The researchers claim the findings of their study suggest that the anti-inflammatory effects of resveratrol seem to be related to a cytokines modulation and a reduction of PGES-1, COX-2 and iNOS expression in colonic mucosa, in addition to other possible mechanisms, via down regulation of p-38 MAPK pathway.
The research was published in the European Journal of Pharmacology.
The authors note no previous research undertaken on dietary resveratrol in relation to chronic colitis and thus their goal was to examine the protective/preventive effects of dietary resveratrol intake on chronic dextran sulphate sodium (DSS)-induced colitis to help identify and validate new therapies for treatment of inflammatory bowel disease (IBD).
They explain that IBD is a chronic pathology by uncontrolled inflammation of the intestinal mucosa which can affect part of the gastrointestinal tract, with causes including genetic factors, immune dysregulation, barrier dysfunction, and a loss of immune tolerance toward the enteric flora.
Reported benefits of resveratrol
Resveratrol (trans-3,4,5-trihydroxystilbene), a natural polyphenol, is found in a large number of fruits and vegetables and is abundant in grapes and in red wines.
Recent studies looking at the benefits of resveratrol have reported anti-cancer effects, anti-inflammatory effects, cardiovascular benefits, anti-diabetes potential, energy endurance enhancement, and protection against Alzheimer’s.
The authors said that six-week-old mice were randomized into two dietary groups, with one group on a standard diet and the other on a model enriched with resveratrol consuming an average of 3 g/day of diet resulting in a dose of 3 mg/kg body weight of resveratrol ingested.
The authors said that the administered dose of resveratrol was chosen based on analyses described in previoud studies and added that it was equivalent to 0.429 mg/kg/day in humans (30 mg resveratrol in a 70 kg person)
After 30 days, mice were exposed to 3 per cent DSS for five days developing acute colitis that progressed to severe chronic inflammation after 21 days of water, they added.
Results, said the research team, indicate that dietary administration of resveratrol reduced the severity and extension of progressive chronic colonic damage and also significantly counteracted the clinical signs such as loss of body weight, diarrhoea and rectal bleeding thus reducing the inflammatory process.
They said that three weeks after DSS removal, the polyphenol caused substantial reductions in the rise of pro-inflammatory cytokines, TNF-α and IL-1β and an increase of the anti-inflammatory cytokine IL-10.
The team reported an attenuation also of morphological signs of cell damage in the resveratrol group, with the colonic mucosa showing areas of exfoliation of epithelial cells, reduction of inflammatory cells infiltration and glandular hypertrophy, as well as some areas of intact epithelium.
Moreover, all of the resveratrol-fed animals survived and finished the treatment while animals fed with standard diet showed a mortality of 40 per cent, they said.
“An important finding was the high reduction of mortality in DSS resveratrol animals. The mechanism by which resveratrol reduces DSS-induced mortality are not clear, although its antioxidant, anti-inflammatory and anti-infectious properties may play a role,” stated the authors.
They thus concluded that a resveratrol diet represents a novel approach to the treatment of chronic intestinal inflammation.
Source: European Journal of Pharmacology
Published online ahead of print: doi:10.1016/j.ejphar.2010.01.025
Title: Dietary supplementation of resveratrol attenuates chronic colonic inflammation in mice
Authors: S. Sánchez-Fidalgo, A. Cárdeno, I. Villegas, E Talero, C. Alarcón de la Lastra