Protective effects of an extract of the freshwater microalga Scenedesmus rubescens on UV‐irradiated skin cells

Background Skin ageing results from intrinsic but also extrinsic factors of which UV irradiation is a main cause. It is hence of interest to have means to protect skin from UV irradiation-induced damage. We selected an extract of the freshwater microalga Scenedesmus rubescens and assessed its potential to protect skin from photoageing caused by UV irradiation. Methods Skin cells in vitro and ex vivo were analysed for markers of UV irradiation-induced photodamage such as decreased viability, decreased collagen content, hyperpigmentation and sunburn cells. Results We found that a dry extract of the microalga Scenedesmus rubescens was able to suppress cellular signs of ageing induced by UV irradiation. It enhanced dermal fibroblast viability, rescued dermal collagen content, inhibited the formation of sunburn cells and inhibited tyrosinase activity. Conclusion An extract of Scenedesmus rubescens showed broad activity against markers of UV irradiation-induced cutaneous ageing. It may therefore be used as a preventive or regenerative agent for anti-ageing strategies.