`study with comet assay, the effect of narrowbant uv-B and vitamin E on mutagenic risk in psoriasis vulgaris patients??

Psoriasis is a chronic, inflammatory, hyperproliferative and T cell immun-mediated skin disease with a genetic basis. Leukocytes are important source of reactive oxygen species. Consequently, this inflammatory skin disease contributes oxidative stress.Narrow band UVB is used as a therapeutic modality for psoriasis. Some studies indicate that cutaneous tissue, both in vivo and in vitro, generates free radicals and other reactive oxygen species following exposure to UVB.Vitamin E is the most important lipid soluble antioxidant in the body. Vitamin E not only acts as an effective lipophilic antioxidant and radical scavenger but also stabilizes cellular membranes.Oxidative stress causes DNA damage, which can contribute to the development of canser incidence. The Comet Assay (single cell gel electrophoresis) is a sensitive and rapid method to measure DNA single and double strand breaks.In our study, our aim was to evaluate the effects of narrow band UVB therapy on the occurence of DNA damage in psoriatic patients by using Comet Assay and whether, an antioxidant, vitamin E had an improvement role on this damage or not.Our study patients were no-smokers. Psoriatic patients were divided to two groups. 8 patients in group 1 were treated with narrow band UVB, and 10 patients in group 2 was treated with narrow band UVB plus oral 400 IU/day vitamin E (d, ? -tokoferol) for 45 days. None of these patients had received any systemic therapy for psoriasis before. Activity of disease in patients with psoriasis vulgaris was determined by means of the Psoriasis Area and Severity Index (PASI). PASI was determined before and after 45th day of treatment. The PASI of all patients had decreased significantly on 45th day of treatment. After treatment, comparison of PASI values of group 1 and 2 did not revealed a statistically significant difference. Therefore, it is considered that vitamin E may not have an effective role on clinical improvement of psoriasis.In group 1, the levels of DNA damage on 45.day was significantly higher than the 0.day levels. However, the 45.day levels of DNA damage in group 2 did not show statistically significant reduction as compared to the pretreatment levels. In this sudy it was demonstrated that narrow band UVB therapy achieved a statistically significant increase in DNA damage, and though it was not reflected to the statistical analysis, vitamin E supplementation provided a decrease in this UVB induced-DNA damage. Therefore, in order to decrease the carsinogenic risk of narrow band UVB adding vitamin E to narrow band UVB should be considered.