Pharmacological Applications of Phlorotannins: A Comprehensive Review

Background: Seaweeds, including marine brown algae, are traditional food sources in Asia. Phlorotannins, as the product of the polyketide pathway, are mainly found in brown algae. Different properties have been attributed to this group of marine products ranging from antiallergic to anticancer activity. Mechanism of action is not obvious for all these properties, but there are some explanations for such effects. Objective: The current study aimed to review the phlorotannins and to assess the beneficial uses in medicine. Methods: Different databases were explored with the exact terms “Phlorotannin”, “Seaweed” and “Brown Algae”. Data assembly was finalized by June 2019. The papers showing the effects of phlorotannins in medicine were gathered and evaluated for further assessment. Results: General physiological aspects of phlorotannins were firstly evaluated. Different arrays of pharmacological properties ranging from anti-diabetic activity to cancer treatment were found. The mechanism of action for some of these beneficiary properties has been confirmed through rigorous examinations, but there are some features with unknown mechanisms. Conclusion: Phlorotannins are characterized as a multifunctional group of natural products. Potential antioxidant characteristics could be attributed to preventive and/or their curative role in various diseases.