Mechanism of paeonol combined with paeoniflorin against myocardial ischemia injury:based on proteomics / 中国中药杂志

The study aims to investigate the effect of the compatibility of paeonol and paeoniflorin(hereinafter referred to as the compatibility) on the expression of myocardial proteins in rats with myocardial ischemia injury and explore the underlying mechanism of the compatibility against myocardial ischemia injury. First, the acute myocardial infarction rat model was established by ligation of the anterior descending branch of the left coronary artery. The model rats were given(ig) paeonol and paeoniflorin. Then protein samples were collected from rat cardiac tissue and quantified by tandem mass tags(TMT) to explore the differential proteins after drug intervention. The experimental results showed that differential proteins mainly involved phagocytosis engulfment, extracellular space, and antigen binding, as well as Kyoto encyclopedia of genes and genomes(KEGG) pathways of complement and coagulation cascades, syste-mic lupus erythematosus, and ribosome. In this study, the target proteins and related signaling pathways identified by differential proteomics may be the biological basis of the compatibility against myocardial ischemia injury in rats.

Molecular mechanism of luteolin regulating lipoxygenase pathway against oxygen-glucose deprivation/reperfusion injury in H9c2 cardiomyocytes based on molecular docking / 中国中药杂志

The aim of this study was to investigate the mechanism of luteolin regulating lipoxygenase pathway against oxygen-glucose deprivation/reperfusion(OGD/R) injury in H9 c2 cardiomyocytes. First, Discovery Studio 2019 was used for the molecular docking of luteolin with three key enzymes including lipoxygenase 5(ALOX5), lipoxygenase 12(ALOX12), and lipoxygenase 15(ALOX15) in lipoxygenase pathway. The docking results showed that luteolin had high docking score and similar functional groups with the original ligand. From this, H9 c2 cardiomyocytes were cultured in vitro, and then the injury model of H9 c2 cardiomyocytes was induced by deprivation of oxygen-glucose for 8 h, and rehabilitation of oxygen-glucose for 12 h. Cell viability was detected by tetrazolium(MTT) colorimetry. H9 c2 cardiomyocytes were observed with a fluorescence inverted microscope, and colorimetry was used to detect the level of lactate dehydrogenase(LDH) in cell supernatant. The results showed that luteolin could significantly protect the morphology of H9 c2 cells, significantly improve the survival rate of H9 c2 cardiomyocytes in OGD/R injury model, reduce the level of LDH in cell supernatant, inhibit cytotoxicity, and maintain the integrity of cell membrane. The inflammatory cytokines interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) were detected by enzyme-linked immunosorbent assay. Compared with the model group, luteolin can significantly reduce the release of IL-6 and TNF-α. Western blot was employed to detect the protein levels of ALOX5, ALOX12, and ALOX15 in lipoxygenase pathway. After luteolin intervention, the protein levels of ALOX5, ALOX12, and ALOX15 were significantly down-regulated compared with those in model group. These results indicate that luteolin can inhibit the release of IL-6 and TNF-α by restraining the activation of lipoxygenase pathway, thereby playing a protective role in the cardiomyocyte injury model induced by OGD/R.

Effects of electroacupuncture on sympathetic nerve-related substance in myocardial tissue in mice with myocardial ischemia / 中国针灸

