Estudo toxicológico de extratos do coral alcionáceo Chromonephthea braziliensis (Alcyonacea, Nephtheidae)

Abstract

Coral reefs are diverse ecosystems that have a high density of biodiversity leading to intense competition among species. These species may produce unknown substances, many with pharmacological value. Chromonephthea braziliensis is an invasive soft coral from the Indo-Pacific Ocean that has been possibly transported by oil platforms and whose presence can be a threat to Arraial do Cabo region s biodiversity. This species produces secondary metabolites that are responsible for inducing damage to the local ecosystem. The purpose of this study is the search of new drugs for generally chemotherapy based on the structure of bioactive compounds. Coral extracts were prepared from dried colonies (solvents: hexane, dichloromethane, ethyl acetate, and methanol). Chemical analyses were performed to characterize the extracts and evaluated their cytotoxic and mutagenic activities, using the bacterial reverse mutation assay (Salmonella/microsome) with TA97 strains, TA98, TA100 and TA102; genotoxic activity, using DNA breakage analysis and micronucleus formation and; toxic effects for nauplii microcrustaceans. Cytotoxicity was observed in the presence of S9 mix for dichloromethane extract for strain TA102 at the 20 µg/plate concentration and methanol extract for TA97 at 5 and 20 µg/plate. The dichloromethane, ethyl acetate and methanol extracts present genotoxicity for plasmidial DNA at high concentrations (250 µg/mL), but no DNA damage was observed in micronucleus assay. All extracts were toxic for nauplii microcrustaceans at least one of tested concentrations (0.01 1000 µg/mL), but LC50 was calculated only for the hexane, dichloromethane and ethyl acetate extracts.