Melatonina moduluje uszkodzenia i napraw DNA w kolonocytach pacjentów z wrzodziej cym zapaleniem jelita grubego Melatonin modulates DNA damage and repair in colonocytes of subjects with ulcerative colitis

Introduction: Ulcerative colitis (UC) is a common chronic inflammatory condition. Previous studies reported that DNA damage might have an important role in the pathophysiology of UC. Melatonin is a hormone-like substance that has a variety of beneficial properties as a regulator of the circadian rhythm and as anti-inflammatory and anti-cancer agent. The latter activity can be linked with the ability of melatonin to protect DNA against oxidative damage. Aim of the study was to evaluate the level of DNA damage and repair in colonocytes of subjects with UC in the presence or absence of melatonin. Material and methods: Colonic biopsy specimens were obtained from 40 UC patients (22 women and 18 men, aged 23-62 years, mean age 39 years). In each of the studied subjects the biopsies were drawn both from the inflamed and normal mucosa as control. DNA damage and repair level in colonocytes was evaluated using alkaline comet assay. Results: Melatonin decreased the extent of DNA lesions induced by hydrogen peroxide and stimulated their repair in normal and inflamed mucosa. In the absence of melatonin the rate of DNA repair after 60 min was significantly higher in normal than inflamed mucosa (p <0.01). Conclusions: Melatonin may exert a protective effect against oxidative DNA damage and stimulate its repair in colonocytes of the UC subjects. Therefore, melatonin supplementation can have a beneficial therapeutic effect in patients with UC.