Analysis of Bioactive Compounds in Some Marine Seaweeds along the Coastline of Bandar Abbas, Iran

Applications of seaweeds as food ingredients and bioactive compounds are increasing these days. Many of seaweeds have to be evaluated for these purposes. This study investigated the biological activities of organic extracts of four green and a red macroalgae collected from the coast of Bandar Abbas, Iran. After species identification, the bioactivities of seaweeds have been studied by antioxidant assay (Ferric reducing power and total antioxidant capacity), total phenolic and flavonoid contents, antibacterial activity, and brine shrimp cytotoxicity activity on model organism, Artemia salina (Linnaeus, 1758) and Artemia franciscana (Kellogg, 1906) were anaysed. The results revealed the most effective algal extracts by maximum antioxidant capacity were recorded using methanol extracts of Ulva intestinalis Linnaeus 1753, and Ulva clathrata (Roth) C. Agardh 1811. In addition, the highest content of total phenolic content was recorded by green seaweeds. While, the highest flavonoid content was obtained from Gracilariopsis persica Bellorin, Sohrabipour & E.C. Oliveira. Most extracts showed significant antibacterial effects, with disk diffusion method. Among the various extracts, the n-hexane extract was found the highest zone of inhibition against analyzed pathogenic bacteria. U. intestinalis and U. clathrate have a better antimicrobial activity and are a potential source of antimicrobial compounds. Further, we found a best toxic effect to A. salina in n-hexane extract of G. persica, LC50 =125 μg/ml. Generally, the findings can be introduced the green seaweeds as priority species for biological properties and can be subject of isolation of the natural antimicrobials.