Abstract:Objective To investigate the effect of Danggui Buxue Decoction on myocardial injury and its mechanism of action in a rat model of myocardial infarction. Methods Rats were randomly divided into sham-operation group, model group, low- and high-dose Danggui Buxue Decoction groups, and diltiazem group. Ligation of the left anterior descending coronary artery was performed to establish a rat model of myocardial infarction after administration for 7 consecutive days. After 24 hours of ischemia, TTC staining was used to measure myocardial infarct area; HE staining was used to observe the histomorphology of myocardium; the microplate method was used to measure the content of lactate dehydrogenase(LDH);ELISA was used to measure the content of creatine kinase-MB (CK-MB); Western blot was used to measure the expression levels of phosphorylated phosphatidylinositol 3-kinase (p-PI3K), phosphorylated protein kinase B (p-AKT), phosphorylated mammalian target of rapamycin (p-mTOR), and the autophagy-related proteins LC3Ⅱ/Ⅰ, Beclin-1, and p62. Results Danggui Buxue Decoction significantly reduced myocardial infarct area (P<0.05), reduced the serum levels of CK-MB and LDH (P<0.05), and alleviated the pathological injury of myocardial tissue, suggesting that Danggui Buxue Decoction had a marked protective effect against myocardial infarction. Western blot showed that Danggui Buxue Decoction significantly reduced the expression levels of the autophagy pathway-related proteins p-PI3K, p-AKT, and p-mTOR (P<0.05), increased the expression levels of the autophagy-related proteins LC3Ⅱ/Ⅰ and Beclin-1(P<0.05), and reduced the expression level of p62 (P<0.05). Conclusion Danggui Buxue Decoction may improve myocardial injury in the rat model of myocardial infarction by inhibiting the PI3K/AKT/mTOR signaling pathway and activating autophagy.