Anti-skin Aging Potential of Sargassum thunbergii Ethanolic Extract: Antioxidant, Anti-inflammatory, and Antiwrinkle Effects on L929 Fibroblast Cells

Abstract

Increasing life expectancy of the human population has created a demand for functional food with anti-skin aging properties. Skin aging is a degenerative process caused by oxidative stress, inflammation, and matrix destruction. Some secondary metabolites isolated from marine macroalgae have been shown to exhibit potential dermatological benefits. The present study investigated the skin-protective properties of the ethanolic extract from Sargassum thunbergii (STEE) via antioxidant, anti-inflammatory, and antiwrinkle effects on mouse fibroblast L929 cells. The optimal extraction conditions for STEE were determined as follows: ratio of liquid to solid 25 : 1 mL/g, concentration of ethanol 40.2%, and extraction time 40 min. STEE was further purified by adsorption using a macroporous resin, SP700. STEE exhibited high DPPH radical and hydroxyl scavenging activity in vitro, enhanced the viability of H2O2-treated L929 cells, and reduced intracellular ROS generation in a dose-dependent manner. Superoxide dismutase and glutathione peroxidase activities and total antioxidant capacity in H2O2-treated L929 cells were increased while malondialdehyde content was markedly reduced by pretreatment with STEE. The inhibitory effect of STEE on H2O2-induced inflammation was shown by the downregulation of tumor necrosis factor-α, interleukin-6, cyclooxygenase-2, and inducible nitric oxide synthase. Furthermore, STEE reduced the matrix metalloproteinase-2 expression and inhibited collagenase and elastase activities. Moreover, STEE was nonirritating to human skin at 100 mg/mL according to the in vitro skin irritation test using EpiSkin™. Hemolysis assay showed that the hemolysis EC50 (1275 μg/mL) of STEE is much higher than the maximum effective concentration (125 μg/mL) against H2O2 exposure. Our results demonstrate that STEE may be a good candidate for the development of anti-skin aging functional food and cosmetic products.