Antioxidant and antifungal activity of red seaweed Laurencia sp

Abstract

Marine macroalgae contain bioactive compounds and can produce a great variety of secondary metabolites useful for human health. Laurencia is a genus of red algae that grow in temperate and tropical shore areas, in littoral to sublittoral habitats, at depths up to 65 m. The marine red algae Laurencia sp. was collected in Žukovica, coast of Montenegro (the Adriatic Sea) during August 2022. Water, 70% ethanolic, 96% ethanolic and methanolic extracts of Laurencia sp. were prepared and tested for antioxidant and antifungal activity. Antioxidant potential was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. The extracts tested showed significant antioxidant potential which varied depending on the solvent used for extraction. The highest antioxidant activity was found for 70% ethanolic extracts, with EC50 values of 2.71 μg/ mL. Antifungal activity of extracts was evaluated against Aspergillus parasiticus, A.destruens, Cladosporium crousii, Mucor hiemalis, Mortierella alpina, Fusarium oxysporum, Geosmithia ulmacea and Penicillium roseopurpureum by a serial dilution technique with a tested range of concentrations from 10 to 0.039 mg/mL. Extracts demonstrated no antifungal activity in the tested range of concentrations. Results reviled potential of Laurencia extracts as promising natural source of antioxidative activity. Further researches should be focused on detailed chemical analysis of extracts and differential testing of specific components as carriers of antioxidative activity.