Total flavonoids of Dracocephalum heterophyllum Benth protects against coronary microvascular dysfunction by...

Coronary microvascular dysfunction (CMD) is a high-risk factor for many cardiovascular events and lacks targeted therapeutic strategies. Dracocephalum heterophyllum Benth (DHB), a traditional herb used in Tibetan and Uighur medicine, is used for managing hypertension-realted conditions. Modern pharmacological studies have confirmed flavonoids as the primary bioactive components of DHB. However, its potential effect on CMD remain unclear. This study aimed to investigate the impact of DHBF (flavonoids of DHB) on hypertension-induced CMD and myocardial damage, as well as the underlying molecular mechanisms. The serum-absorbable components of DHBF were identified via UPLC-Q-TOF-MS. Network pharmacology was employed to predict DHBF's bioactive components and therapeutic pathways in hypertension, CMD, and myocardial injury. A spontaneously hypertensive rat (SHR) model was used to evaluate DHBF's effects, validated by echocardiography, histopathological analysis, and molecular assays, including HE staining, Masson staining, ELISA, and qRT-PCR. Proteomic analysis, Immunofluorescence and Western blot were used to explore the mechanisms. A total of 18 serum-absorbable components of DHBF were identified. Network pharmacology analysis highlighted apoptosis and apoptosis-related pathways as key contributors to DHBF's protective effects against hypertension, CMD and myocardial damage. In SHR models, DHBF treatment was associated with improved CMD symptoms and cardiac function, as validated by myocardial contrast echocardiography (MCE), transthoracic echocardiography, and hemodynamic measurements (P < 0.05). Histopathological evaluation revealed that DHBF-treated rats exhibited reduced myocardial pathological damage and decreased collagen fiber deposition in cardiac tissues (P < 0.05). Serum biomarker analyses showed dose-dependent increases in ANP and BNP levels, accompanied by decreases in LDH and CK concentrations (P < 0.05). Furthermore, DHBF-treated rats displayed attenuated oxidative stress injury and reduced inflammatory cytokines levels (P < 0.05). Proteomic analysis indicated that differentially expressed proteins following DHBF treatment were primarily enriched in apoptosis-related pathways. Mechanistically, DHBF treatment was associated with the reulation of P-STAT3/STAT3 signaling pathway, leading to decreased cardiomyocyte apoptosis, pyroptosis, and necroptosis. This was evidenced by altered expression of Bax, Caspase 3, Bcl2, caspase 1, cleaved caspase 1, NLRP3, ASC, GSDMD, and MLKL, as well as changes in the Bcl2/Bax ratio (P < 0.05). DHBF may represent a promising candidate for hypertension-related cardiovascular complications, via dual regulation of microvascular function and cardiomyocyte survival.