Objectives: 

Oxidative stress is a potential etiological and/or triggering factor for intestinal inflammation due to the detrimental effects of free radicals in the inflammatory process. In addition, intestinal inflammation increases the susceptibility to oxidative damage. Serotonin (5-HT) and TNF-alpha play an important role in intestinal inflammation and have been demonstrated to contribute to oxidative stress. IL-10 is an anti-inflammatory cytokine also involved in intestinal inflammatory processes; however, the role of IL-10 on intestinal oxidative stress remains unknown. The aim of the present study was to determine the IL-10 effect on oxidative stress induced by 5-HT and TNF-alpha in the intestinal epithelium.

Materials: 

Human enterocyte-like Caco-2 cells were used, and the oxidative stress was determined by measuring lipid peroxidation (MDA + 4HDA) and protein carbonyls, and the activity of the antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx).

Results: 

The results showed that IL-10 treatment did not induce either oxidative damage in lipids and proteins or alteration of the activity of the antioxidant enzymes assayed. However, IL-10 seems to reverse the oxidation of lipids and proteins caused by 5-HT and TNF-alpha. Moreover, IL-10 reversed the inhibition of catalase activity induced by 5-HT, and it increased the activity of SOD in cells treated with either 5-HT or TNF-alpha. In relation to GPx activity, none of the treatments assayed showed effects.

Conclusions: 

Our study demonstrate that IL-10, a well know anti-inflammatory cytokine, may also act like an antioxidant factor and it might contribute to the modulation of the intestinal inflammatory process.