DNA damage protecting and free radical scavenging properties of mycosporine-2-glycine from the Dead Sea cyanobacterium in A375 human melanoma cell lines

Abstract

Mycosporine-like amino acids (MAAs) are a group of natural sunscreen compounds that possess highly photoprotective properties. The most commonly found MAAs in marine organisms is shinorine, porphyra-334, and mycosporine-glycine. However, the halophilic species accumulate mycosporine-2-glycine (M2G) as the major MAA. In this study, we have investigated the protective effect of M2G against oxidative stress. In vitro radical scavenging activity revealed that M2G exhibited a significant inhibition with scavenging concentration (SC) 50 value of 22±1.4μM. In vivo analysis using the human melanoma A375 and a control cell line (NHSF) showed that M2G at low concentration (i.e. micromolar range) protected the cells against the oxidative stress (H₂O₂)-induced cell death. Comet assay to assess total DNA strand breaks demonstrated that M2G was not genotoxic and protected against the DNA damage by H₂O₂ treatment at the same level as ascorbic acid. To our knowledge, this is the first evidence demonstrating potential protective role of the natural sunscreen compound M2G against oxidative stress-induced DNA damage in human cell lines. The potent antioxidant activity combined with DNA protection ability of M2G may support its endorsement as a potential natural sunscreen with antioxidant property. These findings provide important clues for possible use of M2G in pharmaceutical and biotechnological applications.