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. 2023 Sep 8;24(18):13869.
doi: 10.3390/ijms241813869.

First-Generation Synthetic Cathinones Produce Arrhythmia in Zebrafish Eleutheroembryos: A New Approach Methodology for New Psychoactive Substances Cardiotoxicity Evaluation

Elisabet Teixidó  1   2 , Clara Riera-Colomer  3 , Demetrio Raldúa  4 , David Pubill  3 , Elena Escubedo  3 , Marta Barenys  1   2   5 , Raul López-Arnau  3
Affiliations

First-Generation Synthetic Cathinones Produce Arrhythmia in Zebrafish Eleutheroembryos: A New Approach Methodology for New Psychoactive Substances Cardiotoxicity Evaluation

Elisabet Teixidó et al. Int J Mol Sci. .

Abstract

The increasing number of new psychoactive substances (NPS) entering the illicit drug market, especially synthetic cathinones, as well as the risk of cardiovascular complications, is intensifying the need to quickly assess their cardiotoxic potential. The present study aims to evaluate the cardiovascular toxicity and lethality induced by first-generation synthetic cathinones (mephedrone, methylone, and MDPV) and more classical psychostimulants (cocaine and MDMA) in zebrafish embryos using a new approach methodology (NAM). Zebrafish embryos at 4 dpf were exposed to the test drugs for 24 h to identify drug lethality. Drug-induced effects on ventricular and atrial heart rate after 2 h exposure were evaluated, and video recordings were properly analyzed. All illicit drugs displayed similar 24 h LC50 values. Our results indicate that all drugs are able to induce bradycardia, arrhythmia, and atrial-ventricular block (AV block), signs of QT interval prolongation. However, only MDPV induced a different rhythmicity change depending on the chamber and was the most potent bradycardia and AV block-inducing drug compared to the other tested compounds. In summary, our results strongly suggest that the NAM presented in this study can be used for screening NPS for their cardiotoxic effect and especially for their ability to prolong the QT intervals.

Keywords: QT-interval; cardiotoxicity; new psychoactive substances; synthetic cathinones; zebrafish.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Chemical structures of cocaine and MDMA, as well as the synthetic cathinones MDPV, methylone, and mephedrone.
Figure 2
Figure 2
Chamber-specific beat rate of zebrafish embryos exposed to the five illicit drugs after 2 h. All values represent the mean normalized beat rate versus control ± standard error of the mean (SEM) (n = 10–12 embryos per clutch, at least three clutches were analyzed; * p < 0.05, ** p < 0.01, *** p < 0.001 compared to control values, # p < 0.05, ### p < 0.001 compared between heart chambers (atrium and ventricle)). Two-way ANOVA statistical results are displayed in the graphs.
Figure 3
Figure 3
Graphical representation of the percentage of embryos exposed to each drug concentration presenting AV block (ventricle beating half as often as the atrium), ventricular fibrillation (less than 2.5 times the atrial rate), or none of these effects (regular beating heart 1:1). Fisher’s Exact test * p < 0.05, *** p < 0.001.
Figure 4
Figure 4
Arrhythmicity index (AI) of zebrafish embryos treated with the illicit drugs for 2 h. AI was calculated as the heart period standard deviation normalized to the median heart period. Data points represent the average AI ± standard error of the mean (SEM) (n = 10–12 embryos per clutch, at least three clutches were analyzed; ** p < 0.01, *** p < 0.001 compared to control AI values, # p < 0.05 compared between heart chambers (atrium and ventricle)). Two-way ANOVA statistical results are displayed in the graphs. Data from embryos exposed to 500 µM of cocaine had no ventricle heartbeat; therefore, no AI could be calculated. For that reason, two-way ANOVA was performed considering up to 250 µM of cocaine. For drugs with no statistically significant interaction, significant comparisons between control AI values and treated are displayed, +++ p < 0.001.
Figure 5
Figure 5
Ventricular beat rate of zebrafish embryos exposed to the Cm of the five illicit drugs after 2 h. All values represent the mean normalized beat rate versus control ± standard error of the mean (SEM) (n = 10–12 embryos per clutch, at least three clutches were analyzed; * p < 0.05, ** p < 0.01, *** p < 0.001). t-test statistical results are displayed in the graphs.
Figure 6
Figure 6
Schematic overview of the cardiotoxic effects evaluated in the zebrafish embryo model for MDPV, cocaine, MDMA, mephedrone and methylone. The following values obtained from the zebrafish experiments have been represented for each endpoint: ventricle tachycardia (LOAEC), ventricle bradychardia (EC50), atrium bradychardia (EC50), AV block 2:1 (LOAEC), ventricular fibrillation (LOAEC), arrythmicity index (LOAEC). Grey areas represent in vivo relevant concentrations in humans in blood/plasma after recreative doses described in the literature [47,48], while blue areas represent in vivo relevant concentrations in humans in blood/plasma after lethal doses described in the literature [48,49,50,51].
Figure 7
Figure 7
Schematic representation of the approach used to calculate the interbeat intervals (heart period) from video recordings of zebrafish embryos. Color dots in the bottom right image indicate identified peaks (local maxima, red and minima, green) in data. Methodology adapted from [61].
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References

    1. Baumann M.H., Ayestas M.A., Partilla J.S., Sink J.R., Shulgin A.T., Daley P.F., Brandt S.D., Rothman R.B., Ruoho A.E., Cozzi N.V. The Designer Methcathinone Analogs, Mephedrone and Methylone, Are Substrates for Monoamine Transporters in Brain Tissue. Neuropsychopharmacology. 2012;37:1192–1203. doi: 10.1038/npp.2011.304. - DOI - PMC - PubMed
    1. Cameron K., Kolanos R., Verkariya R., De Felice L., Glennon R.A. Mephedrone and Methylenedioxypyrovalerone (MDPV), Major Constituents of “Bath Salts”, Produce Opposite Effects at the Human Dopamine Transporter. Psychopharmacology. 2013;227:493–499. doi: 10.1007/s00213-013-2967-2. - DOI - PMC - PubMed
    1. Eshleman A.J., Wolfrum K.M., Hatfield M.G., Johnson R.A., Murphy K.V., Janowsky A. Substituted Methcathinones Differ in Transporter and Receptor Interactions. Biochem. Pharmacol. 2013;85:1803–1815. doi: 10.1016/j.bcp.2013.04.004. - DOI - PMC - PubMed
    1. Eshleman A.J., Nagarajan S., Wolfrum K.M., Reed J.F., Swanson T.L., Nilsen A., Janowsky A. Structure-Activity Relationships of Bath Salt Components: Substituted Cathinones and Benzofurans at Biogenic Amine Transporters. Psychopharmacology. 2019;236:939–952. doi: 10.1007/s00213-018-5059-5. - DOI - PMC - PubMed
    1. Lõpez-Arnau R., Martínez-Clemente J., Pubill D., Escubedo E., Camarasa J. Comparative Neuropharmacology of Three Psychostimulant Cathinone Derivatives: Butylone, Mephedrone and Methylone. Br. J. Pharmacol. 2012;167:407–420. doi: 10.1111/j.1476-5381.2012.01998.x. - DOI - PMC - PubMed