Microalgae Photo-Protectants and Related Bio-Carriers Loaded with Bioactive Entities for Skin Applications-An Insight of Microalgae Biotechnology.

Microalgae are photosynthetic organisms known for producing valuable metabolites under different conditions such as extreme temperatures, high salinity, osmotic pressure, and ultraviolet radiation. In recent years, these metabolites have become a trend due to their versatility in applications such as pharmaceuticals, cosmetics, and others. They have even been proposed as an alternative source of bioactive metabolites to avoid the harmful effects on the environment produced by active compounds such as oxybenzone in commercials sunscreens. One of the most studied applications is the use of microalgae for skin care and topical use as cosmeceuticals. With the increasing demand for more environmentally friendly products in cosmetics, microalgae have been further explored in relation to this application. It has been shown that some microalgae are resistant to UV rays due to certain compounds such as mycosporine-like amino acids, sporopollenin, scytonemin, and others. These compounds have different mechanisms of action to mitigate UV damage induced. Still, they all have been proven to confer UV tolerance to microalgae with an absorbance spectrum like the one in conventional sunscreens. This review focuses on the use of these microalgae compounds obtained by UV stimulation and takes advantage of their natural UV-resistant characteristics to potentially apply them as an alternative for UV protection products.