Brazilian Beach-Cast Seaweeds: Antioxidant, Photoprotection and Cytotoxicity Properties

The potential of seaweed extracts in cosmetic applications have increased with novel development and market. Beneficial biological properties include the ability to struggle aging and anticancer agents. This research aimed to evaluate antioxidant, photoprotective and cytotoxic properties of extracts from beach-cast seaweed species from the Brazilian coast in order to propose an appropriate use of this sustainable resource. Analysis of antioxidant capacity, UV/VIS absorption, quantification of UV photoprotectors, total content of C, N and S, development of cosmetic creams and evaluation of the cytotoxicity activity against tumoral cells lines were performed. The highest antioxidant capacity was found in extracts of brown seaweeds, followed by red seaweeds, with the lowest activity detected in the green seaweed. Same pattern was observed for phenolic compounds. The extracts did not show cytotoxicity activity against healthy human cells. Other forms of extraction and incorporation of the extract into the base creams should be evaluated, the isolation and purification of substances could increase the efficiency of the photoprotective capacity. The species were highly promising and proved to be natural sources of antioxidants and substances with cytotoxicity activity against tumoral cells; therefore, they could be exploited as functional ingredients with specific applications for different types of industries. The application of seaweed extracts in combination with other natural ingredients can help in the design of new cosmetics against the negative effects of UV radiation, in addition to having the great advantage of not presenting toxicity to health or the environment because they are biodegradable. Graphical Abstract