This study aims to investigate the protective effect of the natural phthalide compound Levistolide A (LA) against myocardial ischemia–reperfusion injury (MIRI) and to elucidate its underlying mechanisms. Utilizing network pharmacology, potential targets of LA in the treatment of MIRI were predicted. Subsequently, a hypoxia/reoxygenation (H/R) model was established using rat H9C2 cardiomyocytes to simulate MIRI, and the mechanisms of action were validated through cellular experiments. Network pharmacology analysis indicated that the potential targets of LA in treating MIRI were significantly enriched in calcium signaling pathways, with the adenosine A2B receptor (ADORA2B), a G protein-coupled receptor (GPCR), identified as a key protein. Cellular experiments demonstrated that 24 μM LA significantly alleviated H/R-induced damage in H9C2 cells, enhanced cell viability, and reduced the release of lactate dehydrogenase (LDH), creatine kinase isoenzyme MB (CK-MB), and cardiac troponin I (cTnI). Pre-treatment with LA significantly activated the ADORA2B/Cyclic adenosine monophosphate (cAMP)/Protein kinase A (PKA) signaling axis, promoting the phosphorylation of phospholamban (PLB), enhancing the activity and protein expression of sarco/endoplasmic reticulum Ca²⁺-ATPase 2 alpha (SERCA2α), and effectively mitigating intracellular calcium overload induced by H/R. However, the ADORA2B antagonist MRS 1754 partially reverses the aforementioned protective effects of LA. The findings of this study reveal a novel mechanism by which LA exerts cardioprotective effects through the ADORA2B/cAMP/PKA/PLB/SERCA2α signaling axis, preventing calcium overload and improving calcium homeostasis, and identify potential candidate compounds and precise targets for the treatment of MIRI.

This study aims to elucidate the active components and underlying molecular mechanisms by which the ethanol-water extract of Cinnamomum migao H.W. Li (MG-EWE) inhibits cardiac fibroblast (CF) transdifferentiation and IL-6 production, providing insights into its anti-myocardial fibrosis effects. The chemical composition of MG-EWE was characterized using UPLC-Q-TOF-MS. Network pharmacology analysis identified active constituents and their mechanisms in inhibiting IL-6 production in CFs. An isoproterenol (ISO)-induced rat CF model was established to evaluate the effects of MG-EWE and its main monomers, Laurolitsine and Hecogenin, on cell proliferation, migration, collagen metabolism, IL-6 production, and key proteins in the ADRB2/JNK signaling pathway. A total of 173 compounds were identified in MG-EWE, with 14 core constituents regulating IL-6 synthesis via 16 key targets, including ADRB2 and MAPK9. Gene Ontology enrichment indicated that MG-EWE affects phosphorylation and the JNK signaling cascade. Molecular docking showed strong binding affinities between Laurolitsine, Hecogenin, and their targets ADRB2 and JNK. Experimentally, MG-EWE, Laurolitsine, and Hecogenin significantly inhibited ISO-induced CF proliferation, migration, and hydroxyproline synthesis, as well as the expression of p-ADRB2, p-JNK, p-c-Jun, and IL-6. MG-EWE inhibits CF transdifferentiation and IL-6 production via the ADRB2/JNK/c-Jun signaling axis, mediated by its constituents Laurolitsine and Hecogenin, highlighting its potential for drug development targeting myocardial fibrosis.

Myocardial ischemia–reperfusion injury (MIRI) significantly limits the clinical benefits of reperfusion therapy, underscoring a pressing need for effective interventions. This study examines the cardioprotective effects and underlying mechanisms of the natural amide alkaloid N-p-trans-Coumaroyltyramine (p-CT). Using hypoxia/reoxygenation (H/R) models in neonatal rat cardiomyocytes and in vivo rat MIRI models, we assessed p-CT pretreatment on cell viability, cardiac function, serum injury markers (lactate dehydrogenase, creatine kinase-MB, cardiac troponin T, and myoglobin), myocardial histopathology, ultrastructural alterations, and infarct size. The systematic screening and validation of potential targets were conducted via label-free quantitative proteomics, molecular docking, and Western blot. The results demonstrated that p-CT pretreatment dose-dependently mitigated H/R-induced cellular injury, improved cardiac function in MIRI rats, reduced serum markers of myocardial damage, alleviated pathological and ultrastructural injury in myocardial tissue, and significantly diminished infarct size. Proteomic analysis revealed 19 differentially expressed proteins specifically reversed by p-CT, with Titin-cap (Tcap) exhibiting the most pronounced downregulation in the MIRI model—a change effectively restored by p-CT pretreatment. Molecular docking indicated strong binding affinity between p-CT and Tcap protein. In summary, p-CT represents a promising cardioprotective agent, likely exerting its effects by targeting Tcap protein and upregulating its expression, thereby helping preserve cardiomyocyte structural and functional integrity.

Bazedoxifene (BAZ), a selective estrogen receptor modulator, has recently been demonstrated to inhibit the IL-6/STAT3 signaling pathway; however, its direct effects on cardiac fibroblasts and the underlying mechanisms remain unclear. Isoproterenol (ISO)-stimulated Sprague–Dawley neonatal rat cardiac fibroblasts (CFs) were employed as an in vitro model. CCK-8 assay, flow cytometry, Transwell migration assay, ELISA, qRT-PCR, and Western blot were applied to evaluate the effects of BAZ on CF activation, proliferation, migration, and collagen synthesis. Additionally, IL-6 overexpression via lentivirus (Lv-IL-6) was used to assess mediation by IL-6/STAT3 signaling. BAZ (5 μmol/L) significantly inhibited ISO-induced CF proliferation by inducing G₀/G₁ cell-cycle arrest; migration and upregulation of α-SMA and Collagen I/III were reduced; IL-6, TGF-β1, and hydroxyproline concentrations in the conditioned medium were decreased; STAT3 phosphorylation was significantly suppressed. Supplementation with Lv-IL-6 partially reversed these effects. The suppression of ISO-induced CF activation and fibrotic phenotype was associated with inhibition of IL-6 expression and blockade of IL-6/STAT3 signaling, suggesting the involvement of this pathway in the anti-fibrotic effects of BAZ. These findings provide in vitro evidence supporting BAZ as a candidate anti-myocardial fibrosis agent.