Anti-Inflammatory Mechanisms of Total Flavonoids from Mosla scabra against Influenza A Virus-Induced Pneumonia by Integrating Network Pharmacology and Experimental Verification

Abstract

Influenza virus is one of the most common infectious pathogens that could cause high morbidity and mortality in humans. However, the occurrence of drug resistance and serious complications extremely complicated the clinic therapy. Mosla scabra is a natural medicinal plant used for treating various lung and gastrointestinal diseases, including viral infection, cough, chronic obstructive pulmonary disease, acute gastroenteritis, and diarrhoea. But the therapeutic effects of this herbal medicine had not been expounded clearly. In this study, a network pharmacology approach was employed to investigate the protective mechanism of total flavonoids from M. scabra (MSTF) against influenza A virus- (IAV-) induced acute lung damage and inflammation. The active compounds of MSTF were analyzed by LC-MS/MS and then evaluated according to their oral bioavailability and drug-likeness index. The potential targets of each active compound in MSTF were identified by using PharmMapper Server, whereas the potential genes involved in IAV infection were obtained from GeneGards. The results showed that luteoloside, apigenin, kaempherol, luteolin, mosloflavone I, and mosloflavone II were the main bioactive compounds found in MSTF. Primarily, 23 genes were identified as the targets of those five active compounds, which contributed to the inactivation of chemical carcinogenesis ROS, lipid and atherosclerosis, MAPK signaling pathway, pathways in cancer, PI3K-AKT signaling pathway, proteoglycans in cancer, and viral carcinogenesis. Finally, the animal experiments validated that MSTF improved IAV-induced acute lung inflammation via inhibiting MAPK, PI3K-AKT, and oxidant stress pathways. Therefore, our study demonstrated the potential inhibition of MSTF on viral pneumonia in mice and provided a strategy to characterize the molecular mechanism of traditional Chinese medicine by a combinative method using network pharmacology and experimental validation.

Figure 1

The HPLC chromatographic profiles of total flavonoids from Mosla scabra. The one-to-six peaks were mapped to the flavonoids as shown in Table 1.

Figure 2

Effects of MSTF on IAV-induced lung inflammation. (a) Histopathological changes of lung tissues of each group, (b) inhibition of MSTF on lung indexes, (c) histopathological scores, (d) viral loads, and (e) serum levels of proinflammatory cytokines (TNF-α, IL-6, and IL-18) in IVA-infected mice. All data were shown as mean ± SEM (n = 10). Different letters meant significant differences (P < 0.05) by Tukey's test.

Figure 3

The target profiles of MSTF on IAV-induced lung inflammation. (a) Venn diagrams showed the overlap between influenza-related genes derived from GeneCards and MSTF targets predicted by PharmMapper Server. (b) Interactions among 23 overlapped targets of MSTF. The edges indicate both functional and physical protein associations; line thickness indicates the strength of data support.

Figure 4

Identification and enrichment analysis of 23 targets of main flavonoids in MSTF. (a) The GO enrichment analysis of MSTF targets in treating IAV-induced lung inflammation. The x-axis was the enrichment degree, and the y-axis was the functional classification (i.e., biological process, cell components, and molecular function). (b) Sankey diagram showed relationships among five flavonoids, targets, and pathways. The curve thickness indicates the contribution to the regulation on the corresponding pathways.

Figure 5

Effects of MSTF on the expressions of core targets in lung tissues of IAV-infected mice. (a) Representative results of protein blots. (b) Semiquantitative analysis of those core protein expressions. All data were shown as mean ± SEM (n = 5). Different letters meant significant differences (P < 0.05) by Tukey's test.