Skin cells protection against UVA radiation – The comparison of various antioxidants and viability tests

This study compares the effects of vitamins - including ascorbic acid, its derivative 3-O-ethyl-ascorbic acid (EAA), and tocopherol - as well as the main non-psychoactive phytocannabinoids on the viability of various skin cells, including healthy (keratinocytes/melanocytes/fibroblasts) and cancer cells (melanoma/SCC), under standard culture conditions and after the exposure to UVA radiation. All the conducted tests (MTT, SRB, and LDH) consistently indicate that the regenerative effect of EAA is stronger than that of ascorbic acid, while tocopherol acts selectively on healthy/cancer cells, inducing or inhibiting their proliferation, respectively. In the case of phytocannabinoids, only cannabidiol shows protective/regenerative properties for healthy cells. Moreover, the response of melanocytes to cannabigerol is divergent; however, only the LDH test indicates that cannabigerol strongly increases the membrane permeability of those cells. In summary it should be emphasized that various tests may give partially divergent results due to a variety of measured parameters. Nevertheless, despite the positive viability test results for the potential protective compound, caution should be taken as it may promote healthy skin cells but also protect cancer cells.