Comparison of Cytotoxic, Genotoxic, and DNA-Protective Effects of Skyrin on Cancerous vs. Non-Cancerous Human Cells

Secondary metabolites as a potential source of anticancer therapeutics have been the subject of many studies. Since hypericin, a metabolite isolated from L., shows several biomedical properties applicable in oncology, the aim of our study was to investigate its potential precursor skyrin in terms of genotoxic and DNA-protective effects. These skyrin effects were analyzed by cell-free methods, and cytotoxicity was estimated by an MTT assay and by a trypan blue exclusion test, while the genotoxic/antigenotoxic potential was examined by comet assay using non-cancerous human lymphocytes and the HepG2 cancer cell line. Skyrin did not show DNA-damaging effects but rather exhibited DNA-protectivity using a DNA-topology assay. However, we observed only weak antioxidant and chelating skyrin properties in other cell-free methods. Regarding the cytotoxic activity of skyrin, HepG2 cells were more prone to skyrin-induced death in comparison to human lymphocytes. Skyrin in non-cytotoxic concentrations did not exhibit elevated genotoxicity in both cell types. On the other hand, skyrin displayed moderate DNA-protective effects that were more noticeable in the case of non-cancerous human lymphocytes. The potential genotoxic effects of skyrin were not observed, and its DNA-protective capacity was more prominent in non-cancerous cells. Therefore, skyrin might be a promising agent used in anticancer therapy.