ABSTRACT
BACKGROUND: Encephalitis in hand, foot, and mouth disease (HFMD) is a serious threat to children's health and life. Toll-like receptor 3 (TLR3) is an innate immune-recognition receptor that can recognize virus and initiate innate immune responses. Emodin has the effects of anti-inflammatory and regulating immune function, but the mechanism is not very clear. METHODS: Cells and mice were pretreated with coxsackievirus B3m (CVB3) and treated with emodin. The messenger ribonucleic acid (mRNA) and protein levels of TLR3 and downstream molecules were detected by quantitative real-time polymearse chain reaction and western blotting analysis, respectively. TLR3 expression was also downregulated by anti-TLR3 antibody (TLR3Ab) or small interfering RNA (siRNA). Pathological changes were assessed with hematoxylin and eosin staining. Immunohistochemistry was used to examine the expression of TLR3 in brain tissues. The expression of interleukin (IL)-6, nuclear factor (NF)-κB, and interferon (IFN)-ß in serum were tested with enzyme-linked immunosorbent assay. RESULTS: Emodin decreased the mRNA and protein levels of TLR3 and downstream molecules in vitro and in vivo. After downregulating TLR3 using anti-TLR3Ab or siRNA, emodin could still decrease the mRNA and protein levels of TLR3 and downstream molecules. Emodin also displayed notable effects on pathology, TLR3 protein in brain tissues, and expression of IL-6, NF-κB, IFN-ß, in serum. CONCLUSIONS: Emodin exerts a protective effect in CVB3-mediated encephalitis in HFMD by inhibiting the TLR3 pathway.
Subject(s)
Emodin/pharmacology , Encephalitis/drug therapy , Hand, Foot and Mouth Disease/virology , Signal Transduction/drug effects , Toll-Like Receptor 3/metabolism , Animals , Blotting, Western , Cells, Cultured , Encephalitis/immunology , Encephalitis/virology , Enterovirus/immunology , Enzyme-Linked Immunosorbent Assay , Immunity, Innate , Interferon-beta/metabolism , Interleukin-6/metabolism , Male , Mice , Mice, Inbred BALB C , NF-kappa B/metabolism , RNA, Messenger/drug effects , Toll-Like Receptor 3/geneticsABSTRACT
Infectious diseases are the common enemies of mankind. In the course of historical development, they persistently threaten human health and safety. Even today, despite the developments in medical science, we cannot escape the fear and suffering caused by infectious diseases. Whether in ancient or modern times, the source of infection, route of transmission, and a susceptible population are the three key conditions for the prevalence and spread of infectious diseases. All factors closely related to these three conditions can affect the prevalence of infectious diseases. China is one of the cradles of world civilization. The ancient people accumulated a great deal of experience and lessons in the long struggle against infectious diseases. In the face of the current threat posed by widespread infectious disease, it is imperative to review and summarize ancient Chinese ideas and health policies on epidemic prevention and control to inspire contemporary efforts in the prevention and control of infectious disease. The combination of prevention-oriented epidemic prevention ideology and traditional medicine provides valuable insights, especially for impoverished and medically underserved regions.