Qishen Huoxue Granule Ameliorates LPS-induced Cardiomyocyte Injury by Suppressing Excessive Autophagy via MasR/PI3K-AKT-mTOR Pathway.

Objective: Qishen Huoxue Granule (QHG), a classical Traditional Chinese Medicine prescription, can reduce septic cardiomyopathy in the clinic. However, the mechanism of QHG remains unclear. This study aims to investigate the mechanism and effect of QHG-contained serum (QHG-CS) on sepsis-induced cardiomyopathy (SICM).

Methods: QHG was administered to Wistar rats via gavage to obtain QHG-CS. The chemical constituents of QHG-CS were identified via UPLC-Q-TOF-MS. In vitro, rat cardiomyocytes H9c2 cells isolated from embryonic BD1X rat heart tissue, and septic myocardial injury model was established by inducing H9c2 cells with lipopolysaccharide (LPS). Cell viability was assessed through CCK-8. Protein expression was determined using western blot, and gene expression was measured using real-time quantitative PCR. Cell autophagy was investigated by detecting LC3 expression using flow cytometry and immunofluorescence. In addition, three inhibitors, A779 (MasR), wortmannin (PI3K) and rapamycin (mTOR) were used to focus the potential therapeutic targets.

Results: QHG-CS significantly improved the survival of septic cardiomyocytes (p<0.0001). The expression of autophagy-related markers Beclin1, ATG5, and LC3II/I was increased in LPSinduced cardiomyocytes, which could be inhibited by QHG-CS. QHG-CS upregulated the mRNA expression of MasR, PI3K, and AKT, as well as the phosphorylation of PI3K, AKT, and mTOR. Moreover, A779 markedly lowered mRNA levels of MasR, PI3K, and mTOR, while wortmannin decreased mRNA levels of PI3K and mTOR, whereas rapamycin only suppressed mTOR phosphorylation.

Conclusions: By inhibiting excessive autophagy through upregulation of the MasR/PI3K-AKTmTOR pathway, QHG can alleviate sepsis-induced cardiomyocyte damage. This study provides novel perspectives for the management of sepsis-induced cardiac damage.