Preservation effects of geniposidic acid on human keratinocytes (HaCaT) against UVB

摘要

Geniposidic acid is a natural compound affiliated with iridoid glycoside which is contained in various plants such as Gardenia seeds, Eucommia bark, and Psyllium, and it is known that it has such effects as anti-inflammation, anti-virus, anti-cancer, anti-oxidation, suppression of stress, improvement of immune system, and relief of liver injury. However, there is a lack of research on action of geniposidic acid in dermal cells, so this research verifies effects of geniposidic acid on preservation of human keratinocytes, anti-oxidation, and DNA repair and finds out its mechanism. This study demonstrated feasibility of geniposidic acid on cosmeceutical application via ultraviolet (UV) B-induced damage protective effects such as oxidative stress reduction, DNA repair, and decrease of apoptotic cell death. To investigate cytotoxicity of angelic acid and proliferation influence, researchers used formazan detection by water-soluble tetrazolium salts (WST). To examine cell cycle distribution and sub-G1 portion, fluorescence-activated cell sorting (FACS) analysis was used to the experiment. For further investigation, cleaved caspase-3 levels were determined in apoptotic cell death analysis. And we conducted comet assay, in vitro anti-oxidant effects using radical scavenging assay, lipid peroxidation analysis, and mRNA expression analysis. Geniposidic acid protects UVB-induced cytotoxic damage and reduces apoptotic cell death caused by UVB in human keratinocytes (HaCaT). Also, this research finds out that geniposidic acid decreases formation of cleaved caspase-3 increase and reduces both tailed DNA and cyclobutane pyrimidine dimer (CPD) which is increased by UVB. Through radical scavenging assay, we demonstrate in vitro anti-oxidant effect of geniposidic acid and, via quantitative real-time polymerase chain reaction (qRT-PCR), find out that gene expression of superoxide dismutase 1 and 2 (SOD1 and SOD2) which are known as anti-oxidant gene increases dependently on concentration of geniposidic acid. Furthermore, geniposidic acid reduces lipid peroxidation to lead anti-oxidation effect. This research finds out that gene expression of XPC (XPC complex subunit, DNA damage recognition, and repair factor) and PCNA (proliferating cell nuclear antigen) which are DNA repair gene increases dependently on concentration of geniposidic acid. Through this research, we verify that geniposidic acid has effects on anti-oxidation and DNA repair in human HaCaT damaged by UVB and suggest that geniposidic acid as a cosmetic material is fully worthy to use to delay dermal cellular senescence by UVB effectively.