Potencial atividade antiviral de plexaurella regia no ciclo replicativo do vírus herpes simples tipo 1 / Potential antiviral activity of plexaurella regia on the replication of herpes simplex virus type 1

Latência e resistência de cepas de Herpes simples tipo 1 (HSV-1) ao aciclovir têm sido associados a sequelas graves em pacientes imunocomprometidos, como pacientes com AIDS. Por essa razão, a pesquisa por novas substâncias com atividade anti-HSV-1 é uma necessidade urgente. Objetivo: Investigar se os extratos obtidos de Plexaurella spp poderiam ser usados em estudos pré-clínicos de drogas contra o vírus herpes simples tipo 1. Métodos: A viabilidade celular e concentrações inibitórias das drogas foram utilizados como testes de triagem para investigar os extratos etil acetato e diclorometano de Plexaurella spp como antivirais. Resultados: Os resultados de viabilidade demonstraram que os extratos de Plexaurella regia e Plexaurella grandflora não foram citotóxicas, mas somente Plexaurella regia alcançou um valor de CC50 expressivo. Nos ensaios antivirais, Plexaurella regia mostraram um resultado ainda mais significante de concentração efetiva (EC50) e índice terapêutico (<2.5 µg/mL e 51.6 µg/mL, respectivamente) comparado com aciclovir (ACV). Conclusão: Estes resultados mostram que os extratos de corais têm atividade anti-herpética e podem contribuir para novas estratégias de redução da incidência de resistência de doenças relacionadas aos herpes vírus

Latency and resistance of acyclovir-resistant strains of Herpes simplex virus type 1 (HSV-1) have been associated with serious sequelae in immunocompromised individuals, such as AIDS patients. Consequently, the search for new substances with anti-HSV activity is both necessary and urgent. Objective: To investigate whether extracts obtained from Plexaurella spp can be used in preclinical studies of drugs against herpes simplex virus type 1. Methods: Cell viability and inhibitory drug concentrations as screening tests were used to investigate ethyl acetate and dichloromethane extracts from Plexaurella spp as antivirals. Results: The results of viability assays demonstrated that extracts from Plexaurella regia and Plexaurella grandiflora showed less cytotoxicity, but only Plexaurella regia reached a very expressive CC50 value. In antiviral assays, Plexaurella regia showed an even more significant result of effective concentration (EC50) and therapeutic index (<2.5 µg/mL and 51.6 µg/mL, respectively) compared with acyclovir (ACV). Conclusion: These results demonstrated that extracts from corals have anti-herpetic activities and could contribute towards new strategies to stop the increasing incidence of resistance in herpes-related diseases.

Diversity and pathogenic potential of vibrios isolated from Abrolhos Bank corals.

We performed the first taxonomic characterization of vibrios and other culturable microbiota from apparently healthy and diseased Brazilian-endemic corals at the Abrolhos reef bank. The diseases affecting corals were tissue necrosis in Phyllogorgia dillatata, white plague and bleaching in Mussismilia braziliensis and bleaching in Mussismilia hispida. Bacterial isolates were obtained from mucus of 22 coral specimens originated from the Abrolhos Bank (i.e. Itacolomis reef, Recife de Fora reef and Santa Barbara Island) in 2007. Vibrios counts in the water and coral mucus were approximately 104 cfu ml(-1) and 106 cfu ml(-1) respectively. One hundred and thirty-one representative vibrio isolates were identified. Most vibrio isolates (n = 79) fell into the core group using the pyrH identification marker. According to our analysis, diseased corals did not possess a unique vibrio microbiota. Vibrio species encompassed strains originated from both apparently healthy and diseased corals. The pathogenic potential of representative vibrio isolates (V. alginolyticus 40B, V. harveyi-like 1DA3 and V. coralliilyticus 2DA3) were evaluated in a standardized bioassay using the animal model Drosophila melanogaster and caused 25-88% mortality. This is the first taxonomic characterization of the culturable microbiota from the Brazilian-endemic corals. Endemic Brazilian corals are a reservoir of the vibrio core group. Vibrio alginolyticus, V. harveyi and V. coralliilyticus are dominant in the mucus of these corals and may be a normal component of the holobiont.