Inflammatory bowel disease (IBD) is a chronically relapsing
inflammation of the gastrointestinal tract, of which the definite etiology remains ambiguous. Considering the adverse effects and incomplete efficacy of currently administered drugs, it is indispensable to explore new candidates with more desirable therapeutic profiles. 5-HT( 3) receptor antagonists have shown
analgesic and anti-inflammatory properties in vitro and in vivo. This study aims to investigate
granisetron, a 5-HT( 3) receptor antagonist, in
acetic acid-induced rat
colitis and probable involvement of 5-HT(3) receptors.
Colitis was rendered by instillation of 1 mL of 4%
acetic acid (vol/vol) and after 1 hour,
granisetron (2 mg/kg),
dexamethasone (1 mg/kg), meta-chlorophenylbiguanide (
mCPBG, 5 mg/kg), a 5-HT( 3) receptor agonist, or
granisetron +
mCPBG was given intraperitoneally. Twenty-four hours following
colitis induction, animals were sacrificed and distal colons were assessed macroscopically, histologically and biochemically (
malondialdehyde,
myeloperoxidase,
tumor necrosis factor-alpha,
interleukin-1 beta and
interleukin-6).
Granisetron or
dexamethasone significantly (p < .05) improved macroscopic and histologic scores, curtailed
myeloperoxidase activity and diminished colonic levels of inflammatory
cytokines and
malondialdehyde. The protective effects of
granisetron were reversed by concurrent administration of
mCPBG. Our data suggests that the salutary effects of
granisetron in
acetic acid colitis could be mediated by 5-HT(3) receptors.