ObjectiveTo investigate the effects of Linggui Zhugantang on mitochondrial fission and fusion and silencing information regulator 3（Sirt3）/adenosine monophosphate dependent protein kinase （AMPK） signaling pathway in chronic heart failure （CHF） rats after myocardial infarction （MI）. MethodSD rats randomly divide into sham operation group （normal saline ，thread only without ligature）， model group （normal saline， ligation of the left anterior descending coronary artery proximal to the heart）， Linggui Zhugantang group （4.8 g·kg^-1） and Captopril group （0.002 57 g·kg^-1）， with 10 rats in each group. Administere drug continuously for 28 days. Echocardiography detected cardiac function parameters. Hematoxylin eosin （HE） staining observed the pathological changes of the heart. Immunofluorescence detected the levels of reactive oxygen species （ROS）. JC-1 detect mitochondrial membrane potential. Colorimetry measure adenosine triphosphate （ATP）， superoxide dismutase （SOD）， malondialdehyde （MDA）， mitochondrial respiratory chain complex activity （Ⅰ-Ⅳ）. TdT-mediated dUTP nick end labeling （TUNEL） staining detected the apoptosis rate of myocardial tissue. Western blot detected protein expression levels of Sirt3， phosphorylated AMPK （p-AMPK）， phosphorylated dynamic-related protein 1（p-Drp1）， mitochondrial fission protein 1（Fis1）， mitochondrial fission factor （MFF）， optic atrophy protein 1（OPA1）. ResultCompared to the sham group， the left ventricular end diastolic diameter （LVIDd） and left ventricular end systolic diameter （LVIDs） were significantly increased in model group （P<0.01）， while the left ventricular short axis shortening rate （LVFS） and left ventricular ejection fraction （LVEF） were significantly decreased （P<0.01）. There were inflammatory cell infiltration and obvious pathological injury in myocardial tissue. ROS， MDA levels and myocardial cell apoptosis rate were significantly increased （P<0.01）， SOD level， ATP content， and membrane potential were significantly decreased （P<0.01）. The activity of mitochondrial respiratory chain complexes （Ⅰ-Ⅳ） was significantly decreased （P<0.01）. Levels of p-Drp1， Fis1， MFF proteins were significantly up-regulated （P<0.01）， while Sirt3， p-AMPK， OPA1 proteins level were significantly down-regulated （P<0.01）. Compared with model group， LVIDd and LVIDs were significantly decreased （P<0.01）， LVEF and LVFS were significantly increased （P<0.01）. Inflammatory cell infiltration and pathological damage of myocardial tissue were significantly relieved. ROS， MDA levels and myocardial cell apoptosis rate were significantly decreased in Linggui Zhugantang group and Captopril group （P<0.01）， SOD level， ATP content， and membrane potential significantly increased （P<0.01）. The activity of mitochondrial respiratory chain complexes （Ⅰ-Ⅳ） increased significantly （P<0.01），and p-Drp1， Fis1， MFF protein levels were significantly down-regulated （P<0.01）， Sirt3， p-AMPK， OPA1 protein were significantly up-regulated （P<0.01）. ConclusionLinggui Zhugantang can alleviate oxidative stress and apoptosis damage of myocardial cells， maintain mitochondrial function stability， and its effect may be related to mitochondrial mitosis fusion and Sirt3/AMPK signaling pathway.

ObjectiveTo investigate the protective effect of Linggui Zhugantang （LGZGT）-medicated serum against H₂O₂-induced injury in H9c2 cells and its relationship with the phosphatidylinositol 3- kinase/protein kinase B （PI3K/Akt） signaling pathway. MethodThe LGZGT-medicated serum and blank serum were prepared based on serum pharmacology. H9c2 cells were cultured in vitro and divided into a normal group， an H₂O₂ group， a 20% blank serum group， and a 20% LGZGT-medicated serum group. The cells were treated with corresponding drugs for 12 h and cultured with 100 μmol·L^-1 H₂O₂ for another 6 h. The effect of 20% LGZGT-medicated serum on the proliferation activity of H9c2 cells induced by H₂O₂ was detected by cell counting kit-8 （CCK-8） assay. Mitochondrial reactive oxygen species （ROS） level was detected by the fluorescence probe. The levels of malondialdehyde （MDA）， lactate dehydrogenase （LDH）， catalase （CAT）， and glutathione peroxidase （GSH-Px） were detected by colorimetry. Western blot was used to detect the protein expression levels of phosphoinositide 3-kinase （PI3K）， phosphorylated-PI3K （p-PI3K）， protein kinase B （Akt）， and phosphorylated-Akt （p-Akt）. Real-time fluorescence-based quantitative polymerase chain reaction （Real-time PCR） was used to detect mRNA expression of PI3K and Akt. Flow cytometry was used to detect the apoptosis rate. After the addition of PI3K inhibitor LY294002， the levels of mitochondrial ROS， LDH， and GSH-Px， protein expression of PI3K， p-PI3K， Akt， and p-Akt， and cell apoptosis rate were detected. ResultCompared with the normal group， the H₂O₂ group showed blunted cell viability （P<0.01）， increased levels of mitochondrial ROS， MDA， and LDH （P<0.01）， decreased levels of CAT and GSH-Px （P<0.01）， reduced phosphorylation and mRNA expression of PI3K and Akt （P<0.05， P<0.01）， and increased apoptosis rate （P<0.01）. Compared with the H₂O₂ group， the 20% LGZGT-medicated serum group showed potentiated cell viability， reduced levels of mitochondrial ROS， MDA， and LDH （P<0.01）， increased levels of CAT and GSH-Px （P<0.01）， up-regulated phosphorylation and mRNA expression of PI3K and Akt （P<0.05， P<0.01）， and decreased apoptosis rate （P<0.01）. The combined use of LGZGT-medicated serum and inhibitor LY294002 reversed the above-mentioned effects of LGZGT-medicated serum on H9c2 cells （P<0.05， P<0.01）. ConclusionThe protective effect of LGZGT-medicated serum on H₂O₂-induced H9c2 cell injury may be related to the regulation of the PI3K/Akt signaling pathway to reduce oxidative stress and apoptosis.