Effects of dietary supplementation of glucosamine sulfate on intestinal inflammation in a mouse model of experimental colitis

BACKGROUND AND AIM: Epidemiological evidences suggested an inverse association between the use of glucosamine supplements and colorectal cancer (CRC) risk. In this study, the efficacy of glucosamine to attenuate dextran sodium sulfate (DSS)-induced colitis, a precancerous condition for CRC, was evaluated. METHODS: C57BL/6 mice were separated into three groups receiving glucosamine sulfate at concentrations of 0, 0.05, and 0.10% (w/w) of AIN-93G diet, respectively for 4 weeks. Colitis was induced by supplying two cycles (5 days per cycle) of 2% DSS in the animals' drinking water. RESULTS: Glucosamine supplementation at the level of 0.10% of the diet (w/w) reduced colitis-associated symptoms as measured by disease activity index (DAI). Tumor necrosis factor-α (TNF-α), interleukin-1β, and nuclear factor-kappa B mRNA expression in the colonic mucosa was significantly lower in animals fed 0.10% glucosamine compared with those of the control group. Expression of the tight junction proteins ZO-1 and occludin was significantly higher in the 0.10% glucosamine-supplemented group compared with the other groups. Also, colonic protein expression of lipocalin 2, and serum concentrations of interleukin-8 and amyloid P component (SAP) were significantly reduced in the 0.10% glucosamine-supplemented group compared with the control group. CONCLUSION: These results suggest that glucosamine attenuates the colitis disease activity by suppressing NF-κB activation and related inflammatory responses.