Methylsulfonylmethane (MSM), naturally occurring in green plants, fruits and vegetables, has been shown to
exert anti-inflammatory and antioxidant effects. MSM is an organosulfur compound and a normal oxidative
metabolite of dimethyl sulfoxide. This study was carried out to investigate the effect of MSM in a rat model of
experimental colitis. Colitis was induced by intracolonic instillation of 1 ml of 5% of acetic acid. Rats were
treated with MSM (400 mg/kg/day, orally) for 4 days. Animals were euthanized and distal colon evaluated
histologically and biochemically. Tissue samples were used to measurement of malondialdehyde (MDA),
myeloperoxidase (MPO), catalase (CAT), glutathione (GSH) and proinflammatory cytokine (TNF-α and IL-1β)
levels. Results showed that MSM decreased macroscopic and microscopic colonic damage scores caused by
administration of acetic acid. MSM treatment also significantly reduced colonic levels of MDA, MPO and IL-1β,
while increased the levels of GSH and CAT compared with acetic acid-induced colitis group. It seems that MSM
as a natural product may have a protective effect in an experimental ulcerative colitis
