Antioxidant Activity and Protective Effect of Pyropia haitanensis Extract Against UVB-induced Photodamage

Abstract:

[Objective] This study aimed to investigate the antioxidant effects of Porphyra haitanensis extract (PHE) and its protective effect against UVB-induced photodamage in microbial models and human immortalized keratinocytes (HaCaT). [Method] The components of PHE were analyzed, and the antioxidant activity of PHE was evaluated by DPPH and hydroxyl radical scavenging assays. Microbial models were used to investigate the protective effects of PHE against UVB irradiation-induced damage in Escherichia coli (E. coli) and Candida albicans (C. albicans). Additionally, the HaCaT cell model was employed to analyze how PHE alleviated UVB-induced expression of oxidative stress factors and DNA damage. [Result] The primary components of PHE were carbohydrates, with a mass fraction of (639.82±17.35) mg/g. PHE demonstrated good in vitro antioxidant activity and effectively enhanced the radiation resistance rates of both E. coli and C. albicans. At a mass concentration of 1.00 mg/mL, PHE increased the HaCaT cell survival rate (P<0.01) and reduced the intracellular reactive oxygen species (ROS) level to 29.52% (P<0.001), thereby alleviating oxidative stress damage. In addition, it decreased the mass concentration of cyclobutane pyrimidine dimers (CPDs) to 7.66 mg/mL (P<0.005). [Conclusion] PHE may exert the protective effect against photodamage by balancing the intracellular oxidative stress system and mitigating DNA damage.