Loading...
8 results
Search Results
Now showing 1 - 8 of 8
- Antileishmanial activity of meroditerpenoids from the macroalgae Cystoseira baccataPublication . Sousa, Carolina Bruno de; Gangadhar, Katkam N.; Morais, Thiago R.; Conserva, Geanne A. A.; Vizetto-Duarte, C; Pereira, H.; Laurenti, Marcia D.; Campino, Lenea; Levy, Debora; Uemi, Miriam; Barreira, Luísa; Custódio, L.; Passero, Luiz Felipe D.; Lago, Joao Henrique G.; Varela, JoãoThe development of novel drugs for the treatment of leishmaniases continues to be crucial to overcome the severe impacts of these diseases on human and animal health. Several bioactivities have been described in extracts from macroalgae belonging to the Cystoseira genus. However, none of the studies has reported the chemical compounds responsible for the antileishmanial activity observed upon incubation of the parasite with the aforementioned extracts. Thus, this work aimed to isolate and characterize the molecules present in a hexane extract of Cystoseira baccata that was found to be bioactive against Leishmania infantum in a previous screening effort. A bioactivity-guided fractionation of the C. baccata extract was carried out and the inhibitory potential of the isolated compounds was evaluated via the MIT assay against promastigotes and murine macrophages as well as direct counting against intracellular amastigotes. Moreover, the promastigote ultrastructure, DNA fragmentation and changes in the mitochondrial potential were assessed to unravel their mechanism of action. In this process, two antileishmanial meroditerpenoids, (3R)- and (3S)-tetraprenyltoluquinol (1a/1b) and (3R)- and (3S)-tetraprenyltoluquinone (2a/2b), were isolated. Compounds 1 and 2 inhibited the growth of the L. infantum promastigotes (IC50 = 44.9 +/- 4.3 and 94.4 +/- 10.1 mu M, respectively), inducing cytoplasmic vacuolization and the presence of coiled multilamellar structures in mitochondria as well as an intense disruption of the mitochondrial membrane potential. Compound 1 decreased the intracellular infection index (IC50 = 25.0 +/- 4.1 mu M), while compound 2 eliminated 50% of the intracellular amastigotes at a concentration > 88.0 mu M. This work identified compound 2 as a novel metabolite and compound 1 as a biochemical isolated from Cystoseira algae displaying antileishmanial activity. Compound 1 can thus be an interesting scaffold for the development of novel chemotherapeutic molecules for canine and human visceral leishmaniases studies. This work reinforces the evidence of the marine environment as source of novel molecules. (C) 2017 Elsevier Inc. All rights reserved.
- A diverse assemblage of RNA and DNA viruses found in mosquitoes collected in southern PortugalPublication . Silva, Manuel; Morais, Paulo; Maia, Carla; Sousa, Carolina Bruno de; Gouveia de Almeida, Antonio Paulo; Parreira, RicardoThis work describes the detection and partial characterization of mosquito-borne virus genomic sequences, based on the analysis of mosquitoes collected from the Spring to Fall of 2018 in the Algarve (southern Portugal). The viral survey that was carried out using multiple primer sets disclosed the presence of both RNA and DNA viral sequences in these mosquitoes, which were subsequently analysed using maximum likelihood and Bayesian phylogenetic reconstruction methods. The obtained results brought to light three lineages of insect-specific flaviviruses, a monophyletic cluster of bunyaviruses from an unassigned group within the Phenuiviridae family, as well as brevidensoviruses (Parvoviridae, Densovirinae:). The latter two groups of viruses were here described for the first time in mosquitoes from Portugal. Results relating to the tentative isolation of the putative viruses identified in C6/36 cells are also shown, and the serendipitous, although not unexpected, isolation a Negev-like Nelorpivirus from Culex laticinctcus mosquitoes is reported.
