Broad antiviral and anti-inflammatory activity of Qingwenjiere mixture against SARS-CoV-2 and other human coronavirus infections

BACKGROUND: Qingwenjiere Mixture (QJM) is a traditional Chinese medicine (TCM) that has been shown to have remarkable clinical efficacy against COVID-19. However, little is known about the antiviral and anti-inflammatory activities of QJM against a wider range of human coronavirus (HCoV) strains. PURPOSE: The study aims to investigate the antiviral and anti-inflammatory activities of QJM, as well as the underlying mechanisms against HCoV infections. METHODS: The chemical compositions from QJM were analyzed by LC-MS. The inhibitory effect of QJM on infections of HCoV-OC43, HCoV-229E, HCoV-NL63, and SARS-CoV-2 was evaluated in HRT-18 cells, Huh7 cells, LLC-MK2 cells, and Vero-E6 cells, respectively, by using cytopathic effect (CPE) inhibition assay or RT-qPCR detection of viral n, s, or RdRp/Hel genes. The expression of pro-inflammatory cytokines induced by HCoV-OC43, HCoV-229E, and SARS-CoV-2, as well as the host ace2 gene was also determined by RT-qPCR assay. Furthermore, the expression of key molecules in the NF-κB/MAPKs signaling pathways was determined by western blot. RESULTS: In alcohol-extraction groups of QJM and reference decoction pieces, 53 similar ion peaks were identified, the majority of which were phenylpropanoids, iridoids, and flavonoids. In addition, QJM reduced CPE caused by HCoVs and the expression of viral n genes or N protein. Pretreatment with QJM also exerted inhibitory effect on viral n gene expression. QJM also inhibited the expression of RdRp/Hel and s genes of SARS-CoV-2, as well as the host ace2 gene. Besides, QJM markedly reduced virus-induced mRNA expression of a panel of pro-inflammatory cytokines, such as IL-6, CXCL-8/IL-8, CXCL-10/IP-10, CCL-5/RANTES, TNF-α, IFN-α, CCL-2/MCP-1, CXCL-9/MIG, and IL1-α. We further showed that QJM inhibited the phosphorylation of NF-κB p65, and JNK, ERK 1/2, and p38 MAPKs in HCoV-OC43-infected HRT-18 cells. CONCLUSIONS: QJM has broad antiviral and anti-inflammatory activity against both common and newly emerged HCoVs possibly by inhibiting the activation of key components in NF-κB/MAPKs signaling pathway. QJM also has a prevention effect against HCoV infections and inhibits the host receptor required for virus entry. These results indicate that QJM may have the therapeutic potential in the treatment of diseases caused by a broad range of HCoVs.