[Qingdu Wenxin Formula mitigates doxorubicin-induced cardiotoxicity via inhibition of cGAS/STING/NF-κB...

To investigate the protective effect and mechanism of Qingdu Wenxin Formula(QD-WXF) against doxorubicin-induced cardiotoxicity(DIC), as well as the regulatory effect of QD-WXF on the cyclic guanosine monophosphate-adenosine monophosphate synthetase(cGAS)/stimulator of interferon genes(STING)/nuclear factor(NF)-κB signaling pathway. C57BL/6J mice were randomized into control, model, pravastatin(40 mg·kg~(-1)), and low-(1.3 g·kg~(-1)), medium-(2.6 g·kg~(-1)), and high-dose(5.2 g·kg~(-1)) QD-WXF groups. The mouse model of DIC was established through tail vein injection of doxorubicin, followed by four weeks of gavage. The cardiac function was evaluated by echocardiography, lactate dehydrogenase(LDH) assay, and troponin Ⅰ(TNⅠ) assay. Myocardial histopathology was assessed via hematoxylin-eosin and Masson's trichrome staining. RT-qPCR was conducted to measure the mRNA levels of interleukin(IL)-6, tumor necrosis factor(TNF)-α, and IL-1β in the cardiac tissue. Network pharmacology and molecular docking were employed to predict key pathways associated with QD-WXF and DIC, while Western blot to assess the protein level of STING. The mice with STING knockout(STING~(KO)) were prepared to validate the expression changes of proteins involved in the STING pathway and inflammation. The results of the animal experiment showed the low, medium and high doses of QD-WXF increased the ejection fraction(EF) and fractional shortening(FS) to different extents, reduced the myocardial injury markers LDH and TNⅠ, down-regulated the mRNA levels of IL-6, IL-1β, and TNF-α in the cardiac tissue, significantly reduced the inflammatory cells, recovered the regular arrangement of myocardial cells, and decreased the area of perivascular fibrosis. The high-dose group of QD-WXF had the best effect. According to the prediction results of network pharmacology and molecular docking, the key pathway between QD-WXF and DIC was the STING pathway. In addition, QD-WXF up-regulated the level of phosphorylated STING(p-STING)/STING. In the STING~(KO) mouse experiment, the results of cardiac function evaluation and inflammatory index detection of the wild type(WT) group were consistent with those of C57BL/6J mice. QD-WXF downregulated the protein levels of phosphorylated TANK-binding kinase 1(p-TBK1), phosphorylated interferon regulatory factor 3(p-IRF3), and phosphorylated nuclear factor κB(p-NF-κB). In the experiment with STING~(KO), there was no significant difference between the QD-WXF group and the model group, while significant differences existed between the WT model group and the STING~(KO) model group. The above results indicate that QD-WXF can effectively alleviate doxorubicin-induced cardiotoxicity by inhibiting the inflammation via the cGAS/STING/NF-κB pathway.