- Cystoseira algae (Fucaceae): update on their chemical entities and biological activitiesPublication . Bruno De Sousa, Carolina; Gangadhar N. Katkam, Dr.; Macridachis, Jorge; Pavao, Madalena; Morais, Thiago R.; Campino, Lenea; J. C. or Varela J. or Varela J.C.S., Varela; Lago, Joao Henrique G.Cystoseira (Sargassaceae) is a genus of marine brown algae composed of about 40 species, which is distributed along the Eastern Atlantic and Mediterranean coasts. The biological potential of the Cystoseira genus has been investigated and several activities have been reported. Chemically, this genus contains a wide variety of secondary metabolites, such as terpenoids, steroids, phlorotannins and phenolic compounds. Additionally, other chemical components as, for instance, carbohydrates, triacylglycerolsgatty acids, pigments as well as vitamins have been identified in the studied species. Some of the isolated compounds were associated with the reported pharmacological properties, as for example antioxidant, anti-inflammatory, cytotoxicity, anticancer, cholinesterase inhibition, anti-diabetic, activities but also antibacterial, antifungal and anti-parasitic activities. In this review, we provide a comprehensive overview of the compounds isolated and identified after 1995 from the different species of Cystoseira, compiling more than 200 compounds isolated, together with their therapeutic potential. (C) 2017 Elsevier Ltd. All rights reserved.
- Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red SeaPublication . Pereira, Hugo; Custodio, Luisa; Rodrigues, Maria Joao; Bruno De Sousa, Carolina; Oliveira, Marta; Barreira, Luísa; Neng, Nuno da Rosa; Florencio Nogueira, Jose Manuel; Alrokayan, Salman A.; Mouffouk, Fouzi; Abu-Salah, Khalid M.; Ben-Hamadou, Radhouan; Varela, JoãoFour lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.
- Report of in vitro antileishmanial properties of Iberian macroalgaePublication . Bruno De Sousa, Carolina; Lago, Joao Henrique G.; Macridachis, Jorge; Oliveira, Marta; Fonseca Brito, Luis; Vizetto-Duarte, Catarina; Florindo, Claudia; Hendrickx, Sarah; Maes, Louis; Morais, Thiago; Uemi, Miriam; Neto, Luis; Dionísio, Lídia; Cortes, Sofia; Barreira, Luísa; Custódio, Luísa; Albericio, Fernando; Campino, Lenea; Varela, J.Here is reported the anti Leishmania infantum activity of 48 hexane, CH2Cl2 and MeOH extracts from 16 macroalgae collected on the Iberian Coast. Seven hexane and CH2Cl2 Cystoseira baccata, Cystoseira barbata, Cystoseira tamariscifolia, Cystoseira usneoides, Dictyota spiralis and Plocamium cartilagineum extracts were active towards promastigotes (IC50 29.8-101.8 mu g/mL) inducing strong morphological alterations in the parasites. Hexane extracts of C. baccata and C. barbata were also active against intracellular amastigotes (IC50 5.1 and 6.8 mu g/mL, respectively). Fatty acids, triacylglycerols, carotenoids, steroids and meroterpenoids were detected by nuclear magnetic resonance (NMR), and gas chromatography in the Cystoseira extracts. These results suggest that Cystoseira macroalgae contain compounds with antileishmanial activity, which could be explored as scaffolds to the development of novel sources of antiparasitic derivatives. [GRAPHICS] .
- The Southwestern fringe of Europe as an important reservoir of caprine biodiversityPublication . Martinez, Amparo M.; Gama, Luis T.; Delgado, Juan V.; Canon, Javier; Amills, Marcel; Bruno de Sousa, Carolina; Ginja, Catarina; Zaragoza, Pilar; Manunza, Arianna; Landi, Vincenzo; Sevane, NataliaBackground: Portugal and Spain, with six and 22 officially recognized caprine breeds, encompass 25 % of the European Union goat census. Many of these populations have suffered strong demographic declines because of competition with exotic breeds and the phasing-out of low income rural activities. In this study, we have investigated the consequences of these and other demographic processes on the genetic diversity, population structure and inbreeding levels of Iberian and Atlantic goats. Methods: A sample of 975 individuals representing 25 officially recognized breeds from Portugal and Spain, two small populations not officially recognized (Formentera and Ajui goats) and two ecotypes of the Tinerfena and Blanca Celtiberica breeds were genotyped with a panel of 20 microsatellite markers. A wide array of population genetics methods was applied to make inferences about the genetic relationships and demography of these caprine populations. Results: Genetic differentiation among Portuguese and Spanish breeds was weak but significant (F-ST = 0.07; P < 0.001), which is probably the consequence of their short splitting times and extensive gene flow due to transhumance. In contrast, Canarian goats were strongly differentiated because of prolonged geographic isolation. Most populations displayed considerable levels of diversity (mean H-e = 0.65). Conclusions: High diversity levels and weak population structures are distinctive features of Portuguese and Spanish breeds. In general, these local breeds have a reduced census, but are still important reservoirs of genetic diversity. These findings reinforce the need for the implementation of management and breeding programs based on genetic data in order to minimize inbreeding, maintain overall genetic and allelic diversities and breed identities, while at the same time taking into account the within-breed genetic structure.
