Optimized New Shengmai Powder suppresses ferroptosis in ischemic cardiomyocytes via cGMP-PKG signalling.

backgroundShengmai Powder is a classic Traditional Chinese Medicine formula that has been used for centuries to manage cardiovascular diseases characterized by "Qi-Yin deficiency with blood stasis." Optimized New Shengmai Powder (ONSMP), a modern refinement of this formula, has shown clinical efficacy in improving cardiac function in patients with ischemic heart failure. Although our previous studies have demonstrated pronounced cardioprotective effects of ONSMP in preclinical models, the underlying molecular mechanisms-particularly those regulating cardiomyocyte death-remain incompletely understood at the cellular level. Clarifying these mechanisms is essential to bridge traditional therapeutic practice with contemporary scientific validation and to substantiate the clinical utility of ONSMP with modern mechanistic evidence. PURPOSE: This study elucidates the molecular mechanisms by which ONSMP inhibits ferroptosis in cardiomyocytes.

methodsLC-MS/MS was used to identify active constituents absorbed into the systemic circulation following ONSMP administration in a rat model of ischemic heart failure. A network pharmacology approach was then applied to predict potential therapeutic targets and signaling pathways through which ONSMP may treat ischemic heart failure and inhibit cardiomyocyte ferroptosis, followed by molecular docking and molecular dynamics simulations to evaluate the binding stability between representative compounds and core targets. An oxygen-glucose deprivation (OGD) injury model was established in H9C2 cardiomyocytes to mimic the pathological microenvironment of ischemic heart failure, and cells were treated with ONSMP-containing serum in the presence or absence of core-target inhibitors. Cell viability, iron homeostasis, lipid peroxidation, mitochondrial morphology and function, and the expression of ferroptosis-related genes and proteins were assessed. Finally, the functional contributions of key active constituents to the amelioration of ischemic myocardial injury were further validated.

resultsA total of 44 absorbed constituents of ONSMP were detected in rat serum. Network pharmacology analysis indicated that ONSMP targets were significantly enriched in pathways related to oxidative stress responses and lipid peroxidation, with the cGMP-PKG signaling pathway emerging as a central hub. Molecular simulations confirmed stable interactions among AKT1, eNOS, PKG1, STAT3, and GPX4. In OGD-injured H9C2 cardiomyocytes, ONSMP-containing serum significantly improved cell viability, reduced intracellular iron accumulation and malondialdehyde levels, preserved mitochondrial integrity, and upregulated GPX4 expression. These effects were associated with activation of the AKT1/cGMP-PKG axis and were partially abrogated by AKT1 inhibition. Baicalin and Kaempferide were identified as representative bioactive constituents that may contribute to these anti-ferroptotic effects.

conclusionONSMP exerts cardioprotective effects through multiple constituents acting on multiple targets. These effects are mediated, at least in part, by modulation of the cGMP-PKG signaling pathway, which enhances antioxidant defenses and suppresses ferroptosis in cardiomyocytes. Active constituents such as Baicalin and Kaempferide together provide a modern biological basis for the traditional therapeutic efficacy of ONSMP in ischemic heart failure.