Eckol protects against acute experimental colitis in mice: Possible involvement of Reg3g

Abstract

Abstract The anti-inflammatory activity of eckol, a phlorotannin constituent of marine brown algae, has been widely demonstrated. Here, we found eckol at doses of 0.5–1.0 mg/kg protected against development of dextran sulfate sodium (DSS)-induced acute experimental colitis in mice. DSS-elevated colonic tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 levels as well as nuclear factor kappa B(NF-κB)p65 and Toll like receptor (TLR)-4 expression were significantly suppressed, the colonic IL-10 level was enhanced in the eckol-treated mice. TUNEL-positive cells and Caspase-9 expression were downregulated in eckol-treated colons compared to DSS controls. Eckol inhibited the growth of potential gut pathogens and increased beneficial bacteria in colitic mice, and recruited CD11c+ dendritic cells (DCs) into inflamed colonic tissues. Colonic expression of regenerating islet-derived 3 gamma (Reg3g) was significantly increased by eckol. Overall, eckol represents a treatment alternative in colitis management. The induction of colonic Reg3g may account for the anti-inflammatory, anti-apoptotic, antimicrobial and immunoregulatory activities of eckol in colitic mice.