Congenital heart disease (CHD) is the most prevalent type of anatomical malformation present at birth, affecting 0.8–1% of live-born infants, and its global prevalence is on the rise (Liu et al., 2019). Despite its high frequency, the underlying causes of CHD remain largely unknown (Huhta and Linask, 2013). While genetic factors contribute to approximately 15% of CHD cases, there is increasing recognition of the environmental factors that may play a significant role, with up to 30% of cases linked to environmental influences, including high temperatures, radiation, noise, medications, as well as biological factors such as viruses, bacteria, and parasites (Liu et al., 2013; Liang et al., 2017). One of the environmental pollutants associated with the factors mentioned above is cyprodinil, a pyrimidine amine pesticide widely used in the cultivation of vegetables, fruits, and rice. Its widespread use is driven by its effectiveness in combating gray mold in agricultural settings (Chen et al., 2016). Notably, cyprodinil has been detected in aquatic environments at concentrations ranging from 0.73 µg/L to 2.89 µg/L, indicating its potential for environmental exposure (Tang et al., 2020). Increasing evidence suggests that cyprodinil, acting as an agonist for the aryl hydrocarbon receptor (AhR), exerts detrimental effects on cardiac development, raising concerns about potential cardiac developmental injuries associated with cyprodinil exposure (Fang et al., 2013). This highlights the significance of understanding the impact of cyprodinil on cardiac development.
However, the current approach to treating pesticide-induced cardiac damage has certain limitations. For instance, the management of cardiotoxicity resulting from organophosphorus and carbamate pesticide poisoning primarily involves maintaining vital signs, including mechanical ventilation, decontamination procedures to prevent further uptake, and the administration of anti-nicotinic and muscarinic agents. However, there is a notable absence of a specific treatment protocol for toxicity caused by organochlorine pesticides, glyphosate herbicides, or bipyridyl herbicides. Consequently, the management of poisoning caused by these substances is largely restricted to decontamination measures, aggressive symptomatic care, and supportive treatment, as no known antidote has been identified (Anakwue, 2019). Therefore, the search for a natural product that can effectively mitigate pesticide-induced cardiotoxicity is of immense significance and warrants further research.
(-)-Epicatechin-3-gallate (ECG), a flavonoid organic compound found in green tea (Camellia sinensis), has attracted significant attention for its potential in addressing various health issues. Flavonoids, as a common and diverse group of polyphenols, possess strong antioxidant properties due to the presence of numerous hydroxyl groups in their molecules (Cardoso et al., 2020; Steinmann et al., 2013). Unfermented green tea is the richest source of catechins, although they are also naturally occurring in black tea, coffee, berries, grapes, and wine. Research has uncovered diverse biological effects of ECG, including antioxidant, anti-inflammatory, anti-viral, anti-bacterial, anti-aging, and hypotensive properties (Leung et al., 2001; Zhang et al., 2018; Beltz et al., 2006; Jigisha et al., 2012; Ahmad and Makhtar 1999). ECG has also shown promise in cancer prevention, with potential benefits for lung, esophagus, stomach, intestinal, pancreatic, breast, prostate, and bladder cancers (Gupta et al., 2014; Masek et al., 2017; Singh et al., 2011; Bernatoniene and Kopustinskiene 2018). Notably, ECG has been extensively researched for its protective effects on the heart. It has demonstrated the ability to protect against ischemia/reperfusion (I/R) injury by modulating Na/K-ATPase/Src receptor function (Qi et al., 2019). Furthermore, ECG has also been reported to protect against heart toxicities caused by doxorubicin and nitric oxide, as well as in the context of coronary heart disease and post-myocardial infarction (Cai et al., 2015; Paquay et al., 2000; Mukhtar and Ahmad 2000; Ravindran et al., 2022). While the cardioprotective effects of ECG have been acknowledged, a comprehensive understanding of the underlying mechanisms is yet to be fully elucidated.
Zebrafish (Danio rerio) is a non-mammalian vertebrate model that has gained prominence in developmental genetics, functional genomics, and cardiac morphology-function studies (Genge et al., 2016; Coppola et al., 2023). This is attributed to the transparency of their larval stages, which allows for the easy observation of critical developmental milestones and direct examination of the heart (Chang et al., 2023). One key advantage of using zebrafish as a research model is the similarity between their genome and that of humans (Bakkers 2011). Additionally, zebrafish have a high reproductive capacity, making them cost-effective to maintain. Importantly, zebrafish share essential similarities with humans in terms of cardiac physiology, including fundamental contractile dynamics. As a result, zebrafish have emerged as a robust model for investigating channelopathies and cardiomyopathies, offering valuable insights into cardiac function (Bakkers 2011).
In this study, we aimed to investigate the potential protective role of ECG against the detrimental effects of cyprodinil on zebrafish development and to elucidate the underlying mechanistic pathways involved. Zebrafish embryos were exposed to cyprodinil with and without ECG, and our results revealed a significant mitigation of cyprodinil-induced developmental dysfunction in zebrafish embryos in the presence of ECG. Notably, ECG exerted a strong influence on various developmental parameters, including embryonic movement, hatching rate, pericardial anomaly, and tachycardia, acting as a potent protective agent against the adverse effects of cyprodinil. Furthermore, our study explored the molecular mechanisms underlying these protective effects. We found that ECG effectively counteracted cyprodinil-induced alterations in mRNA expression, particularly those involved in cardiac development and calcium channels. Intriguingly, our research also uncovered the potential inhibitory effect of ECG on AhR signaling pathways, which were upregulated by cyprodinil. This work not only demonstrated the protective potential of ECG against cyprodinil but also provided insights into a novel approach for enhancing the regulation and safe use of this chemical compound. By harnessing the synergistic benefits of ECG, a natural small molecule, we propose an innovative strategy with promising implications for promoting the safe use of cyprodinil.