CAD is called "heart tingling" in Mongolian medicine. It is due to the dysfunction of the "three roots" and "seven elements", which hinders the movement of Heyi and the blood. The three roots refer to Heyi Xila and Badagan. Seven elements refer to dietary essence, blood, muscle, fat, bone, bone marrow and semen. Combining modern Western medicine theories, Mongolian medicine currently divides CAD into Heyi heart tingling, bloody heart tingling, adhesive heart tingling and Huyang heart tingling. Mongolian medicine mainly treats CAD by promoting the differentiation of turbidity and improving Heyi and blood circulation. BLEC is a prescription confirmed by famous Mongolian medicine experts repeatedly based on the above-mentioned etiology and pathogenesis and combined with Mongolian medicine theory and clinical practice experience. It can treat CAD by adjusting functions of the body's three root and seven element .
To the best of our knowledge, this is the first study integrating network pharmacology and molecular docking analyses to reveal the pharmacological mechanisms of BLEC for treating CAD. We identified a total of 228 active compounds in BLEC. Furthermore, a total of 80 potential target genes related to the action of BLEC on CAD were identified. PPI analysis revealed that the top-ranking genes, AKT Serine/Threonine Kinase 1 (AKT1), Epidermal Growth Factor Receptor (EGFR), Proto-oncogene c-Fos (FOS), Mitogen-activated protein kinase 1 (MAPK1), Mitogen-activated protein kinase 14 (MAPK14), Signal transducer and activator of transcription 3 (STAT3), Cellular tumor antigen p53 (TP53) and Vascular endothelial growth factor A (VEGFA), may be the crucial targets for BLEC treating CAD. Functional enrichment analysis revealed the over-represented GO terms and their functional domains. KEGG pathway enrichment analysis revealed that the 80 target proteins were significantly enriched in 162 related signal pathways. Among them, fluid shear stress and atherosclerosis appeared to be the most critical pathways involved in the treatment of CAD. Furthermore, molecular docking analysis demonstrated that the representative compounds could bind to the target protein binding site.
In this study, systematic pharmacological method is applied to forecast and explain the molecular mechanisms of BLEC on CAD. In BLEC’s active components-targets network, we get 81 targets affected by 144 bioactive compounds. The 10 top-ranking compounds including quercetin, luteolin, kaempferol, naringin, tanshinone IIA, beta-carotene, 7-O-methylisomucronulatol, piperine, isorhamnetin, Xyloidone are identified as BLEC’s active ingredients. Their biological activities against CAD were mentioned above. Quercetin is a natural bioflavonoid found in vegetables and fruits including onions, grapes, tea, apples, and red wine. It can improve endothelial cell function[18–20], inhibit dendritic cell activation, inhibit foam cell formation by inhibiting oxidized low-density lipoprotein-induced apoptosis of macrophages and regulates cholesterol metabolism and lipoprotein metabolism by regulating cholesterol metabolism-related gene expression[23–25]. Luteolin, is a natural flavone which is abundant in edible plants, including green chilies, broccoli, French beans, onion leaf, white radish, carrots, ragweed pollen and clover blossom. Studies have shown that it can inhibit the occurrence of atherosclerosis by inhibiting macrophage inflammation[27, 28]. Kaempferol, is a common natural yellow flavonoid with a low molecular weight, which exists in a number of traditional Chinese medicine and plant derived foods. Kaempferol and its glycosides have many pharmacological functions, for example, they can serve as anti-inflammatory, antioxidant, and anticancer, antidiabetic, neuroprotective, analgesic, antimicrobial, and anti-allergic drugs. Studies have shown that kaempferol conducts anti-atherosclerotic effect by regulating the expression of gene and protein in inflammatory molecules. Naringin is the bitter component in a kind of grapefruit which is often found in its flowering parts, peels, juice and vegetative parts. Naringin can improve blood lipid levels, metabolic imbalances, and inhibit inflammatory reactions, and inhibit atherosclerosis. Tanshinone IIA is a main bioactive component isolated from the roots of the Chinese herb Salviae miltiorrhiza Bunge (Danshen), can regulate the autophagy and polarization of macrophages, and even the expression of non-coding RNA related to atherosclerosis and inflammation, antioxidant, improve endothelial cell function, and regulate cholesterol metabolism-related pathways affect cholesterol metabolism[41, 42]. Epidemiological evidence suggests that beta-carotene helps decrease the risk for atherosclerosis by protecting LDL from oxidation[43, 44]. Isorhamnetin, a bioactive compound, exists in herbal plants, and possesses multiple biological properties. It can inhibit macrophage apoptosis and inhibit atherosclerosis.
According to PPI core network analysis and molecular docking results, it is shown that the main components of BLEC can prevent and treat CAD by affecting CAD-related top-ranking genes AKT1, EGFR, FOS, MAPK1, MAPK14, STAT3, TP53 and VEGFA. A large number of studies have confirmed that intervention of the above key genes can achieve the effect of preventing and treating atherosclerosis. The lack of AKT1 can promote the release of pro-inflammatory factors, and enhance the apoptosis of endothelial cells and macrophages, leading to the development of atherosclerosis. The expression of FOS in monocytes in the blood of patients with CAD is significantly increased, and its expression level is related to the severity of atherosclerosis. Inhibiting the expression of FOS of THP-1 cells can reduce the release of inflammatory factors. The activation of STAT3 can promote the occurrence of atherosclerosis by affecting endothelial cell dysfunction, macrophage polarization, inflammation, and immunity. Inhibition of STAT3 can achieve the effect of inhibiting atherosclerosis. P53 is a classic tumor suppressor gene. Inhibition of P53 can significantly increase the proportion of cell proliferation and apoptosis, and promote the occurrence of atherosclerosis. The MAPK pathway is a classic inflammatory pathway. Inhibiting MAPK can reduce the release of macrophages MCP-1, inhibit the infiltration of macrophages into the plaque, and inhibit the occurrence and development of atherosclerosis. The expression of EGFR and its ligands on arterial plaques of patients with CAD is significantly increased. By inhibiting EGFR, the uptake and inflammatory release of lipids by macrophages can be restricted, thereby inhibiting the occurrence and development of atherosclerosis. VEGFA plays an important role in the formation of blood vessels, and can induce apolipoprotein to change in the direction of pro-inflammatory, and its expression increases in atherosclerosis model mice. Inhibiting the expression of VEGFA in vascular smooth muscle can reduce the size of atherosclerotic plaques.
However, the study also has its limitations. On the one hand, we ignored the actual dosage and performance of traditional Mongolian medicine, which can be significant in research. Besides, network pharmacology is based on the data in the existing literature. The prediction is limited.
In this pharmacology network–based study, active ingredients, core targets, and key signal pathways of BLEC in treating CAD are systematically investigated. It also provides potential therapeutic mechanisms for further researches. However, intensive explorations are required to explain the in-depth mechanisms of the active compounds, which may give guidance to the development of novel broad-spectrum antiviral agents.