Protective Effect of brown seaweeds on UVB-induced Oxidative Stress, in vitro and in vivo zebrafish model

Abstract

Chronic exposure of the skin to ultraviolet B (UVB) radiation induces oxidative stress, which plays a crucial role in the induction of skin aging. In this study, the protective effect of extracts of the brown seaweed Ecklonia cava on UVB radiation-induced oxidative stress was assessed in viability tests measuring the intracellular fluorescence of dichlorofluorescein diacetate and colorimetric reduction of 3-(4,5-dimethylthiazol-yl)-2,5-diphenyltetrazolium bromide, and Hoechst 33342/propidium iodide staining of apoptosis activity. E. cava extracts evidenced a profound effect against UVB radiation-induced oxidative stress. The highest activity was produced by the 100% methanol extract. Partitioning of the methanol extract with different organic solvents revealed a pronounced protective effect in the ethyl acetate fraction. The isolated active compounds were phlorotannins, especially dieckol, as identified using ultraperformance liquid chromatography-tandem mass spectrometry. Among the phlorotannins, dieckol showed a higher protective effect than the other phlorotannins. Therefore, UVB protection of dieckol was evaluated via DCFH-DA, DAF-FM DA, acridine orange and morphological changes in zebrafish. Hence, these results indicated that dieckol has potential protective effects on UVB-induced cell death, which might be useful in antioxidant and cosmetic formulations.