Acupuncture at Danzhong Suppresses Myocardial Ischemic Injury by Reducing Mitochondrial Damage

Objective: This study investigated whether acupuncture at Danzhong can treat ischemic heart disease. Materials and Methods: A rat model of ischemic heart disease was established through the subcutaneous injection of isoproterenol hydrochloride (ISO), followed by acupuncture at Danzhong for 3 weeks. Markers of myocardial injury (lactate dehydrogenase and creatine kinase) were measured to evaluate myocardial cell damage using enzyme-linked immunosorbent assay kits. 2,3,5-triphenyltetrazolium chloride staining is used to detect the myocardial infarct size. Hematoxylin and eosin staining Masson was used to detect myocardial tissue damage. The mitochondrial oxidative damage in myocardial cells was evaluated by detecting levels of nicotinamide adenine dinucleotide phosphate oxidase, nicotinamide adenine dinucleotide oxidase, cytochrome c oxidase, and citrate synthase in the myocardial tissue. Protein levels of PGC1α , Nrf1 , and mtTFA were measured through western blotting. Liquid chromatograph–mass spectrometer (LC-MS/MS) and nuclear magnetic resonance spectroscopy were used to analyze the serum metabolomics. Results: Results showed that after subcutaneous injection of ISO, rats exhibited ischemic heart disease, which manifested as cardiac dysfunction, increased myocardial enzyme release, myocardial infarction, myocardial necrosis, and mitochondrial damage. Acupuncture at Danzhong can effectively treat ISO-induced ischemic heart disease, reducing cardiac dysfunction and myocardial enzyme release and alleviating myocardial infarction necrosis and mitochondrial damage. To further investigate the possible mechanism of acupuncture in Danzhong for the treatment of induced ischemic heart disease, we conducted metabolomics analysis on the experimental groups. Results show that acupuncture at Danzhong had a significant effect on propylene glycol, carnitine, lactate, acetone, 2-hydroxyisovalerate, proline, N, N-dimethylformamide, 3-hydroxybutyrate, and acetoacetate. MetaboAnalyst 5.0 analysis of differentially abundant metabolites revealed that these differentially abundant metabolites were enriched mainly in aminoacyl-tRNA biosynthesis, the citrate cycle (tricarboxylic acid [TCA] cycle), valine, leucine and isoleucine biosynthesis, and butanoate metabolism. The TCA cycle plays an important role in ischemic heart disease, and in this study, we found that subcutaneous injection of ISO resulted in mitochondrial damage in rat cardiomyocytes and obstructed the TCA cycle. Acupuncture at Danzhong can significantly reduce mitochondrial damage and ameliorate mitochondrial obstruction. Conclusions: These results suggest that acupuncture at Danzhong can effectively treat ischemic heart disease, and the mechanism of action may alleviate myocardial cell damage by improving TCA circulation obstruction.