Immunomodulatory Activity and Protective Effects of Polysaccharide fromEupatorium adenophorumLeaf Extract on Highly Pathogenic H5N1 Influenza Infection

Abstract

The development of novel broad-spectrum, antiviral agents against H5N1 infection is urgently needed. In this study, we evaluated the immunomodulatory activities and protective effect of Eupatorium adenophorum polysaccharide (EAP) against the highly pathogenic H5N1 subtype influenza virus. EAP treatment significantly increased the production of IL-6, TNF-α, and IFN-γ both in vivo and in vitro as measured by qPCR and ELISA. In a mouse infection model, intranasal administration of EAP at a dose of 25 mg/kg body weight prior to H5N1 viral challenge efficiently inhibited viral replication, decreased lung lesions, and increased survival rate. We further evaluated the innate immune recognition of EAP, as this process is regulated primarily Dectin-1 and mannose receptor (MR). These results indicate that EAP may have immunomodulatory properties and a potential prophylactic effect against H5N1 influenza infection. Our investigation suggests an alternative strategy for the development of novel antiinfluenza agents and benefits of E. adenophorum products.

Carrot Pomace Polysaccharide (CPP) Improves Influenza Vaccine Efficacy in Immunosuppressed Mice via Dendritic Cell Activation

“…Furthermore, genetic engineering approaches may allow for low production costs and even facilitate oral delivery. In animal infection models, polysaccharides from Panax ginseng polysaccharide were shown to be protective against H1N1 and H3N2 influenza viruses [ 10 ], and the Eupatorium adenophorum polysaccharide improved the protective efficacy of the H5N1 vaccine [ 11 ]. More recently, mannan conjugated to a whole inactive H1N1 influenza virus was reported to elicit higher serum IgG than immunization with the virus alone [ 12 ].…”

Preparation, Phytochemical Investigation, and Safety Evaluation of Chlorogenic Acid Products from Eupatorium adenophorum

“…A number of compounds with bioactivity have been reported in E. adenophorum . Among them, chlorogenic acid, polysaccharides, and flavonoids are the main bioactive components in leaves of E. adenophorum [ 5 , 6 , 9 , 27 ]. Their contents in different products are presented in Table 1 .…”

“…In recent years, phytochemical investigations of E. adenophorum have led to the isolation of several bioactive compounds. Polysaccharides from E. adenophorum leaves have immunomodulatory properties and a potential prophylactic effect against H5N1 influenza infection [ 5 ]. Flavonoids from E. adenophorum have antioxidant and antibacterial bioactivities [ 6 , 7 ].…”

Eupatorium fortunei and Its Components Increase Antiviral Immune Responses against RNA Viruses

“…In addition, extracts of some Eupatorium species and their components have been reported to exhibit antiviral effects; for example, euparin isolated from E. chinense exhibits antiviral activities against respiratory syncytial virus (Wang et al, 2016 ), the hydroalcoholic extract of E. perfoliatum exhibits antiviral activities against influenza A virus that are mediated by interaction with the viral hemagglutinin (Derksen et al, 2016 ), E. adenophorum polysaccharide confers protective effects against H5N1 influenza infection (Jin et al, 2013 ), euparin from E. buniifolium exhibits antiviral activities against poliovirus type 1 (Visintini Jaime et al, 2013 ) and pseudorabies virus strain RC/79 (Zanon et al, 1999 ), and essential oils of E. patens inactivates HSV-1 (Garcia et al, 2003 ). Furthermore, extracts of E. buniifolium and E. articulatum exhibited antiviral effects against HSV-1 and VSV, respectively, and E. glutinosum inhibits VSV replication (Abad et al, 1999 ).…”