Peripheral lymphocyte DNA damage and oxidative stress in patients with ulcerative colitis

Introduction: Ulcerative colitis (UC) is a fairly common chronic inflammatory condition. Chronic inflammation may contribute to colorectal cancer risk through the accumulation of specific products as a result of DNA damage. Previous studies reported that DNA damage and oxidative stress have an important role in the pathophysiology of UC but the results are controversial. Objectives: In the present study, we investigated peripheral DNA damage and oxidative stress in patients with UC. Patients and methods: Twenty patients with UC and 20 controls were enrolled in the study. Peripheral lymphocyte DNA damage was assayed using alkaline comet assay. Plasma total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined.Results: DNA damage levels, TOS and OSI were significantly higher in UC than controls (all, p<0.001), while TAC were significantly lower (p<0.001). DNA damage was significantly correlated with TOS, TAC and OSI (r=0.604, p<0.001; r=-0.593, p<0.001, r=0.716, p<0.001; respectively). Moreover, TAC levels were significantly correlated with TOS and OSI (r=0.604, p<0.001; r=-0.399, p<0.05, r=-0.513, p<0.05; respectively). Conclusions: Our results shown that increased peripheral DNA damage and oxidative stress seems to be associated with decreased antioxidant levels and thus, may in part, be contribute to in the development UC-associated colorectal cancer.