Study on the bioactive activities of fucoidan extracted from brown macroalgae (Sargassum flavicans) collected in Hon Son Island, Vietnam

The pharmaceutical industry now recognizes the world's oceans as a crucial source for medical research, teeming with organisms possessing unique biological properties. Researchers have successfully extracted bioactive compounds from marine life, especially the extract of brown algae demonstrated various modes of action, including antiproliferative, antioxidant, and antimicrobial effects. This study aims to evaluate in vitro antioxidant, antibacterial, antifungal, cytotoxic, and enzymatic inhibitory properties of fucoidan extracted from Sargassum flavicans at Hon Son island, Vietnam. Specifically, the infrared spectroscopy spectra showed that the fucoidan, extracted using the HCl method, retained impurities that contained chlorine radicals in their molecular structure. The results of the 2,2-Diphenyl-1-Picrylhydrazyl assay indicated that the algal extract was capable of scavenging free radicals with the IC50 value of the brown algae extract was 206.21 ± 0.695 μg/ml. In addition, the algal extract displayed potential inhibition of α-amylase activity with an IC50 value of 10.87 ± 0.25 μg/ml. Moreover, the algal extract revealed weak activity against Hela cell line. Regarding antimicrobial activities, the results indicated that the extract had potential effects against Escherchia coli, Bacillus cereus, and Cadida albicans. Briefly, these present findings showed that fucoidan extract from S. flavicans can be considered as a new natural resource, and discovering and utilizing this resource can lead to improvements in both health and economic prosperity.