Methylxanthines induce structural and functional alterations of the cardiac system in zebrafish embryos

Abstract

BackgroundZebrafish embryos are emerging as a model for pharmacological and toxicological studies. We used zebrafish embryos to study the general toxicity and cardiovascular effects of eight methylxanthines: aminophylline, caffeine, diprophylline, doxofylline, etophylline, 3-isobutyl-1-methylxanthine (IBMX), pentoxifylline and theophylline.MethodsMicroinjections of the eight methylxanthines were performed in 1-2 cell stage zebrafish embryos and the general toxicity and cardiovascular effects were analyzed at different time points. Embryotoxicity and teratogenicity were evaluated to understand the general toxicity of these compounds. Structural and functional alterations of the heart were evaluated to assess the cardiovascular effects.ResultsOur results showed different activity patterns of the methylxanthines drugs. Caffeine, IBMX, pentoxifylline and theophylline were highly embryotoxic and teratogenic; aminophylline, doxofylline and etophylline were embryotoxic and teratogenic only at higher doses, and diprophylline showed a minimal (<10%) embryotoxicity and teratogenicity. Most of these drugs induced structural alteration of the heart in 20-40% of the injected embryos with the maximum dose. This structural alteration was fatal with the embryos ultimately dying within 120 hpf. All the drugs induced a transient increase in heart rate at 48 hpf which returned to baseline within 96 hpf. This functional effect of methylxanthines showed similarity to the studies done in humans and other vertebrates.ConclusionOur results indicate the potential toxicity and teratogenicity of different methylxanthines in the embryos during embryonic development, the most sensitive period of life. Although interspecies differences need to be considered before drawing any conclusion, our study elucidated that a single exposure of methylxanthines at therapeutic range could induce cardiac dysfunction besides causing embryotoxicity and teratogenicity. Of all the drugs, diprophylline appeared to be safer, with lower degree of embryotoxicity, teratogenicity and cardiac toxicity as compared to other methylxanthines.Electronic supplementary materialThe online version of this article (10.1186/s40360-017-0179-9) contains supplementary material, which is available to authorized users.

Development of a Simple ImageJ-Based Method for Dynamic Blood Flow Tracking in Zebrafish Embryos and Its Application in Drug Toxicity Evaluation

“…The second compound used is IBMX, one of the methylxanthines having coupled heterocyclic organic compounds consisting of pyrimidinedione and imidazole rings [10]. This compound reportedly has two major toxicities, cardiac toxicity and hemodynamic perturbations [9]. In this study, IBMX (160 ppm) caused 58% blood flow velocity reduction.…”

“…On the other hand, IBMX, a methylxanthine increased the heart rate of zebrafish by 12%. Methylxanthines are adenosine receptor antagonists, which cause an increase in the heart rate in the treated embryos [9]. Although IBMX increases the heart rate, it concurrently decreased the blood flow velocity.…”

“…IBMX can cause defective heart formation, irregular heartbeat, decreased blood circulation, mild pericardial and yolk sac edema in zebrafish embryo which explains why it is not approved as a drug. [9].…”

“…A previous study showed that zebrafish incubated in 160 ppm MS222 had a reduced heart rate of 97 bpm [8]. On the other hand, 3-isobutyl-1-methylxanthine (IBMX), one of the most toxic methylxanthines, has been reported to have potent cardiac toxicity and cause severe hemodynamic perturbations [9]. It was also found to have epileptogenic effects in animal studies, although in human studies, an indication of epilepsy was not found [10].…”

Efeito da Adição de teobromina sobre as propriedades do cimento de ionômero de vidro

“…Alguns estudos responsabilizam as metilxantinascomo a teofilina e a cafeína -por mortes acidentais decorrentes de sobredosagem, mas é importante notar que o uso terapêutico desses alcalóides é limitado em virtude de sua ação promotora de arritmias cardíacas e convulsões (74) .…”