Atrium high-frequency excitation is the feature of AF. The occurrence of AF is due to triggering rapidly in a vulnerable atrial substrate caused by repetitive focal ectopic firings, while the maintenance is not only related to triggers as well as vulnerable substrate but various risk factors5–7. These non-modifiable and modifiable risk factors work together to cause inflammation, atrium remodeling, atrium fibrosis and so on2–4. Inflammasome and inflammatory signaling pathways involve in the atrial electrical change, calcium handling and structural remodeling32–33. In addition, enhancement of inflammation will exacerbate fibrosis of cardiac fibroblasts and apoptosis of cardiac myocytes34–35. It is clearly that inflammation is key pathology of AF, and anti inflammation can delay the development of AF.
Citrus medica L.var.sarcodactylis Swingle (FS), Nardostachys jatamansi DC. (GS) and Salvia miltiorrhiza Bge.(DS) are general Chinese herbal medicine treating different disease, while combination of the three herbal medicine is often an essential existing in the AF-treating decoction. Citrus medica L.var.sarcodactylis Swingle had anti-inflammatory effect36. 6-Demethoxytangeretin, Demethylnobiletin and Diosmetin, maybe important compounds treating AF, are all belong to citrus flavonoid. 6-Demethoxytangeretin can regulate inflammatory response mediated by mast cell through suppressing production and gene expression of IL637. Demethylnobiletin, also known as 5-Demethylnobiletin, has anti-inflammatory effect which can inhibit lipopolysaccharide-induced NO production and reduce inflammation-related cytokines (IL6, IL-1β, TNF-α) elevation through regulating JAK2/STAT3 pathway38–39; 5-Demethylnobiletin also can counteract the production of ROS accelerated by CCL4 and enhance the antioxidant enzymes40. Diosmetin can reduce the levels of inflammatory mediators just like 5-Demethylnobiletin41; specially, Diosmetin can exert cardioprotective effect on myocardial ischaemia injury in neonatal rats by decreasing oxidative stress and myocardial apoptosis which maybe related to AMPK signaling activation42–43. Nardostachys jatamansi DC. is a commonly used herbal medicine treating arrhythmia, which had anti-cholinesterases, anti-hyperglycemic anti-inflammatory, anti-hypertensive and anti-tyrosinase effects44; it also has antiproliferative potential and can prevent cell death of cardiomyocyte45–46. Nardoguaianone A, nardoperoxide and nardoguaianone B as potential anti AF compounds need further research. Salvia miltiorrhiza Bge., widely known in internationally, had anti-inflammation, anti-oxidation, anti-atherogenesis and anti-diabetes effects47. Study showed that tanshinol can protect human umbilical vein endothelial cells against hydrogen peroxide-induced apoptosis through enhancing antioxidant defense and preserving mitochondrial function of cells48; Sclareol can protect hearts against Ang II-induced injuries through inhibiting MAPK-mediated inflammation49; and isotanshinone can mediate neutrophil to anti inflammation50. These potential anti AF compounds play a role through intervening inflammation.
In this study, we found 87 bioactive compounds and 129 AF-related targets of C-C,N,S. Through analyzing for the 129 targets, we determined that C-C,N,S, has the anti inflammatory effect and can treating AF through controlling inflammation as well as further controlling atrial remodeling and fibrosis. The PPI network analysis indicated that TNF and IL6 were key genes, cellular response to chemical stress and response to oxidative stress were key biological processes. The relationship between IL6, TNF and AF had been validated51–52 and that pointed that the mechanism of C-C,N,S treating AF maybe related to inflammation. Then the gene specific expression analysis provided a possibilities that C-C,N,S can regulate the inflammation occurred in cardiac myocytes, adipocytes and endothelial which maybe generated by liver diseases and heart diseases53–55. Subsequently, GO function and KEGG pathways analysis further explained the anti inflammation mechanism of C-C,N,S. The main targets from target-pathway network (Fig. 7E) focused on mitogen activated protein kinase (MAPK) family. MAPK signaling pathway plays an important roles in biological processes such as cell growth, differentiation, apoptosis, and inflammation56–57. Studies showed that the activation of phosphorylated MAPK signifcantly increased the susceptibility to AF58. and AF atrial structural remodeling could be reversed by decreasing MAPK expression59. In addition, AKT1 as a key genes from PI3K-Akt signaling pathway, plays a role in the regulation of cell proliferation, survival and metabolism60–61. Studies showed that activated PI3K-Akt signaling pathway could protect the atrial myocytes from excessive oxidative stress and inflammatory processes to resist atrial remodeling62 and also could affect pulmonary fibrosis through involving in the expression of collagen and cell proliferation in lung fibroblasts63. Finally, we validated the conclusion using the gene chip sets of POAF and SR patients. C-C,N,S could indeed mediate the inflammatory-related signaling pathway to regulate inflammatory process and further alleviate atrium remodeling as well as fibrosis. As as an endogenous mediator of inflammation, TNF-α involves in atrial fibrosis64. In addition, the activation of TNF-α signaling promote atrial remodeling33. FS, GS and DS maybe down-regulate JNK1/2 to reduce the expression of inflammasome such as IL6; GS maybe also down-regulate TNF directly to inhibit activation of TNF signaling pathway (Fig. 8A). Studies have found that IL-17 signaling pathway stimulates the release of proinflammatory cytokines, which promote myocardial fibrosis and thus induce the development of AF65–66. GS and DS maybe down-regulate MAPKs to reduce the expression of inflammasome such as IL6 (Fig. 8B). In POAF patients, PI3K-Akt signaling pathway is down-regulated, which is in accordance with Zhao’s research62. FS maybe mediate AKT1 directly to affect signal transduction of downstream (Fig. 8C). These needed to further confirmed by experiments.