Huoxin pill protects verapamil-induced zebrafish heart failure through inhibition of oxidative stress-triggered inflammation and apoptosis

Heart failure (HF) is a major and growing public health concern. Although advances in medical and surgical therapies have been achieved over the last decades, there is still no firmly evidence-based treatment with many traditional Chinese medicines (TCMs) for HF. Huoxin Pill (HXP), a TCM, has been widely used to treat patients with coronary heart disease and angina pectoris. However, the underlying molecular mechanism is poorly understood. In this study, using a verapamil-induced zebrafish HF model, we validated the efficacy and revealed the underlying mechanism of HXP in the treatment of HF. Zebrafish embryos were pretreated with different concentrations of HXP followed by verapamil administration, and we found that HXP significantly improved cardiac function in HF zebrafish, such as by effectively alleviating venous congestion and increasing heart rates. Mechanistically, HXP evidently inhibited verapamil-induced ROS and H₂O₂ production and upregulated CAT activity in HF zebrafish. Moreover, transgenic lines Tg(mpx:EGFP) and Tg(nfkb:EGFP) were administered for inflammation evaluation, and we found that neutrophil infiltration in HF zebrafish hearts and the activated NF-kB level could be reduced by HXP. Furthermore, HXP significantly downregulated the level of cell apoptosis in HF zebrafish hearts, as assessed by AO staining. Molecularly, RT‒qPCR results showed that pretreatment with HXP upregulated antioxidant-related genes such as gpx-1a and gss and downregulated the expression of the stress-related gene hsp70, proinflammatory genes such as tnf-α, il-6 and lck, and apoptosis-related indicators such as apaf1, puma and caspase9. In conclusion, HXP exerts a protective effect on verapamil-induced zebrafish HF through inhibition of oxidative stress-triggered inflammation and apoptosis.