The protective effects of 6-CySeCD with GPx activity against UVB-induced injury in HaCaT cells

The generation of harmful reactive oxygen species (ROS) induced by UVB irradiation could induce cell apoptosis and change the cell cycle. 6A,6A'-dicyclohexylamine-6B,6B'-diselenide-bis-β-cyclodextrin (6-CySeCD) is a novel glutathione peroxidase (GPx; EC 1.11.1.9) mimic. The aim of this study was to investigate the anti-oxidative effects of 6-CySeCD in cultured immortalised human keratinocyte cells (HaCaT).

HaCaT cells were treated with 30 mJ/cm(2) UVB to establish a damage model. The cultured HaCaT cells were randomly assigned to the control, UVB and treatment groups. The treatment group was incubated with 20 μmol/L of GPx mimics before UVB irradiation. Cell viability was detected by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the level of lipid peroxidation was determined by the formation of malondialdehyde (MDA), DNA fragmentation was observed using agarose gel electrophoresis and the levels of intracellular ROS and cell cycle progression were measured by flow cytometry.

The levels of cytotoxicity, intracellular ROS, lipid peroxidation and oxidative DNA damage significantly increased after UVB irradiation in the HaCaT cells. UVB irradiation caused pre-G1 -phase arrest in HaCaT cells and significantly reduced the number of HaCaT cells in the S phase. The GPx mimics 6-CySeCD and 2-phenyl-l,2-benzisoselenazol-3(2H)-one (ebselen) significantly blocked UVB-induced apoptosis and changed the cell cycle of the HaCaT cells. The blocked effect of pretreatment 6-CySeCD in UVB-irradiated HaCaT cells was better than that of pretreatment with ebselen.

6-CySeCD can relieve the damage induced by UVB irradiation in HaCaT cells.