We report the first record of the sea anemone Anthopleura nigrescens on the Pacific coast of Central America. Five specimens from Mata Limón (Costa Rica) were collected from rocks of a man-made breakwater at sub-tidal level. Images of live specimens are presented. A map with its worldwide distribution is included and we concluded that this actiniarian can be considered widely distributed in the Indo-Pacific.

Actinoporins (APs) are soluble pore-forming proteins secreted by sea anemones that experience conformational changes originating in pores in the membranes that can lead to cell death. The processes involved in the binding and pore-formation of members of this protein family have been deeply examined in recent years; however, the intracellular responses to APs are only beginning to be understood. Unlike pore formers of bacterial origin, whose intracellular impact has been studied in more detail, currently, we only have knowledge of a few poorly integrated elements of the APs’ intracellular action. In this review, we present and discuss an updated landscape of the studies aimed at understanding the intracellular pathways triggered in response to APs attack with particular reference to sticholysin II, the most active isoform produced by the Caribbean Sea anemone Stichodactyla helianthus. To achieve this, we first describe the major alterations these cytolysins elicit on simpler cells, such as non-nucleated mammalian erythrocytes, and then onto more complex eukaryotic cells, including tumor cells. This understanding has provided the basis for the development of novel applications of sticholysins such as the construction of immunotoxins directed against undesirable cells, such as tumor cells, and the design of a cancer vaccine platform. These are among the most interesting potential uses for the members of this toxin family that have been carried out in our laboratory.

ObjectiveTo evaluate the antimicrobial and antifungal activities of the aqueous and partitioned extract of sea anemone Anthopleura nigrescens (A. nigrescens).MethodsThe sea anemone A. nigrescens was collected, minced, homogenized, lyophilized and then further partitioned with diethyl ether, acetone, ethanol and water. These fractions were evaluated for antimicrobial activity against bacterial and fungal pathogens.ResultsAcetone extract was found to produce a pronounced inhibition of 7.0 mm against Proteus vulgaris and diethyl ether extract inhibited Pseudomonas aeruginosa with an inhibition zone of 6.5 mm. In antifungal activity, ethanol extract showed good activity against Botrytis cinerea, Trichoderma harzianum and Rhizopus oryzae compared with other strains. Acetone and ethanol extract of A. nigrescens showed activity against all of pathogens tested. Slight activity was observed in the water extract with inhibition zone of 1.5 mm.ConclusionsThe present study revealed that sea anemone A. nigrescens may also contain some biologically active agents which have potential activity against pathogenic microorganisms

El filo Cnidaria incluye organismos considerados dentro de los más venenosos en la naturaleza. Más específicamente, alrededor de 32 especies de anémonas marinas han sido reportadas como productoras de péptidos y proteínas citolíticas. Este estudio fue llevado a cabo para evaluar la actividad hemolítica del extracto crudo de la anémona marina Aiptasia pallida en Costa Rica. El material biológico fue colectado, triturado, homogenizado y posteriormente centrifugado para la obtención del extracto crudo. El mismo fue caracterizado a través de una evaluación de su actividad hemolítica (HA) con glóbulos rojos de sangre humana (RBC). Interesantemente, los resultados de HA no mostraron rompimiento de los eritrocitos, sin embargo hubo un incremento de la absorbancia en función del tiempo. El extracto crudo reveló la existencia de una banda de proteína alrededor de 30 kDa por SDS-PAGE, no se encontró banda características de actinoporinas en A. pallida. Estos resultados podrían estar asociados con una concentración sub-lítica de otra familia de proteínas las cuales alteran el equilibrio osmótico y cambian el volumen de las células, sin un efecto letal a las concentraciones ensayadas.