Chlorogenic acid and ferulic acid in SMYAD alleviate diabetic cardiomyopathy by inhibiting cardiac lipotoxicity via GCGR/PPARα and GCGR/AMPK pathways

Background

Diabetic cardiomyopathy (DCM) causes a high risk of heart failure, necessitating effective therapies. The Si-Miao-Yong-An decoction (SMYAD) has been widely applied in the clinical management of diabetes mellitus and cardiovascular diseases within the paradigm of traditional Chinese medicine (TCM), but its active constituents and mechanism of the action against DCM are poorly understood.

Purpose

The aim of this study was to evaluate the effects of chlorogenic acid (CGA) and ferulic acid (FA), the main active ingredients of SMYAD, on cardiac function and cardiac lipotoxicity in mice with DCM, as well as to investigate their potential molecular mechanisms.

Methods

The cardioprotective effects of CGA and FA on DCM mice were identified by echocardiography, HE, Masson, and Oil Red O. Immunofluorescence, flow cytometry, MitoTracker Green staining, and seahorse analysis were used to study the effects of CGA and FA on palmitic acid (PA)-induced lipotoxicity in cardiomyocytes. Finally, the regulatory effects of CGA and FA on GCGR/PPARα and GCGR/AMPK signalling pathways were detected by Ad GCGR-infection, molecular docking, RT-PCR and western blot.

Results

Based on previously identified 20 representative blood prototype components and in vitro multilayer lipid toxicity analysis, chlorogenic acid (CGA) and ferulic acid (FA) were screened as the main active components of SMYAD against DCM. In vivo experiments showed that CGA and FA attenuated lipotoxicity associated with cardiac GLC/GCGR in DCM mice, thereby protecting cardiac function. In vitro results showed that GCGR inhibitor (Adomeglivant) reduces PA-induced apoptosis, indicating that PA leads to cardiomyocyte lipotoxic apoptosis by activating GCGR. Moreover, CGA and FA inhibit PA-induced cardiomyocyte lipotoxic apoptosis, mitochondrial dysfunction, and energy substrate transition through inhibiting GCGR/PPARα and GCGR/AMPK pathways. Furthermore, GLC-stimulated/GCGR-infected H9c2 cardiomyocyte lipotoxic apoptosis and downstream proteins were effectively suppressed by CGA and FA, which is consistent with the effect of Adomeglivant. Docking results showed that ASP1018 and THR1024 of GCGR are the principal molecular targets for both CGA and FA.

Conclusion

GLC lipotoxic signaling is a crucial target in mediating cardiac lipotoxicity development. CGA and FA could inhibit DCM by regulating the GCGR/PPARα and GCGR/AMPK pathway, offering a novel strategy for the development of anti-DCM drugs.