Ferroptosis is closely associated with the pathophysiology of myocardial ischemia. Hydroxysafflor yellow A (HSYA), the main active ingredient in the Chinese herbal medicine safflower, exerts significant protective effects against myocardial ischemia/reperfusion injury (MI/RI). The aim of this study was to investigate the protective effects of HSYA against MI/RI and identify the putative underlying mechanisms. An in vivo model of acute MI/RI was established in C57 mice. Subsequently, the effects of HSYA on myocardial tissue injury were evaluated by histology. Lipid peroxidation and myocardial injury marker contents in myocardial tissue and serum and iron contents in myocardial tissue were determined using biochemical assays. Mitochondrial damage was assessed using transmission electron microscopy. H9C2 cardiomyocytes were induced in vitro by oxygen–glucose deprivation/reoxygenation, and ferroptosis inducer erastin was administered to detect ferroptosis-related indicators, oxidative-stress-related indicators, and expressions of ferroptosis-related proteins and HIF-1α. In MI/RI model mice, HSYA reduced myocardial histopathological damage, ameliorated mitochondrial damage in myocardial cells, and decreased total cellular iron and ferrous ion contents in myocardial tissue. HSYA increased the protein levels of SLC7A11, HIF-1α, and GPX4 and mitigated erastin- or HIF-1α siRNA-induced damage in H9C2 cells. In summary, HSYA alleviated MI/RI by activating the HIF-1α/SLC7A11/GPX4 signaling pathway, thereby inhibiting ferroptosis.

Background: Hydroxysafflor Yellow A (HSYA), the major bioactive component from Carthamus tinctorius L., exerts significant protective effects against myocardial ischemia-reperfusion injury (MIRI). Mitophagy is pivotal in the pathological process of MIRI, yet the specific molecular mechanism underlying HSYA-mediated mitophagy regulation remains unclear. Objective: This study aimed to investigate the association between HSYA treatment and mitochondrial autophagy in murine MIRI and to explore the potential mechanistic role of the SIRT1-FOXO3-BNIP3 signaling pathway using functional loss-of-function and rescue experiments. These findings may provide preliminary evidence supporting the clinical translational potential in MIRI therapy. Methods: Mouse myocardial ischemia-reperfusion injury (MIRI) model and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced AC16 cardiomyocyte injury models were established. Metabolomics, molecular docking, and surface plasmon resonance (SPR) techniques were combined to screen the potential targets of HSYA. The SIRT1 inhibitor EX527 and SIRT1 siRNA were used to verify the underlying mechanism. Cardiac function, myocardial infarct size, mitochondrial function, the expression of autophagy-related proteins, and protein–protein interaction were detected and analyzed. Results: Compared with the MIRI group, HSYA significantly improved cardiac function in mice, as evidenced by increased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) (p < 0.01), attenuated ST-segment elevation, and improved myocardial perfusion. HSYA also markedly reduced myocardial infarct size (p < 0.01) and serum levels of CK-MB, LDH, and cTnI (all p < 0.01) and ameliorated myocardial histopathological damage and mitochondrial ultrastructural integrity. Mechanistic studies revealed that HSYA significantly upregulated the expression of SIRT1, FOXO3, BNIP3, Beclin-1, and the LC3II/I ratio while downregulating p62 expression (p < 0.01), consistent with enhanced mitophagy-related activity. Furthermore, these protective effects were markedly attenuated upon SIRT1 inhibition or siRNA-mediated silencing, whereas HSYA intervention partially reversed these alterations. Additionally, co-immunoprecipitation (Co-IP) and pull-down assays demonstrated that HSYA promoted protein–protein interactions between SIRT1-FOXO3, FOXO3-BNIP3, and BNIP3-LC3B. Conclusions: These findings highlight that HSYA is associated with improved cardiac function, enhanced mitophagy-related activity, and upregulated SIRT1-FOXO3-BNIP3 signaling, providing robust experimental evidence for its clinical translational application in MIRI treatment.