Dietary astaxanthin inhibits colitis and colitis-associated colon carcinogenesis in mice. - GreenMedInfo Summary
Dietary astaxanthin inhibits colitis and colitis-associated colon carcinogenesis in mice via modulation of the inflammatory cytokines.
Chem Biol Interact. 2011 May 20. Epub 2011 May 20. PMID: 21621527
School of Veterinary Medicine, Rakuno Gakuen University, 069-8501 Hokkaido, Japan; Department of Oncologic Pathology, Kanazawa Medical University, 920-0293 Ishikawa, Japan.
Astaxanthin (AX) is one of the marine carotenoid pigments, which possess powerful biological antioxidant, anti-inflammatory and anti-cancer properties. The purpose of this study is to investigate possible inhibitory effect of AX against inflammation-related mouse colon carcinogenesis and dextran sulfate sodium (DSS)-induced colitis in male ICR mice. We conducted two different experiments. In the first experiment, we evaluated the effects of AX at three dose levels, 50, 100 and 200ppm in diet, on colitis-associated colon carcinogenesis induced by azoxymethane (AOM)/DSS in mice. In the second, the effects of the AX (100 and 200ppm) in diet on DSS-induced colitis were determined. We found that dietary AX significantly inhibited the occurrence of colonic mucosal ulcers, dysplastic crypts, and colonic adenocarcinoma at week 20. AX-feeding suppressed expression of inflammatory cytokines, including nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α and interleukin (IL)-1β, inhibited proliferation, and induced apoptosis in the colonic adenocarcinomas. Feeding with 200ppm AX, but not 100ppm, significantly inhibited the development of DSS-induced colitis. AX feeding (200ppm in diet) also lowered the protein expression of NF-κB, and the mRNA expression of inflammatory cytokines, including IL-1β, IL-6, and cyclooxygenase (COX)-2. Our results suggest that the dietary AX suppresses the colitis and colitis-related colon carcinogenesis in mice, partly through inhibition of the expression of inflammatory cytokine and proliferation. Our findings suggest that AX is one of the candidates for prevention of colitis and inflammation-associated colon carcinogenesis in humans.