Biological activity of a polyphenolic complex of Arctic brown algae

One of the most significant groups of compounds that determine the pharmacological significance of Arctic brown algae is the polyphenols, namely phlorotannins. Brown algae of the family Fucaceae, growing in the waters of the Arctic seas, accumulate a large number of polyphenolic compounds. The pharmacological significance of plant polyphenols is related to their structure; however, it is worth noting that the relationship between the molecular weight and the biological activity of brown algae phlorotannins is still not well understood. Thus, the aim of this work was the isolation and characterization of the polyphenol fraction of the Arctic brown algae Fucus vesiculosus with the following evaluation of the radical scavenging, bacteriostatic, fungistatic, and phagocytic activities. The highest radical scavenging activity (700–900 mg of ascorbic acid g−1 of extract) has fractions whose composition is characterized by the predominance of oligomeric phlorotannins containing from 3 to 8 structural units of phloroglucinol in the range of 374–994 Da. The polyphenol fractions obtained exhibit bacteriostatic effects in 45–85% of the studied pathogenic bacterial cultures. The fungistatic effect reaches a maximum of 35%. The test samples do not possess immunosuppressive properties and do not inhibit the phagocytic activity of neutrophilic granulocytes of human blood.