Antibacterial and antioxidant activities of Derriobtusone A isolated from Lonchocarpus obtusus

This study evaluated the effect of derriobtusone A, a flavonoid isolated from Lonchocarpus obtusus, on two important pathogenic bacteria, Staphylococcus aureus and Escherichia coli, as well as its antioxidant activity and toxicity. Planktonic growth assays were performed, and the inhibition of biofilm formation was evaluated. In addition, antioxidant activity was assessed by DPPH radical scavenging assay, ferrous ion chelating assay, ferric-reducing antioxidant power assay, and β-carotene bleaching assay. Toxicity was evaluated by the brine shrimp lethality test. Results showed that derriobtusone A completely inhibited the planktonic growth of S. aureus at 250 and 500 μg/mL; however, it did not have the same activity on E. coli. Derriobtusone A reduced the biomass and colony-forming unit (cfu) of S. aureus biofilm at concentrations of 250 and 500 μg/mL. In various concentrations, it reduced the biofilm biomass of E. coli, and, in all concentrations, it weakly reduced the cfu. Derriobtusone A showed highly efficient antioxidant ability in scavenging DPPH radical and inhibiting β-carotene oxidation. The compound showed no lethality to Artemia sp. nauplii. In conclusion, derriobtusone A may be an effective molecule against S. aureus and its biofilm, as well as a potential antioxidant compound with no toxicity.This study was supported by CAPES (Brazil) through the BEX NT 2052/11NT3 Project and by IBB-CEB and FCT (Portugal) and European Community Fund FEDER, through Program COMPETE, in the ambit of Project PTDC/SAU-ESA/646091/2006/FCOMP-01-0124-FEDER-007480. Otilia Deusdenia Loiola Pessoa, Benildo Sousa Cavada, and Edson Holanda Teixeira are Senior Fellows of CNPq. Mr. David Martin helped with the English editing of the paper

Ethanolic Extract of the Red Algae Meristiella echinocarpa (Areschoug) Confers Neuroprotection in Mice

Objectives: This study aimed to investigate the neuroprotective effects of the ethanolic extract obtained from red algae marine Meristiella echinocarpa (Areschougiaceae) – EEMe. Methods: EEMe was used in doses ranging from 10 to 40 mg/kg, administered intraperitoneally in mice. Behavioral tests were performed to assess locomotor activity (open field), anxiety (elevated plus maze), depression (tail suspension), and motor coordination (rota-rod). The anticonvulsant effect of the algae extract was evaluated in two models of seizures induced by strychnine and pentylenetetrazol. The level of oxidative stress was also evaluated in the following brain areas: the prefrontal cortex, hippocampus, and striatum. Statistical analysis was performed applying ANOVA followed by the Bonferroni test. Results: EEMe reduced significantly the number of crossing (36%) and rearing (54%) in the open field test and increased 1.3x the immobility time in the tail suspension test. In brain areas EEMe also reduced significantly malondialdehyde levels (striatum: 45%, hippocampus: 38%, prefrontal cortex: 37%) and nitrite levels (striatum: 72%, hippocampus: 79%, prefrontal cortex: 63%), and increased the reduced-glutathione levels (striatum: 72%, hippocampus: 73%, prefrontal cortex: 42%). In addition, the extract significantly prolonged the latency of seizures induced by strychnine (38%) or pentylenetetrazol (57%), and the latency of death induced by pentylenetetrazol (6.1x). Conclusion: EEMe exhibits antioxidant and anticonvulsant effects, probably involving GABAergic and glycinergic pathways. extract exhibits antioxidant and anticonvulsant effects, involving GABAergic and glycinergic pathways.

Vibrio em amostras de água de viveiros de cultivo do camarão marinho Litopenaeus vannamei, no Ceará-Brasil

The present study analyzed 24 samples of water from ponds of a shrimp farm in Ceará (Brazil) rearing Litopenaeus vannamei. Vibrio diversity was determined from the Most Probable Number (MPN) of vibrios, the number of isolated and phenotyped Vibrio strains. MPN values ranged from 43 x 104 to 11 x 1013 MPN/100mL. The 55 Vibrio strains isolated belonged to 7 species: V. cholerae (21,8%), V. harveyi (20%), V. parahaemolyticus (16,4%) e V. anguillarum (12,8%).Foram analisadas 24 amostras de água de viveiros de cultivo do camarão marinho Litopenaeus vannamei no Estado do Ceará, Brasil. A pesquisa de diversidade de espécies de Vibrio foi realizada a partir da determinação do Número Mais Provável (NMP), isolamento e identificação fenotípica dos víbrios isolados. Os índices de NMP/100mL variaram de 43 x 104 a 11 x 1013. Dos 55 isolados de Vibrio, foram identificadas 7 espécies, com predominância de V. cholerae não O1/não O139 (21,8%), V. harveyi (20%), V. parahaemolyticus (16,4%) e V. anguillarum (12,8%)

