Alla I. Potapovich ^a, Tatyana V. Kostyuk ^a, Tatsiana G. Shutova ^b, Vladimir A. Kostyuk^a*

^a Byelorussian state university, Niezaližnasci Avenue, 4, 220030, Minsk, Belarus

^bInstitute of Chemistry of New Materials, National Academy of Sciences of Belarus, Skaryny Street, Minsk 220141, Belarus 

The antiradical activity of flavonoids in simple biochemical systems was discovered more than 30 years ago [1]. Subsequently, the antioxidant and anti-inflammatory effects of flavonoids were demonstrated in human cells upon exposure to various inflammatory stimuli [2, 3]. However, despite their numerous biological activities, the clinical use of flavonoids is limited mainly due to their low water solubility, which results in poor cellular uptake and poor permeability of flavonoids through the skin. To overcome these limitations, potential drug molecules can be incorporated into liposomes or polymer nanoparticles, which have great potential as drug carriers [4]. In this work, we evaluated the cellular effects of native and microstructured flavonoids. Microcrystals of quercetin and resveratrol coated with (polyallylamine hydrochloride/sodium polystyrenesulfonate)₄ or (chitosan/dextran sulfate)₄ shells were prepared by layer-by-layer assembly. Cultured human HaCaT keratinocytes were exposed to UV-C, after which the cells were incubated with native and microstructured flavonoids. Phosphorylation of histones H2AX, DNA damage, cell viability and integrity were assessed. The data obtained indicate that native and microstructured flavonoids added immediately after exposure to UV-C increased cell viability in a dose-dependent manner, however, the effectiveness of microstructured quercetin was more pronounced than that of the native compound. It has been shown that flavonoids can activate the process of repairing genetic damage, while the coated quercetin (chitosan/dextran sulfate)₄ was more effective than the native compound in reducing the amount of DNA damage in the nuclei of keratinocytes exposed to UV-C radiation.