The effects of ethanol extracts of rice bran, red adlay and Echinacea spp roots on alleviating colitis in DNBS-induced mice - 農業知識入口網

Abstract

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) with a frequent relapse inflammation in the colon, which may result in diarrhea,
dehydration and perforation. The etiology of  UC remains unknown. Several dietary components with anti-oxidant and antiinflammatory activities
have been reported to prevent the recurrence of UC. The aim of this study was to  investigate the effects of the ethanol extracts of rice bran, red adlay,
Echinacea purpurea roots and E. pallida roots on alleviating the clinical symptoms, inflammation and colon damages in UC. Male C57BL/6JNarl mice
were intra-rectally injected with 2,4-dinitrobenzene sulfonic acid (DNBS, 200 mg/kg) to induce colitis (day 0). From day 3 to 24, UC mice were fed
with the AIN-93M diet (UC group) or the diet supplemented with 70% ethanol extracts of rice bran (RBE group), red adlay (ADE group), E. purpurea
roots (PEP group) or a mixture of E. purpurea and E. pallida roots  (APP group). These mice were re-activated by DNBS (100 mg/kg) on day 21 to
mimic colitis relapse and killed on day 24. Healthy normal rats fed with AIN-93M diet (R group) were included as  controls. The results showed that
the UC group had significantly higher levels of disease activity index (DAI) and plasma glutathione and lower levels of plasma interleukin (IL)-10 and
colonic  claudin 4 than the R group (p<0.05, one-way ANOVA and Duncan's multiple range test). In the colon, the scores of edema, immune cell
infiltration, loss of goblet cells and inflammation were significantly higher in the UC group than in the R group (p<0.05, Kruskal Wallis test and Mann 
Mann–Whitney U test). In addition, the PEP group had increased plasma IL-6; the RBE  had increased colonic claudin 4; the PEP and APP groups had
decreased colonic occludin; the ADE, PEP and APP groups had increased colonic collagen content; and the RBE ADE, PEP and APP groups had
significantly decreased plasma TNF-α, IFN-γ, IL-10, IL-12p70 and MCP-1 and glutathione compared to the UC group. In conclusion, oral
administration of ethanol extracts of rice bran, red adlay and Echinacea roots may mitigate the innate and adaptive immune responses and reversed
the UC-increased colonic GSH content in UC mice. In addition, the ethanol extract of  rice bran may have beneficial effects in preserving the colonic
integrity in UC mice. However, the adverse effects of ethanol extracts of red adlay and Echinacea roots on colonic fibrosis need to be concerned.