Antiviral Activity of Isoimperatorin Against Influenza A Virus in vitro and its Inhibition of Neuraminidase

Abstract

Influenza A virus (IAV) poses a severe threat to human health and is a major public health problem worldwide. As global anti-influenza virus drug resistance has increased significantly, there is an urgent need to develop new antiviral drugs, especially drugs from natural products. Isoimperatorin, an active natural furanocoumarin, exhibits a broad range of pharmacologic activities including anticoagulant, analgesic, anti-inflammatory, antibacterial, anti-tumor, and other pharmacological effects, so it has attracted more and more attention. In this study, the antiviral and mechanistic effects of isoimperatorin on influenza A virus in vitro were studied. Isoimperatorin illustrated a broad-spectrum antiviral effect, especially against the A/FM/1/47 (H1N1), A/WSN/33 (H1N1, S31N, amantadine resistant), A/Puerto Rico/8/34 (H1N1), and A/Chicken/Guangdong/1996 (H9N2) virus strains. The experimental results of different administration modes showed that isoimperatorin had the best antiviral activity under the treatment mode. Further time-of-addition experiment results indicated that when isoimperatorin was added at the later stage of the virus replication cycle (6–8 h, 8–10 h), it exhibited an effective antiviral effect, and the virus yield was reduced by 81.4 and 84.6%, respectively. In addition, isoimperatorin had no effect on the expression of the three viral RNAs (mRNA, vRNA, and cRNA). Both the neuraminidase (NA) inhibition assay and CETSA demonstrated that isoimperatorin exerts an inhibitory effect on NA-mediated progeny virus release. The molecular docking experiment simulated the direct interaction between isoimperatorin and NA protein amino acid residues. In summary, isoimperatorin can be used as a potential agent for the prevention and treatment of influenza A virus.

Influenza A virus infects pulmonary microvascular endothelial cells leading to microvascular leakage and release of pro-inflammatory cytokines

“…Madin-Darby canine kidney (MDCK) cell was a gift from the Institute of Respiratory Diseases of Guangzhou Medical University and the State Key Laboratory of Respiratory Diseases (Guangzhou, China). MDCK cells were maintained in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum, 100 U/ml penicillin, and 100 U/ml streptomycin at 37 °C under 5% CO 2 ( Lai et al, 2021 ). The human lung microvascular endothelial cell (HULEC-5a) was obtained from The Global Bioresource Center (ATCC CRL-3244).…”

“…The experimental method of plaque reduction was based on a previous description ( Furuta et al, 2002 ), as follows: MDCK cells (6 ×10 5 cells/well) were seeded in 12-well plates and cultured at 37 °C under 5% CO 2 for 24 h ( Lai et al, 2021 ). After infection with influenza virus, MOI 0.01, MDCK, and HULEC-5a cells were incubated for 48 h. The cells were then washed with phosphate buffer saline (PBS) and the supernatants collected from the virus-infected HULEC-5a and MDCK cells.…”

“…Next, the cell monolayers were overlaid with agar overlay medium (DMEM supplemented with 1% low melting point agarose and 2.5 µg/ml TPCK-treated trypsin) and incubated at 37 °C for 3 days. The cell monolayers were fixed with 4% paraformaldehyde for 2 h, the agarose overlays were then removed, and the cell monolayers were stained with 2%(w/v) crystal violet ( Lai et al, 2021 ).…”

“…DAVID ( https://david.ncifcrf.gov/tools.jsp ) was used to perform GO analysis, including biological process (BP), cellular component (CC), molecular function (MF), and KEGG Pathway analysis. The terms with a p -value of less than 0.05 were selected for functional annotation and signaling pathway clustering ( Huang, Sherman & Lempicki, 2009a ; Huang, Sherman & Lempicki, 2009b ; Lai et al, 2021 ).…”

An Efficient Ionic Liquid-Mediated Extraction and Enrichment of Isoimperatorin from Ostericum koreanum (Max.) Kitagawa

“…[27][28][29][30][31]. Isoimperatorin (Figure 1) is a naturally occurring furanocoumarin present in this herb, and it has been reported that isoimperatorin exhibits potent antitumor [32][33][34], antibacterial [35,36], anti-inflammatory [37], analgesic [38], antioxidant [39][40][41] and antiviral [42,43] properties. Most studies involving the separation of isoimperatorin and related compounds from the roots of O. koreanum focus on the determination of relative quantities and biological efficacies, as well as the origin discrimination of the plant materials [44][45][46].…”