Tectorigenin Reduces Dabie bandavirus-Induced Cytokine Storm by Regulating Toll-Like Receptor 7/Extracellular Signal-Regulated Kinase Pathway

Severe fever with thrombocytopenia syndrome (SFTS) is a severe emerging infectious disease caused by Dabie bandavirus (DBV). Tectorigenin has been demonstrated to exert anti-inflammatory effect. Here, we aimed to investigate the effects of tectorigenin on DBV-induced cytokine storm. Effects of tectorigenin on cytokines in DBV-infected THP-1 cells and plasma samples of Type I interferon receptor (IFNAR) mice infected with DBV were detected. The changes in body weight and survival time of mice were recorded. The liver, spleen, kidney, and lymph node tissues were collected for hematoxylin-eosin staining. We demonstrated that tectorigenin reduced the expression levels of inflammatory cytokines in both DBV-infected THP-1 cells and plasma samples of IFNAR mice infected with DBV. Tectorigenin attenuated DBV-induced histopathological changes in mice. Mechanistically, tectorigenin attenuated DBV-induced phosphorylation of inhibitor of kappa-B kinase alpha/beta (IKKα/β) of the nuclear factor-κB (NF-κB) signaling pathway, extracellular signal-regulated kinase (ERK) of the mitogen-activated protein kinase (MAPK) signaling pathway and might function by downregulation of Toll-like receptor. The result of this study suggested that tectorigenin exerted anti-inflammatory effects in vivo and in vitro and could serve as a novel potential therapeutic strategy for SFTS.