Orally administered allyl sulfides from garlic ameliorate murine colitis

Scope: Inflammatory bowel disease (IBD) is an incurable disease which affects millions of people. Garlic (Allium sativum) preparations have been traditionally employed for the treatment of diseases affecting the digestive tract. Here, we have investigated the effect of diallyl sulfide (DAS) and diallyl disulfide (DADS), two garlic-derived sulfur compounds, on intestinal inflammation in vivo as well as in intestinal isolated cells. Methods and results: Colitis was induced in mice by intracolonic administration of dinitrobenzenesulfonic acid. Intestinal damage was assessed by evaluating colon weight/colon length ratio and by histology. Murine intestinal epithelial cells stimulated with IFN-γ were used to evaluate the possible in vitro DAS and DADS anti-inflammatory effects. DAS and DADS, given for two consecutive days after DNBS administration, reduced inflammation and damage. In IFN-γ-stimulated intestinal epithelial cells, DADS reduced IP-10 and IL-6 levels, while DAS inhibited nitric oxide production and STAT-1 expression. Conclusion: DAS and DADS exert therapeutic effects in the DNBS model of colitis. The actions of these compounds on the production of IP-10, IL-6, hydrogen sulfide or nitric oxide and on the expression of STAT-1 observed in intestinal cells stimulated with IFN-γ, might explain the protective action of DAS and DADS in experimental IBD.