Ameliorative effects of alginate oligosaccharide on tumour necrosis factor-α-induced intestinal epithelial cell injury

Abstract

Alginate oligosaccharide (AOS), produced by the depolymerisation of alginate (a polysaccharide naturally present in certain species of brown algae), has been shown to have versatile biological functions. In the present study, the porcine small intestinal epithelial cell line IPEC-J2 was used to assess the ameliorative effects of AOS on tumour necrosis factor-α (TNF-α)-induced intestinal epithelial cell injury. IPEC-J2 cells were pre-treated with or without AOS (600 μg/mL) in the presence or absence of TNF-α (50 ng/mL) for 24 h. AOS pre-treatment increased (P < 0.05) the occludin protein abundance and decreased (P < 0.05) the cytokine (interleukin-6 and TNF-α) concentrations, apoptosis rate and cysteinyl aspartate-specific protease-3 (caspase-3) and caspase-8 activities in TNF-α-treated IPEC-J2 cells. In addition, AOS pre-treatment increased (P < 0.05) the content of cellular inhibitor of apoptosis protein 2 and decreased (P < 0.05) the expression levels of TNF receptor 1 (TNFR1), TNFR-associated death domain protein and Fas-associated death domain protein in TNF-α-treated IPEC-J2 cells. These results demonstrate that AOS can reduce TNFR1-mediated apoptosis, thereby alleviating TNF-α-induced inflammatory injury in intestinal epithelial cells.