Evaluation of the content and bioactivity of four macroalgae species from the Persian Gulf

Macroalgae are rich in diverse valuable compounds so they are known as the 21 century medicinal plants. In this study polar to nonpolar extracts of four macroalgae species, Sargassum boveanum, Fucus trinodis, Galaxaura rugos and Laurencia denderoidea were collected from the Persian Gulf coastlines, evaluated for their phenol and flavonoid contents and antioxidant and antibacterial activities.

Phenol and flavonoid contents of species were estimated by Folin-Ciocalteu and Aluminum chloride methods, respectively. Antioxidant activities of extractions were analyzed by total antioxidant activity (TAC) and reducing power of Fe3+ respectively and also antibacterial activity of samples were analyzed by disc diffusion method against two gram positive and two gram negative bacteria.

F. trinodis showed the highest phenolic (1.38 gGA/100gDW.) and flavonoid (0.798 gQE/100gDW.) contents and G. rugosa showed the lowest phenolic (0.240 gGA/100gDW.) and flavonoid (0.094 gQE/100gDW.) contents. Chloroform extract of F. trinodis (2.98 ugASA/mg) and S. boveanum (2.48 nm) showed the maximum level of TAC and reducing power antioxidant activities, respectively. The samples with high content of phenolic and flavonoid contents showed the highest antioxidant activity too. All the three extracts of S. boveanum and F. trinodis showed the considerable antibacterial activity against all the four examined strains of bacteria especially negative gram bacteria.

The studied macroalgal species showed considerable phenolic content and bioactivities suggest that they can be suitable for medical and medicinal applications.