A marine-sourced fucoidan solution inhibits Toll-like-receptor-3-induced cytokine release by human bronchial epithelial cells

Abstract

Fucoidans are sulfated polysaccharides from brown algae, known to have immunomodulatory activity. Their effects on the response of airway epithelial cells to Toll-like receptor 3 (TLR3) stimulation have not been characterized. Our objective was to evaluate the effects of a marine-sourced fucoidan solution (MFS) on the TLR3-induced expression and/or production of cytokines and prostaglandin by human primary bronchial epithelial cells as a model of the airway epithelium. The cells were incubated with MFS in the presence or absence of Poly(I:C) (a TLR3 agonist that mimics viral RNA). Cytokine expression and production were assessed using RT-qPCR and ELISA. The expression of cyclooxygenase-2 and the production of prostaglandin E2 were also measured. Relative to control, exposure to MFS was associated with lower Poly(I:C)-induced mRNA expression of various cytokines and chemokines, and lower COX-2 production. The MFS inhibited the production of some cytokines (IL-1α, IL-1β, TNFα, and IL-6), chemokines (CCL5, CCL22, CXCL1, CXCL5 and CXCL8) and prostaglandin E2 but did not alter the production of IL-12/25, CCL2 and CCL20. At clinically relevant concentrations, the MFS inhibited the TLR3mediated production of inflammatory mediators by human primary bronchial epithelial cells -suggesting that locally applied MFS might help to reduce airway inflammation in viral infections.

Application prospect of polysaccharides in the development of anti-novel coronavirus drugs and vaccines

“…3 ) [ 37 ]. Fucoidan is a fucose-enriched and sulfated polysaccharide extracted from brown algae [ 11 , 38 ], which is composed of L-fucose, sulfate groups and small proportions of D-xylose, D-mannose, D-galactose, and D-glucuronic acid in different sources of brown algae ( Fig. 3 ) [ [38] , [39] , [40] ].…”

“…It is urgent for the international medical community to develop targeted, high-efficiency and low-toxic drugs to treat the coronavirus based on the structure and property of the coronavirus. Polysaccharides have been used in traditional Chinese herbal medicine for at least 500 years [ 11 ], and have advantages of wide sources, low toxicity, good biocompatibility, and immune regulation [ 12 , 13 ]. Some polysaccharides, such as carrageenan, chitosan, fucoidan, and astragalus polysaccharide (APS), have been reported to show strong antiviral activity [ [14] , [15] , [16] , [17] ].…”

The Potential of Algal Biotechnology to Produce Antiviral Compounds and Biopharmaceuticals

“…Fucoidans from Macrocystis pyrifera, A. nodosum , U. pinnatifida , and F. vesiculosus were found to improve immune function by activation of NK cells, DCs, and T cells. Recently, it was considered that fucoidan could inhibit the release of cytokines from human primary bronchial epithelial cells via the Toll-like receptor 3 (TLR3); suggesting that it could relief bronchial inflammation caused by viral infection when applied locally [ 143 ]. Based on results of numerous reports, fucans are promising antiviral agents.…”

Current Findings Regarding Natural Components With Potential Anti-2019-nCoV Activity

“…Griffithsin exhibits satisfactory anti-oxidation properties and antitumor activity, which both contribute to its anti-viral efficacy. Fucoidan is a cousin of griffithsin that is widely used to treat liver disease, cancer, and skin infections, due to its anti-inflammatory properties (Dutot et al, 2019 ). During the SARS outbreak, statistical analyses showed that Shandong Province more actively used fucoidan and recorded a significantly lower mortality rate, relative to other regions, possibly due to its “combined strengthening and elimination” abilities.…”