Exploiting the Potential of Ankistrodesmus braunii Polysaccharides: In Vitro Antioxidant Activity and In Vivo Cutaneous Biocompatibility

Current demands for sustainable cosmetic sources containing naturally derived compounds have led to extensive research for promising microalgae strains for large-scale cultivation. Given the enormous variety of microalgae strains, as well as their diverse cosmetic potential, here, we cultivated Ankistrodesmus braunii in tubular photobioreactors to extract polysaccharides (PSs) aiming their incorporation into a dermocosmetic prototype gel. In vitro antioxidant activity was determined by the DPPH• (2,2-diphenyl-1-picrylhydrazyl) assay, and in vivo experiments were performed on participants, measuring skin superficial (SK) hydration and transepidermal water loss (TEWL) to determine cutaneous biocompatibility, i.e., the PS safety. A. braunii aqueous PS had superior performance through the DPPH• test, thus, it was incorporated in a gel sample, and its safety profile was established by the cutaneous biocompatibility assay. The biocompatibility of the samples was confirmed by the SK hydration and TEWL results, which were not affected after the application of the gels. Our results suggested not only the biocompatibility of the microalgae PS dermocosmetic, but also the in vitro antioxidant potential, confirming the viability of this material as a new ingredient in cosmetic formulations.