Protective effect of the brown seaweed Padina boryana against UVB-induced photoaging in vitro in skin cells and in vivo in zebrafish

The ethanol extract of Padina boryana (PB-EtOH) containing phlorotannin effectively inhibits oxidative stress and melanin synthesis, suggesting the potential use of PB-EtOH in the cosmetics industry. To further investigate the cosmetic effects of PB-EtOH, its photoprotective effects against ultraviolet (UV) irradiation was investigated. The results displayed that PB-EtOH remarkably improved cell viability by suppressing the apoptosis via cleaning the intracellular reactive oxygen species (ROS) in UVB-exposed human keratinocytes. In addition, PB-EtOH effectively suppressed oxidative stress, increased collagen synthesis, and reduced the matrix metalloproteinase production in UVB-exposed human dermal fibroblasts in a concentration-dependent manner. Furthermore, the in vivo anti-photoaging effect was determined using the zebrafish model. The results displayed that PB-EtOH remarkably attenuated UVB-stimulated photodamage. The photoprotective effect was displays in reducing the levels of ROS, nitric oxide, lipid peroxidation, and cell death. These results demonstrate that PB-EtOH possesses anti-photoaging effects and suggest that PB-EtOH may be an ideal ingredient to develop a skincare product in the cosmetic industry.