Qishen Yiqi Dripping Pills Combined with Exosomes Alleviate Myocardial I/R Injury by Regulating Macrophage Polarization via miRNA-155-5P

INTRODUCTION: To investigate the protective mechanism of Qishen Yiqi Dropping Pills (Qishen) and its key active ingredients in combination with exosomes from bone marrow mesenchymal stem cells (BMSCs) against myocardial ischemia/reperfusion (I/R) injury. METHODS: Infarct area was assessed by Evan's Blue/TTC double staining, myocardial apoptosis was analyzed by TUNEL staining, ATP content and NAD+/NADH ratio were detected biochemically, macrophage phenotype of myocardial tissues was detected by flow cytometry, activation of the mTOR/PI3K/Akt pathway was detected by Western blotting, and miR-155-5p expression was detected by qRT-PCR. 155-5p expression. Exo were given to identify the M1/M2 phenotypic transition by immunofluorescence, and the molecular mechanism was verified as in the in vivo experiments. RESULTS: Compared with the model group, the Qishen, ginsenoside, and Exo group significantly reduced the infarcted area of the heart and promoted M2 and M2 phenotypic conversion, promoted M2- type macrophage infiltration, up-regulated the p-Akt/Akt ratio, and inhibited the expression of miR- 155-5p, but the combination therapy group did not show a synergistic effect, but the above protective effects were significantly weakened by the removal of macrophages. Ginsenoside and Exo synergistically promoted M2 polarization, activated the mTOR/PI3K/Akt pathway and upregulated miR-155-5p expression. DISCUSSION: Qishen, particularly its active component ginsenoside, synergizes with BMSC-Exo to alleviate myocardial I/R injury by modulating macrophage polarization via the miR-155- 5p/mTOR/PI3K/Akt signaling axis. CONCLUSION: Qishen synergistically regulates the miR-155-5p/mTOR/PI3K/Akt signaling axis through ginsenoside components in BMSCs exosomes, promoting macrophage polarization toward M2-type, improving myocardial energy metabolism and attenuating I/R injury, and this protective effect is macrophage-dependent.