Promising results have recently been obtained with pre- and probiotic
therapy in
ulcerative colitis (UC). The
prebiotic potential of
lactulose is well established, but it has not yet been investigated in experimental
colitis models. The purpose of the study was to examine the effect of
lactulose on an UC model induced by 3%
dextran sulfate sodium (DSS)
solution added to
drinking water for 7 days in male Wistar rats.
Lactulose (300-1000 mg/kg) or
5-aminosalicylic acid (5-ASA; 150 mg/kg) was administered orally twice daily for 6 days. Colonic ulceration area, colon length,
body weight changes,
diarrhea/bloody feces, colonic mucosal
myeloperoxidase activity (MPO),
thiobarbituric acid reactive substances (
TBARS), and histology were examined. Treatment of animals with DSS for 7 days resulted in severe colonic lesions accompanied by
diarrhea, bloody feces, a decrese in
body weight, shortening of the colon length, and an increase in MPO activity as well as
TBARS, compared to normal rats.
Lactulose treatment ameliorated DSS-induced
colitis in a dose-dependent manner, and at 1000 mg/kg all of the parameters examined, except
TBARS, were shown to improve significantly as compared to controls. Daily administration of 5-ASA also significantly reduced the severity of colonic lesions following DSS treatment. These results demonstrated the protective effect of
lactulose in this rat
colitis model and suggested that the background of this
lactulose effect may be due to alterations of colonic microflora.