Balanophora dioica ethanol extract ameliorates isoproterenol-induced myocardial injury by suppressing fibrosis, inflammation and apoptosis by regulating TLR4/MyD88/NF-κB signaling pathway

Balanophora dioica R.Br.ex Royle, belongs to the the Balanophoraceae family, has been documented as Chinese folk medicine in Lahu nationality in China for millennia. Myocardial injury is the main manifestation of cardiovascular disease. However, the role of Balanophora dioica ethanol extract (BDEE) in improving myocardial injury is unclear. The main purpose of this study is to clarify the pharmacological effect and molecular mechanisms of BDEE on myocardial injury. The major compounds of BDEE were analyzed by GC-MS and HPLC-FTICR-MS. The male C57BL/6 mice were randomly divided into 6 groups (n = 10), the control group, the isoproterenol (ISO) model group, ISO + 100, 200, and 400 mg/kg/d of BDEE groups, and the BDEE group (400 mg/kg/d). The heart weight/body weight was calculated, serum biochemistry markers CK, LDH, and myocardial enzyme indexes MDA, SOD, CAT, GSH-Px were measured by corresponding kits. Heart tissue histopathology was detected by hematoxylin-eosin and Sirius Red staining. Immunohistochemistry and western blotting were used to determine the protein expression associated with myocardial fibrosis, inflammation and apoptosis. TUNEL staining was used to evaluate the apoptosis level. The results demonstrated that BDEE can restore cardiac morphology and serum biochemical level, and restrain ISO-induced myocardial fibrosis by regulating TGF-beta 1/ Smad3 pathway. Additionally, BDEE can reduce inflammation-related TLR4, MyD88, IRAK-1, TRAF-6, and NF-kappa B expression, and also inhibit cardiomyocyte apoptosis by regulating the expression of Bcl-2, Bax, Caspase-9 and Caspase-3. The above results indicated that BDEE improved ISO-induced myocardial injury by regulating myocardial fibrosis, inflammation and apoptosis, and it may be developed as a potential drug to prevent cardiovascular diseases.