Diosgenin alleviates arsenic trioxide induced cardiac fibrosis by inhibiting endothelial mesenchymal transition.

• Arsenic trioxide induced-EndMT could be reversed by Diosgenin pretreatment. • GR-IL-6 axis is an underlying mechanism for Diosgenin anti-EndMT effects. • Diosgenin is a viable medicine for arsenic cardiotoxicity clinical application. • Confirmed foreground to explore active ingredients recorded in ancient Chinese books. Arsenic trioxide (ATO), the first-line drug in treating acute premyelogenous leukemia, has the profound side effect of inducing endothelial mesenchymal transition (EndMT) and causing cardiac fibrosis. Diosgenin (DIO), a pharmaceutical compound found in Paris polyphylla, exhibits promising potential in safeguarding cardiovascular health by mitigating EndMT. This study aims to explore the role and mechanism of DIO in ATO-induced myocardial fibrosis to provide a novel therapeutic agent for ATO-induced cardiac fibrosis. Wistar rats were given DIO by gavage and ATO by tail vein. Cardiac function and fibrosis were evaluated by echocardiography and Masson's trichrome staining in rats. Human aortic endothelial cells (HAECs) were utilized to analyze ATO-induced EndMT in vitro. The cytoskeleton of HAECs was visualized using F-actin staining to observe cell morphology, while Dil-Ac-LDL staining was employed to assess cell functionality. EndMT-related factors (CD31 and α-SMA), glucocorticoid receptor (GR) and interleukin-6 (IL-6) were detected by immunofluorescence and Western blot in vivo and in vitro. Furthermore, GR was knocked down by si-GR, and IL-6 was blocked by IL-6 neutralizing antibody to verify their role in the effect of DIO on ATO-induced EndMT in HAECs. DIO exhibited significant efficacy in ATO-induced damage to both cardiac diastolic and systolic function, along with mitigating cardiac fibrosis. Additionally, DIO alleviated the loss of cytoskeletal anisotropy and enhanced the uptake of Dil-Ac-LDL in HAECs. Furthermore, it reversed the ATO-induced downregulation of endothelial-specific markers CD31 and GR, while suppressing the upregulation of mesenchymal markers α-SMA and IL-6, both in vivo and in vitro. Notably, the protective effect of DIO was compromised upon knockdown of GR, which also led to a reversal of DIO-induced IL-6 downregulation. Furthermore, the neutralization of IL-6 with specific antibodies abolished the ATO-induced changes related to EndMT. In this study, we clarified the protective effect of DIO on ATO-induced myocardial fibrosis against EndMT via the GR/IL-6 axis for the first time and provided a potential therapeutic agent for preventing heart damage caused by ATO. [Display omitted] [ABSTRACT FROM AUTHOR]