Atividades biológicas de extratos e frações da macroalga marinha vermelha Hypnea pseudomusciformis (Nauer, Cassano & Oliveira)

Abstract

This study aimed to investigate the biotechnological potential of the red marine macroalga Hypnea pseudomusciformis, collected from Pacheco Beach, Caucaia, Ceará, Brazil. Extracts and fractions were analyzed to evaluate their biological activities, toxicity, and application in edible films. The algal biomass was subjected to sequential extraction using solvents of increasing polarity (hexane, ethyl acetate, and methanol), in addition to the extraction of sulfated polysaccharides. Subsequently, the extracts were fractionated by liquid-liquid partitioning and analyzed by thin-layer chromatography, leading to the preliminary characterization of the present secondary metabolites. The contents of total phenolic compounds and flavonoids were quantified, and the antioxidant activities were evaluated by the DPPH and ABTS+ free radical scavenging methods, ferrous ion chelating power (FIC), ferric ion reducing power (FRAP), and -carotene bleaching inhibition. The obtained fractions were also subjected to toxicological assays against seeds of improved Aodai cucumber (Cucumis sativus), Artemia sp. nauplii, and zebrafish (Danio rerio), evaluating possible phytotoxic and/or cytotoxic effects. Additionally, the incorporation of the fractions into carrageenan-based edible films was investigated, evaluating physicochemical properties such as water vapor permeability, thickness, solubility, and colorimetric parameters. The results demonstrated that the extracts and fractions contained different chemical profiles and biological activities, highlighting the influence of solvent polarity on the extraction of bioactive compounds. The variable antioxidant capacity of algal extracts, across different assays, showed their potential for application as a natural source of antioxidants. In toxicological tests, the response depended on the concentration, with greater toxicity at higher concentrations, especially for the hexane fraction. The edible films incorporated with the fractions showed alterations in physical and colorimetric properties, demonstrating potential for application in biodegradable packaging systems with functional potential. Thus, the results obtained show that H. pseudomusciformis constitutes a promising source of bioactive compounds with potential application in the pharmaceutical, food, and biotechnological fields.