Extracts and bioactives from microalgae (sensu stricto): Opportunities and challenges for a new generation of cosmetics

Abstract

The cosmetic industry, which increasingly aims to develop products that affect body appearance, prevent aging and promote skin and hair well-being, has changed over the last decades. The increased sensibility of consumers to the ethics of green economy drew the attention of this industry to microalgae as novel source of active ingredients. Microalgae, which are often improperly considered as inclusive of prokaryotic microorganisms, i.e. cyanobacteria, are eukaryotic microorganisms capable of synthesising biologically active molecules that affect human metabolism. Many classes of beneficial compounds, including carotenoids, polyphenols, vitamins and polysaccharides, can be obtained from microalgae cultivated with sustainable and environment-friendly techniques. Microalgal extracts are already commercialised in products that claim several biological activities, such as hair growth stimulation, prevention of solar radiation damages, modulation of skin pigmentation, skin tightening and anti-aging. However, their mechanisms of action and metabolic effects are not fully understood, and the related beneficial effects are probably underestimated. This contribution aims to review the state-of-the-art cosmetic applications of microalgae with a critical discussion of the experimental methods adopted and potential perspectives.