- Report of in vitro antileishmanial properties of Iberian macroalgaePublication . Bruno De Sousa, Carolina; Lago, João Henrique G.; Macridachis, Jorge; Oliveira, Marta; Brito, Luis; Vizetto-Duarte, C; Florindo, Claudia; Hendrickx, Sarah; Maes, Louis; Morais, Thiago; Uemi, Miriam; Neto, Luís; Dionísio, Lídia; Cortes, Sofia; Barreira, Luísa; Custódio, Luísa; Alberício, Fernando; Campino, Lenea; Varela, JoãoHere is reported the anti Leishmania infantum activity of 48 hexane, CH2Cl2 and MeOH extracts from 16 macroalgae collected on the Iberian Coast. Seven hexane and CH2Cl2Cystoseira baccata, Cystoseira barbata, Cystoseira tamariscifolia, Cystoseira usneoides, Dictyota spiralis and Plocamium cartilagineum extracts were active towards promastigotes (IC50 29.8-101.8 μg/mL) inducing strong morphological alterations in the parasites. Hexane extracts of C. baccata and C. barbata were also active against intracellular amastigotes (IC50 5.1 and 6.8 μg/mL, respectively). Fatty acids, triacylglycerols, carotenoids, steroids and meroterpenoids were detected by nuclear magnetic resonance (NMR), and gas chromatography in the Cystoseira extracts. These results suggest that Cystoseira macroalgae contain compounds with antileishmanial activity, which could be explored as scaffolds to the development of novel sources of antiparasitic derivatives.
- Improved phylogeny of brown algae Cystoseira (Fucales) from the Atlantic-Mediterranean region based on mitochondrial sequencesPublication . Bruno De Sousa, Carolina; Cox, Cymon; Brito, Luís; Pavão, Maria Madalena; Pereira, Hugo; Ferreira, Ana; Ginja, Catarina; Campino, Lenea; Bermejo, Ricardo; Parente, Manuela; J. C. or Varela J. or Varela J.C.S., VarelaCystoseira is a common brown algal genus widely distributed throughout the Atlantic and Mediterranean regions whose taxonomical assignment of specimens is often hampered by intra- and interspecific morphological variability. In this study, three mitochondrial regions, namely cytochrome oxidase subunit 1 (COI), 23S rDNA (23S), and 23S-tRNAVal intergenic spacer (mt-spacer) were used to analyse the phylogenetic relationships of 22 Cystoseira taxa (n = 93 samples). A total of 135 sequences (48 from COI, 43 from 23S and 44 from mt-spacer) were newly generated and analysed together with Cystoseira sequences (9 COI, 31 23S and 35 mt-spacer) from other authors. Phylogenetic analysis of these three markers identified 3 well-resolved clades and also corroborated the polyphyletic nature of the genus. The resolution of Cystoseira taxa within the three clades improves significantly when the inclusion of specimens of related genera was minimized. COI and mt-spacer markers resolved the phylogeny of some of the Cystoseira taxa, such as the C. baccata, C. foeniculacea and C. usneoides. Furthermore, trends between phylogeny, embryonic development and available chemotaxonomic classifications were identified, showing that phylogenetic, chemical and morphological data should be taken into account to study the evolutionary relationships among the algae currently classified as Cystoseira. The resolution of Cystoseira macroalgae into three well supported clades achieved here is relevant for a more accurate isolation and identification of natural compounds and the implementation of conservation measures for target species.