Involvement of PPARγ in the protective action of tropisetron in an experimental model of ulcerative colitis

Abstract

Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal (GI) tract. Tropisetron, a selective 5-HT₃ receptor antagonist, is highly used to counteract chemotherapy-induced emesis. Previous studies revealed the anti-inflammatory properties of this drug. The aim of this study was to evaluate the role of peroxisome proliferator-activated receptor gamma (PPARγ) receptor in the protective effect of tropisetron in an animal model of ulcerative colitis. Experimental colitis was induced by a single intra-colonic instillation of 4% (V/V) acetic acid in male rats. Tropisetron (3 mg/kg) and GW9662 (PPARγ antagonist) (5 mg/kg) were given twice daily for 2 days after colitis induction. Forty-eight hours after induction of colitis, colon was removed and macroscopic and microscopic features were given. Moreover, colonic concentrations of malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels, myeloperoxidase (MPO), and PPARγ activity were assessed. Both macroscopic and histopathological features of colonic injury were markedly ameliorated by tropisetron. Likewise, levels of NO, MDA, TNF-α, and IL-1β diminished significantly (p < .05). GW9662 reversed the effect of tropisetron on these markers partially or completely. In addition, tropisetron increased the PPARγ and decreased the MPO activity (p < .05). Tropisetron exerts notable anti-inflammatory effects in acetic acid-induced colitis in rats, which is probably mediated through PPARγ receptors.

Keywords:

• Tropisetron
• PPARγ
• 5-HT₃ receptor
• ulcerative colitis
• rat

Disclosure statement

The authors declare no conflict of interest.

Funding

Support for this study was provided by Iran University of Medical Sciences (IUMS), Tehran, and Bushehr University of Medical Sciences (BUMS), Bushehr, Iran.