Avaliação do potencial antimicrobiano e citotóxico do extrato aquoso da esponja marinha Aplysina lactuca

Abstract

Marine biodiversity harbors organisms adapted to extreme conditions, capable of producing bioactive compounds with unique chemical structures. Marine sponges, which are part of the Porifera phylum, are known for synthesizing metabolites with antibacterial, antiviral, antifungal, and antitumor properties in response to the stress of their sessile, filter-feeding lifestyle. Considering the growing threat of antimicrobial resistance, which compromises the effectiveness of conventional treatments, the search for new bioactive compounds is urgent. In this scenario, marine ecosystems emerge as promising sources for the development of new drugs. This study aimed to evaluate the antibacterial potential of the aqueous extract of the marine sponge Aplysina lactuca against standard-sensitive and resistant strains of Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis, as well as to evaluate the extract's cytotoxic potential against erythrocytes and nauplii of Artemia sp. The compounds were extracted with distilled water. The extract was then concentrated by lyophilization and subjected to antibiogram testing at different concentrations (20 to 0.625 mg.mL-1), observing the diameter of the inhibition zones. The extract was also subjected to cytotoxicity tests against the Artemia sp. nauplii model. Furthermore, the extract's hemagglutinating and hemolytic activity were evaluated. The A. lactuca extract showed bactericidal effects at concentrations above 5 mg.mL-1, cytotoxicity at concentrations above 5 mg.mL-1 at room temperature, and low lethality with the heated extract. Furthermore, dose-dependent hemagglutinating activity and a hemolytic rate ranging from 8.7 to 22.3% were observed. Therefore, this study presents promising findings that can serve as a basis for future research aimed at isolating the bioactive compounds present in these organisms.