BACKGROUND: Pathological cardiac hypertrophy plays a significant role in the development of heart failure, involving mitochondrial dysfunction and metabolic dysregulation. Paeoniflorin (PF) is a monoterpene glycoside derived from Paeonia lactiflora. It has demonstrated cardioprotective potential, although its precise mechanisms are still unclear.
PURPOSE: This study aimed to investigate the therapeutic effect of PF on cardiac hypertrophy induced by isoproterenol (ISO) and to uncover the underlying mechanisms, focusing on AMPK/Parkin/ACSL4-mediated mitophagy and ferroptosis.
METHODS: A mouse model of cardiac hypertrophy was established using subcutaneous ISO injections. PF was administered at low, medium, and high doses, and Fosinopril (FOS) was used as a positive control. Cardiac function and morphology were evaluated using echocardiography, hemodynamic measurements, and histological staining. In vitro validation was performed in ISO-treated H9c2 cardiomyocytes. Western blotting, PCR, mitochondrial isolation, immunofluorescence, and targeted lipidomics were employed to assess molecular changes. Pharmacological inhibition of AMPK using Compound C and siRNA targeting Parkin was used to confirm the specificity of the AMPK/Parkin pathway involvement.
RESULTS: PF significantly attenuated ISO-induced cardiac hypertrophy and improved cardiac function in vivo by activating AMPK and promoting Parkin-dependent mitophagy. PF also reduced mitochondrial accumulation of ACSL4, thereby limiting ferroptotic injury. Targeted lipidomics identified seven PF-responsive metabolites linked to lipid peroxidation, while parallel analyses demonstrated coordinated modulation of key pathway proteins involved in mitophagy and ferroptosis. Pharmacological inhibition of AMPK or knockdown of Parkin abolished these protective actions of PF. Moreover, PF decreased mitochondrial ROS generation and iron overload, further supporting its regulatory role in ferroptosis signaling.
CONCLUSION: PF attenuates ISO-induced cardiac hypertrophy by stimulating AMPK-dependent mitophagy and suppressing ferroptosis through the Parkin/ACSL4 pathway. These findings elucidate the molecular basis of PF's cardioprotective function and support its prospective application in addressing abnormal heart remodeling.
