The goal of this study was to evaluate for evidence of oxidative stress in colonic
inflammation in a novel model of
inflammatory bowel disease, nonsteroidal anti-inflammatory
drug- (
NSAID-) treated interleukin-10-deficient (
IL10(-/-)) mice.
IL10(-/-) and wild-type (wt) mice were treated with a nonselective
NSAID (
piroxicam, 200 ppm in the diet) for 2 weeks to induce
colitis, and parameters for oxidative stress in the colonic tissues were evaluated. Mean chemiluminescence enhanced with
lucigenin in the colons from
IL10(-/-) mice treated with
piroxicam was more than 5-fold higher than that of the control wt group. Chemiluminescence was inhibited with diphenylethylene iodinium, but not
allopurinol,
indomethacin, or
N-omega-nitro-L-arginine, indicating that
flavin-containing
enzymes were the source of the
reactive oxygen species. Colonic
aconitase activity in
NSAID-treated
IL10(-/-) mice decreased to 50% of the activity of control mice. There was no difference in the total
glutathione levels in the colonic mucosa among the groups; however,
glutathione disulfide levels were approximately 2-fold greater in the colon of
NSAID-treated
IL10(-/-) mice as compared with control groups. Immunohistochemistry studies of colons from
NSAID-treated
IL10(-/-) mice demonstrated intense staining with two
antibodies that recognize
advanced glycation endproducts formed through glycation and oxidation: anticarboxymethylysine and antipentosidine. The epithelial cells and lamina propria cells in the colons of
NSAID-treated
IL10(-/-) mice showed immunostaining with antinitrotyrosine, indicating the presence of
reactive nitrogen species. Colonic epithelium of
IL10(-/-) mice with
colitis showed moderate immunostaining for
8-hydroxy-2'-deoxyguanosine in the nuclei.
NSAID-treated
IL10(-/-) mice treated with diphenylene idodonium
chloride (DPI), an irreversible inhibitor of
flavoprotein enzymes, experienced significantly reduced
inflammation. Taken together, these results strongly indicate the presence of oxidative stress in the
inflammatory bowel disease in
NSAID-treated
IL10(-/-) mice and suggests a role for oxidative stress in the pathophysiology of this model of
inflammatory bowel disease.