关键词: 坛紫菜多酚, 抗氧化, 紫外线B, 氧化应激

Abstract: In the present study, polyphenols from Porphyra haitanensis (PP) were extracted and separated, and their in vitro antioxidant activity was investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, the ability to inhibit the color fading of β-carotene and ferric reducing antioxidant power (FRAP), as well as their protective effect against oxidative damage induced by ultraviolet radiation B (UVB) in human skin fibroblast cells (HSFs). The aim of this investigation was to ascertain the applicability of PP to protect the skin against UV damage. In vitro tests demonstrated that PP had strong antioxidant activity, whose DPPH radical scavenging capacity was equivalent to that of BHT at the same concentration but whose ability to inhibit the color fading of β-carotene in the presence of linoleic acid and FRAP were weaker. The cellular experiment showed that PP significantly reduced lactic dehydrogenase (LDH) leakage from HSFs induced by UVB irradiation, maintained cell membrane integrity, decreased reactive oxygen species (ROS) level, enhanced the activity of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx), therefore attenuating cellular oxidative stress, enhancing the oxidative stress resistance of endothelial cells and significantly inhibiting the apoptosis of HSFs. These findings led us to conclude that PP can protect HSFs against UVB-induced oxidative damage and has potential for protection against UV-induced skin damage.

Key words: Porphyra haitanensis polyphenol, antioxidant, ultraviolet radiation B (UVB), oxidative stress