Antimicrobial and cytotoxic activities of marine plants and invertebrates from the coast of Espirito Santo in Vanuatu

Marine invertebrates and algae collected off the coast of Espirito Santo in Vanuatu were investigated for antimicrobial and cytotoxic activities. The combined crude methanol-dichloromethane extracts from 52 sponges, 5 algae, 17 soft corals (cnidaria) and 5 other samples of various marine invertebrates were screened for cytotoxicity, antibacterial and antifungal properties. The cytotoxicity of the samples was determined using a brine shrimp lethality test and, notably, 78% of the invertebrate and algae samples showed cytotoxic activity against brine shrimps with the sponge Crella spinulata displaying the strongest activity. Antimicrobial activity was determined against three resistant bacterial strains and two fungal strains. A total of 42% of the samples tested showed antimicrobial activity against at least one of the five strains. The most potent antibacterial activities were recorded for the sponges Lamellodysidea herbacea, Phyllospongia sp., a sponge in the order Halichondrida and Hippospongia metachromia. A Theonella sp. sponge displayed the strongest antifungal activity.