-mitosis, chromosome scattering, chromosome outliers, polyploidy, chromosome stickiness, chromosomal and chromatid bridges, pycnosis of interphase nuclei. Under the action of azithromycin, starting from a concentration of 100.0 mg/l to 1000.0 mg/l, polyploid cells were observed in dividing cells, which contained a tetraploid set of chromosomes. In experimental variants in single cells, a significant increase in the size of the nuclei of interphase cells and the presence of nuclear buds were noted, which is considered as markers of polyploidization and gene amplification. The recovery period (after 48 hours after the action of the antibiotic) for azithromycin does not reduce the number of cells with PM but changes their composition and spectrum.