Effect of Lycium barbarum polysaccharide on expression of vascular endothelial growth factor and hypoxia inducible factor-1α in ultraviolet B-radiated HaCaT cells

Abstract

Objective To evaluate effects of Lycium barbarum polysaccharide (LBP) on expression of vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α (HIF-1α) in ultraviolet B (UVB) -radiated HaCaT cells. Methods Conventionally cultured HaCaT cells were divided into control group and LBP groups, which were firstly treated with DMEM, 12.5, 25.0, 50.0 and 100 μg/ml LBP solution respectively for 4 hours, and then were irradiated by UVB at different intensity of 0, 20, 40, 60 mJ/cm2 separately. After 24-hour continuing culture, CCK-8 assay was performed to determine the cell survival rate, and an enzymatic-biochemical method to estimate the activity of superoxide dismutase (SOD) . RT-PCR and Western blot analysis were conducted to measure the mRNA and protein expression of HIF-1α and VEGF respectively. Results Compared with the control group at the same UVB radiation dose, the 12.5-, 25.0-and 100.0-μg/ml LBP groups showed different extents of increase in survival rates of UVB-radiated cells (P < 0.05) , and the 50.0-μg/ml LBP group showed the highest cell survival rate (P < 0.01) . Among all the LBP groups, SOD activity was highest in the 50.0-μg/ml LBP group (P < 0.01) . Along with the increase of UVB radiation dose, the mRNA and protein expression of HIF-1α and VEGF all gradually increased. Compared with the control group, the 50.0-μg/ml LBP group could effectively reduce the mRNA and protein expression of HIF-1α and VEGF in HaCaT cells (all P < 0.05) . Conclusion LBP may play a role in protecting cells from UVB radiation-mediated damage, likely by influencing the mRNA and protein expression of HIF-1α and VEGF in HaCaT cells. Key words: Ultraviolet rays; Lycium barbarum; Polysaccharides; Endothelial growth factors; Hypoxia inducible factor 1α; HaCaT cells