Fucoidan prevents concanavalin A-induced liver injury through induction of endogenous IL-10 in mice.

Fucoidan is a complex of sulfated polysaccharides derived from non-mammalian origin such as marine brown algae and induces cytokine expression. We investigated the effect of fucoidan on concanavalin A (Con A)-induced liver injury in mice. Liver injury was induced by an intravenous injection of Con A (18.5mg/kg). Various doses of fucoidan (1-30mg/kg) were intravenously administered 30min before Con A injection. The plasma alanine aminotransferase (ALT) and several cytokines levels were determined, and hepatic histological changes were also assessed. The effect of fucoidan administration by itself on induction of interleukin (IL)-10 in plasma and liver tissue was investigated. Con A administration induced an elevation of plasma ALT level, and fucoidan administration dose-dependently prevented the Con A-induced elevation of plasma ALT. Con A administration increased plasma TNF-alpha and IFN-gamma levels, and fucoidan pretreatment significantly inhibited these alterations and increased plasma IL-10 level. The inhibitory effect of fucoidan on Con A-induced liver injury and production of proinflammatory cytokines were reversed by anti-mouse IL-10 antibody pretreatment. Fucoidan induced the IL-10 production in plasma and liver tissue. These findings suggest that fucoidan prevents Con A-induced liver injury by mediating the endogenous IL-10 production and the inhibition of proinflammatory cytokine in mice.