The antioxidant biomolecules of marine algae

The control of oxidative stress represents a major public health issue, particularly in the context of demographic aging. This phenomenon corresponds to an imbalance between the production of free radicals – unstable molecules generated by cellular metabolism – and the body’s defense capacities, such as antioxidants, responsible for neutralizing them. When it becomes persistent, this imbalance can damage cells. Thus, antioxidants are today privileged targets to prevent cellular damage associated with aging and various pathologies, notably cancers. In the face of these challenges, researchers are interested in natural antioxidant molecules, particularly those derived from marine macroalgae.

Seaweeds – brown, red, or green – are a remarkable source of antioxidant biomolecules. Living in often extreme environments (UV, salinity), macroalgae produce bioactive compounds such as polyphenols and carotenoids that have strong antioxidant properties with potential applications in cosmetics, nutraceuticals, and pharmaceuticals.

At the EBI, a team of researchers is also studying mycosporine-like amino acids (MAAs) extracted from red algae, Porphyra umbilicalis and Palmaria palmata, and from brown algae, Padina pavonica, in collaboration with the Lebanese University. MAAs constitute a family of more than 40 hydrophilic molecules of low molecular weight <00Da) characterized by a cyclohexenone core substituted with one or two amino acids. Initially involved in photosynthesis, these molecules have evolved to play a role in photoprotection against UV radiation.

The MAAs studied at the EBI are extracted using an eco-friendly solid-liquid process that meets the requirements of the cosmetic industry. The obtained extracts, enriched in MAAs, demonstrate photoprotective properties on human cells, as well as direct antioxidant activity by trapping reactive oxygen species and indirect activity by inhibiting their formation. These extracts are promising candidates for the development of bio-inspired cosmetic products that are both environmentally friendly and potentially less cytotoxic than synthetic compounds.

Your contacts: Hélène Di Martino, Saad Saba