Alliin, a garlic organosulfur compound, ameliorates gut inflammation through MAPK-NF-κB/AP-1/STAT-1 inactivation and PPARγ activation.
Mol Nutr Food Res. 2017 Mar 30. Epub 2017 Mar 30. PMID: 28371322
OBJECTIVE: In this study, the anti-inflammatory effects and the molecular mechanism of alliin were analyzed in dextran sulfate sodium (DSS)-induced colitis mice and lipopolysaccharide-stimulated RAW264.7 cell model.
METHODS: The phenotype of mice was recorded in the DSS-induced and/or alliin (500 mg/kg) groups. Histopathological alterations were analyzed by H&E staining. MPO and MDA of colon tissues were measured. The mRNA expression levels of inflammatory factors were determined by qRT-PCR, and protein expressions of inflammatory factors or activation of kinases were determined by Western blotting.
RESULTS: Oral administration of alliin significantly inhibited the decrease of body weight, improved the DAI and decreased the infiltration of inflammatory cells in colonic tissues. The content of NO, MDA and MPO, the expression of iNOS and inflammatory factors as well as MAPK and the phosphorylation of PPARγ were inhibited in alliin-treated group. Treatment with alliin significantly repressed the expression of inflammatory factors in LPS-stimulated RAW264.7 cells. Further research demonstrated that alliin repressed LPS-induced AP-1/NF-κB/STAT-1 activation by inhibiting the phosphorylations of p38, JNK and ERK1/2-regulated PPARγ activation.
CONCLUSION: Our results show that alliin ameliorates DSS-induced ulcerative colitis and inhibits the inflammatory responses in LPS-stimulated RAW264.7 cells partly through inhibiting ERK1/2-, JNK-/PPARγ-stimulated NF-κB/AP-1/STAT-1 activations and p38-induced STAT-1 activation. This article is protected by copyright. All rights reserved.