Determination of UV induced genotoxic activity by comet assay with in vitro skin models developed by co-culture of healty and melanoma cell lines

It is estimated that exposure to UV radiation, in particular, is 10% for adults working in the open air and 3% for the total available annual UV radiation (horizontal plane) for indoor adults. Given the potential of harmful health effects such as sunburn, eye damage, photoaging, immune system disorders, DNA damage, and skin cancer, it is necessary to determine the genetic damage caused by UV rays. In the scope of the project, determination of genetic damage caused by UV radiation done by in vitro genotoxicity methods, comet assay and fluorescence micronucleus assay, as an alternative to in vivo methods. At the same time, testing the efficiancy of β-carotene, which is frequently used in UV protection in dermocosmetic products, is one of the aims of the thesis. In this study, we determined that UV rays cause genetic damage and β-carotene active ingredient, which is commonly used in sun creams and cosmetic products, is a protective factor against this damage especially when applied before exposure to UV rays. (Comet assay: in co-culture system, HaCat cell line: UV: 85,638%, β- Carotene + UV: 18,67%, UV + β- Carotene: 38,18%, SK-MEL 30 cell line: UV: 91,13%, β- Carotene + UV: 23,67%, UV + β- Carotene: 27,77%, Detroit 551 cell line: UV: 27,19%, β- Carotene + UV: 5,35%, UV + β- Carotene: 9,03%- in other experiment sets, HaCat cell line: UV: 85,638%, β- Carotene + UV: 16,92%, UV + β- Carotene: 22,39%, SK-MEL 30 cell line: UV: 81,68%, β- Carotene + UV: 16,86%, UV + β- Carotene: 45,35%, Detroit 551 cell line: UV: 87,74%, β- Carotene + UV: 29,29%, UV + β- Carotene: 37,43%, Fluorescence micronukleus assay; in co-culture system, Detroit 551 cell line with HaCat cell line: UV: 2%, β- Carotene + UV: 0%, UV + β- Karoten: 1%; Detroit 551 cell line with SK-MEL 30 cell line: UV: 5%; β- Carotene + UV: 3%, UV + β- Carotene: 3%- in other experimental sets: HaCat cell line; UV: 30%, β- Carotene + UV: 7%, UV + β- Carotene: 16%, Detroit-551 cell line; UV: 25%, β- Carotene + UV: 7%, UV + β- Carotene: 13%, SK-MEL 30 cell line: UV: 20%, β- Carotene + UV: 3%, UV + β- Carotene: 8%). With the optimization of the applied methods, it has been observed that the co-culture system does not provide full efficiency, it did not pass through the insert surface of the radically genotoxic substances such as UV radiation, it did not affect the cells in the lower layer of the culture, but it is an effective system in β-carotene which is used together with the common nutrient medium. Also in this study comet analysis and fluorescence micronucleus methods were used and the results obtained from these methods were found to support each other. Key words: DNA damage, comet, comet assay, fluorescence micronukleus, micronucleus, UV radiation, UVA, genotoxicity