The extract of Chlorella vulgaris exerts protective effects against ultraviolet B radiation-induced damages in human dermal fibroblasts = Chlorella vulgaris 미세조류 추출물의 자외선B 의존적 인간 진피섬유아 세포 손상에 대한 보호 효능

Abstract

Ultraviolet B (UVB) radiation accelerates skin aging by inducing direct DNA damage and indirect intracellular damage, which induce cell cycle arrest and apoptosis in human dermal fibroblasts (NHDFs). In this study, we demonstrated that pretreatment with the hexane extract of Chlorella vulgaris microalgae protects UVBmediated cell damages in NHDFs. Firstly, we compared the cytotoxicity effect of four extracts (ethanol, hexane, ethyl acetate and distilled water) of Chlorella vulgaris on NHDFs, and found that the four extracts had a little cytotoxicity at 1-20 μg/ml. Additional biochemical assay showed that UVB-induced cytotoxicity was significantly reduced in NHDFs posttreated with only hexane extract of Chlorella vulgaris. Furthermore, to increase the UVB-protection effect of the extract, we changed the concentration and treatment time, and found that 48 h of posttreatment with hexane extract (20 μg/ml) of Chlorella vulgaris significantly increased the cell viability by 34.01±5.86% compared with the viability of UVB-irradiated NHDFs. In addition, we found that the hexane extract of Chlorella vulgaris promoted the DNA repair properties in NHDFs, as revealed by luciferase-based DNA repairing assay. Overall, our results indicate that hexane extract of Chlorella vulgaris is implicated as a potential chemopreventive agent through UVB protection effect on NHDFs.