Vibrio in ponds of a shrimp farm rearing litopenaeus vannamei, in Ceará-Brazil

Foram analisadas 24 amostras de água de viveiros de cultivo do camarão marinho Litopenaeus vannamei no Estado do Ceará, Brasil. A pesquisa de diversidade de espécies de Vibrio foi realizada a partir da determinação do Número Mais Provável (NMP), isolamento e identificação fenotípica dos víbrios isolados. Os índices de NMP/100mL variaram de 43 x 104 a 11 x 1013. Dos 55 isolados de Vibrio, foram identificadas 7 espécies, com predominância de V. cholerae não O1/não O139 (21,8%), V. harveyi (20%), V. parahaemolyticus (16,4%) e V. anguillarum (12,8%).The present study analyzed 24 samples of water from ponds of a shrimp farm in Ceará (Brazil) rearing Litopenaeus vannamei. Vibrio diversity was determined from the Most Probable Number (MPN) of ibrios, the number of isolated and phenotyped Vibrio strains. MPN values ranged from 43 x 104 to 11 x 1013 MPN/100mL. The 55 Vibrio strains isolated belonged to 7 species: V. cholerae (21,8%), V. harveyi (20%), V. parahaemolyticus (16,4%) e V. anguillarum (12,8%)

Susceptibilidade "in vitro" a antimicrobianos de estirpes de Vibrio spp isoladas de camarões (Litopenaeus vannamei) e de água de criação destes animais provenientes de uma fazenda de camarões no Ceará Nota prévia

Foram feitos ensaios de susceptibilidade a antibióticos em 48 cepas de Vibrio isoladas do cultivo do Litopenaeus vannamei no Ceará. Para os testes de difusão foram utilizados 11 antibióticos. A espécie que apresentou maior percentagem de resistência aos antimicrobianos foi V. cholerae, onde 33,33% das 12 cepas testadas mostraram-se resistentes a sulfazotrim, 25% a ampicilina e 33,33% a ceftriaxona.Suscetibility assays were performed for 48 Vibrio strains isolated from pond-reared Litopenaeus vannamei in Ceará, Brazil. The diffusion assays tested 11 antibiotics. The most resistant species was V. cholerae: of 12 strains tested, one third was resistant to sulfamethoxazole-trimethoprim, one fourth to ampicillin and one third to ceftriaxone

Antioxidant, hemolytic, antimicrobial, and cytotoxic activities of the tropical Atlantic marine zoanthid Palythoa caribaeorum

Marine invertebrates are capable of synthesizing bioactive compounds, which may be beneficial to human health. The aim of this study was to evaluate the antioxidant, hemolytic, antimicrobial and cytotoxic activities of crude extract (70% EtOH), and dichloromethane (DCM), ethyl acetate (EtOAc), and aqueous (Aq) fractions of the marine zoanthid Palythoa caribaeorum. The phenolic compound contents of the crude extract, DCM, EtOAc and Aq fractions were 12.33, 18.17, 10.53, and 3.18 mg GAE per gram, respectively. DPPH radical scavenging activity showed slight variation. IC50 of crude extract, DCM, EtOAc and Aq fractions were 11.13, 11.25, 11.74, and 11.28 µg mL-1, respectively. Among the sample, ferrous ion chelating was the highest in crude extract (IC50 302.90 µg mL-1), followed by EtOAc, Aq, and DCM fractions with 457.77, 547.91, and 641.82 µg mL-1, respectively. Ferric-reducing antioxidant power showed optical density at about 0.5. The samples tested exhibited low hemolytic activity under 10% up to a concentration of 50 μg mL-1. No antimicrobial activity was observed against any of the tested bacterial strains. For the cytotoxic activity, LC50 of DCM, crude extract, EtOAc, and Aq were 52.10, 83.06, 86.34, and 117.45 μg mL-1, showing high toxicity.</jats:p