Cyclo-oxygenase-2 inhibitors ameliorate the severity of experimental colitis in rats.
BACKGROUND
Both in experimental colitis and in inflammatory bowel disease, colonic eicosanoid generation is enhanced and may contribute to the pathogenesis of the inflammatory response.


OBJECTIVE
To evaluate the effect of selective cyclo-oxygenase-2 (COX-2) inhibitors on the extent and severity of two models of experimental colitis.


METHODS
Colitis was induced by intra-caecal administration of 2 ml 5% acetic acid or intra-colonic administration of 0.1 ml 3% iodoacetamide. Rats were treated intra-gastrically with nimesulide 2 x 10 mg/kg/day, or once with SC-236 6 mg/kg, and killed 1 or 3 days after damage induction. The colon was isolated, weighed, macroscopic damage was measured, and mucosal samples were obtained for histology and for determination of myeloperoxidase (MPO) and nitric oxide synthase (NOS) activities and eicosanoid generation. The serum levels of thromboxane B2 (TXB2), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were determined.


RESULTS
Nimesulide significantly decreased the extent of colitis induced by acetic acid. Both nimesulide and SC-236 significantly decreased the extent of iodoacetamide-induced colonic damage. The decrease in the extent of colitis induced by nimesulide was accompanied by a significant decrease in mucosal MPO and NOS activities. Nimesulide and SC-236 decreased the enhanced colonic eicosanoid generation in acetic acid and iodoacetamide-induced colitis, and, in iodoacetamide-treated rats, nimesulide also decreased the elevated serum TNF-alpha and IL-1beta levels.


CONCLUSIONS
The effective nimesulide and SC-236-induced amelioration of the severity of the colitis in acetic acid and iodoacetamide-treated rats confirms the role of eicosanoids in their pathogenesis and suggests that COX-2 inhibitors may be of value in the treatment of inflammatory bowel disease.
Karmeli
F
F
Department of Medicine, Hadassah University Hospital, Mount Scopus, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Cohen
P
P
Rachmilewitz
D
D
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D003092:Colitis / Q000188:drug therapy*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D015777:Eicosanoids / Q000378:metabolism; D007213:Indomethacin / Q000494:pharmacology / Q000627:therapeutic use; D007249:Inflammation; D007375:Interleukin-1 / Q000097:blood; D008297:Male; D019001:Nitric Oxide Synthase / Q000187:drug effects; D009195:Peroxidase / Q000187:drug effects; D011720:Pyrazoles / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D013449:Sulfonamides / Q000494:pharmacology / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D000096926:Benzenesulfonamides
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016861:Cyclooxygenase Inhibitors; D015777:Eicosanoids; D007213:Indomethacin; D007375:Interleukin-1; D019001:Nitric Oxide Synthase; D009195:Peroxidase; D011720:Pyrazoles; D013449:Sulfonamides; D014409:Tumor Necrosis Factor-alpha; C119130:4-(5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl)benzenesulfonamide; D000096926:Benzenesulfonamides; C012655:nimesulide