OBJECTIVE@#To observe the effects of electroacupuncture (EA) on sympathetic nerve-related substance in myocardial tissue in mice with myocardial ischemia (MI), and to explore its possible mechanism.@*METHODS@#Thirty adult male C57BL/6 mice were randomly divided into a sham operation group, a model group and an EA group, 10 mice in each one. The model of MI was established in the model group and EA group by ligating the left anterior descending branch of coronary artery. The mice in the sham operation group were not treated with ligating at left anterior descending branch of coronary artery, but the remaining procedure was similar with the model group. The mice in the EA group were treated with EA at "Neiguan" (PC 6) with 2 Hz/100 Hz of frequency and 2 mA of intensity, 20 min per treatment, once a day for totally 5 days. No EA was given for model group and sham operation group. The electrocardiogram was recorded and △ST value was calculated to evaluate the model. TTC staining was applied to evaluate the infarct size. Immunohistochemical (IHC) method was applied to evaluate the positive nerve fiber density in myocardial tissue. Western blot method was applied to test the protein expression levels of neuregulin-1 (NRG-1), tyrosine hydroxylase (TH), growth associated protein-43 (GAP-43).@*RESULTS@#The electrocardiogram (lead II) results indicated compared with the sham operation group, the S-T segments in the model group and EA group were increased obviously (both <0.01), indicating the MI model was established successfully. The TTC staining results indicated compared with sham operation group, the infarction size was significantly increased in the model group (<0.01); compared with the model group, the infarction size in the EA group was significantly reduced (<0.01). The IHC results indicated compared with the sham operation group, the positive nerve fiber density in myocardial was increased in the model group (<0.01); compared with the model group, the positive nerve fiber density in myocardial was reduced in the EA group (<0.05). The Western blot results indicated compared with the sham operation group, the expression levels of TH, NRG-1 and GAP-43 were significantly increased in the model group (<0.01); compared with the model group, the expression level of TH and GAP-43 were significantly reduced (<0.01) and that of NRG-1 was increased in the EA group (<0.05).@*CONCLUSION@#EA could increase the expression of NRG-1 and reduce the expression of TH and GAP-43 in myocardial tissues in MI mice, which could suppress sympathetic nerve hyperexcitability after infarction to achieve myocardial protection effect.

Prevention effect of Ligusticum chuanxiong extraction against oxidative stress injury induced by myocardial ischemia through activation of Nrf2 signaling pathway / 中国中药杂志

Ligusticum chuanxiong is one of the common traditional Chinese medicinal herbs for treating various cardiovascular and cerebrovascular diseases, and a number of previous studies have demonstrated that the extract of L. chuanxiong has strong antioxidative activity. This paper was mainly aimed to investigate the effects and possible mechanisms of L. chuanxiong extraction on oxidative stress induced by myocardial ischemia injury in rats. The rats were subcutaneously injected with isoprenaline hydrochloride to induce myocardial ischemia injury and treated for 2 weeks. Then the cardiac indexes of the rats were recorded. The concentration of malondialdehyde (MDA) and activities of serum creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were measured by colorimetry. Light microscope was used to observe the morphological changes of myocardium, and the protein expressions of nuclear factor E2 related factor 2 (Nrf2), quinone oxidoreductase (NQO1) and hemeoxygenase-1 (HO-1) in cardiac tissue were evaluated by Western blot. The results showed that L. chuanxiong extraction could decrease cardiac indexes and the values of CK, LDH and AST in blood serum, increase activities of serum SOD and T-AOC, reduce serum MDA concentration, improve myocardium structure after ischemia injury, and up-regulate the protein expressions of Nrf2, NQO1 and HO-1 in cardiac tissue. These findings revealed that the cardioprotective effects of L. chuanxiong extraction may be related to inhibiting oxidative stress through the activation of Nrf2 signaling pathway.

Application of tissue spontaneous fluorescence in myocardial ischemia injury of rats / 中国药理学通报

Aim Todiscusstheapplicationoftissue spontaneous fluorescence in myocardial ischemia injury of rats based on specific fluorescence detection technol-ogy.Methods Thechangeofspontaneousfluores-cence was compared between the myocardial tissue of normal rats and those of rats with myocardial ischemia injury and an quantitative analysis was then made.Re-sult Theresultsshowedthatspontaneousfluorescence of myocardial tissue for myocardial ischemia injury changed significantly.Spontaneous fluorescence signal of injury considerably was enhanced.The fluorescence signal which was quantified by FX Pro had statistical significance compared with normal myocardial tissue,P<0.01orP<0.05.Conclusion Ourresearchshows that spontaneous fluorescence of myocardial tissue can be enhanced obviously after myocardial ischemia inju-ry.Our research provides a method for the research and evaluation of myocardial ischemia injury model in rats which can be used in positioning,qualitative and quan-titative comparative study and in pathological,physio-logical,pharmacological and mechanism study.