Network pharmacology analysis and experimental validation to explore the mechanism of Shenlian extract on myocardial ischemia

Shenlian extract (SL), extracted from Salvia miltiorrhiza Bunge and Andrographis paniculata (Burm. f.) Nees, has been proved to be effective in the prevention and treatment of atherosclerosis. Recently, we have partially elucidated the mechanisms involved in the therapeutic effects of SL on myocardial ischemia (MI). However, the underlying mechanisms remain largely unclear. This study aims to explore the potential molecular mechanism of SL on MI on the basis of network pharmacology. First, the main active ingredients of SL were screened in the Traditional Chinese Medicine Integrated Database, and the MI-associated targets were collected from the DisGeNET database. Then, we used compound–target and target–pathway networks to uncover the therapeutic mechanisms of SL. On the basis of network pharmacology analysis results, we assessed the effects of SL in MI rat model and oxygen glucose deprivation model of H9c2 cells and validated the possible molecular mechanisms of SL on myocardial injury in vivo and in vitro. The network pharmacology results showed that 37 potential targets were recognized, including TNF-α, Bcl-2, STAT3, PI3K and MMP2. These results revealed that the possible targets of SL were involved in the regulation of inflammation and apoptosis signaling pathway. Then, in vivo experiments indicated that SL significantly reduced the myocardial infarction size of MI rats. Serum CK-MB, cTnT, CK, LDH, and AST levels were significantly decreased by SL (P < 0.05 or P < 0.01). In vitro, SL significantly increased H9c2 cell viability. The levels of inflammation factors including TNF-α and MMP2 were significantly decreased by SL (P < 0.05 or P < 0.01). TUNEL and Annexin V/propidium iodide assays indicated that SL could significantly decrease the cell apoptotic rate in vivo and in vitro (P < 0.05 or P < 0.01). The remarkable upregulation of anti-apoptotic Bcl-2 and downregulation of pro-apoptotic Bax protein level further confirmed this result. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the PI3K–AKT and JAK2–STAT3 pathways were significantly enriched in SL. Compared with the model group, SL treatment significantly activated the PI3K–AKT and JAK2–STAT3 pathways in vivo and in vitro according to Western blot analyses. SL could protect the myocardium from MI injury. The underlying mechanism may be related to the reduction of inflammation and apoptosis by activating the PI3K/AKT and JAK2/STAT3 pathways.