Evaluation of Antiplasmodial activity of extracts and constituents from Ampelozizyphus amazonicus

PMID: 26664012 WOS: 000362879000003BACKGROUND: Ampelozizyphus amazonicus Ducke, a plant that is widely used by the population of the Amazonian region to prevent and treat malaria, was investigated in this work, which describes, for the first time, the antiplasmodial activity of its extracts and associates this activity with its isolated constituents. METHODS: Different extracts with solvents of increasing polarity (hexane, chloroform, ethanol, and water) were obtained of the root bark. This procedure resulted in extracts that were characterized for their constituents. The cytotoxicity and activity of the extracts against Plasmodium berghei (schizontocidal activity, liver stage) and Plasmodium falciparum (3D7 and Dd2 strains, erythrocyte stage) were assessed in vitro. RESULTS: Of the four extracts assayed against P. berghei, the chloroform extract showed the greatest activity, with an inhibitory concentration 50% (IC50) value of 30.1 µg/mL, followed by the aqueous extract (IC50 = 39.9 µg/mL). The chloroform extract exhibited the highest antiplasmodial activity in the erythrocyte stage of P. falciparum, with an IC50 value lower than 15 µg/mL. Fractionation of this more active extract led to the isolation and elucidation of pentacyclic triterpenes, lupeol, betulin and betulinic acid, which showed antiplasmodial activities with IC50 values ranging from 5.6 to 80.30 µM. The most active of these, betulinic acid, was further quantified in the extracts by high-performance liquid chromatography-photodiode array detector analyzes. The higher amount was found in the chloroform extract, which was the most active one against P. falciparum. CONCLUSION: The results obtained in this work may partly explain the popular intake of A. amazonicusas an antimalarial remedy in the Amazon region.publishersversionpublishe

Descrição da biodiversidade terrestre dos Açores

Os Açores constituem um arquipélago de nove ilhas oceânicas isoladas, onde os organismos terrestres chegaram através do vento, do mar, noutros animais e, nos tempos históricos, com a ajuda humana. Este capítulo analisa de forma detalhada aquilo que se conhece sobre a biodiversidade terrestre dos Açores. Para tal analisámos os quatro grandes grupos de organismos listados no capítulo 4: Bryophyta (musgos, antocerotas e hepáticas), Pteridophyta e Spermatophyta (fetos e fanerogâmicas), Mollusca (lesmas e caracóis) e Arthropoda (centopeias, diplópodes, crustáceos, aranhas, ácaros, insectos, etc.). O número total de espécies e/ou subespécies dos Açores pertencentes aos quatro grupos de organismos acima referidos é de cerca de 3705 (3666 espécies e 224 subespécies). No entanto, adicionando outros grupos como os vertebrados (Chordata, Vertebrata), anelídeos (Annelida), nemátodos (Nematoda) e líquenes, aquele número sobe para 4487 espécies e/ou subspecies (4443 espécies e 232 subespécies). O número total de espécies e/ou subespécies endémicas dos Açores pertencentes aos Bryophyta, Pteridophyta, Spermatophyta, Mollusca e Arthropoda totaliza as 393 (384 espécies e 44 subespécies). Os filos animais são os mais diversos em taxa endémicos (Mollusca = 49; Arthropoda = 267), com cerca de 80 % dos endemismos dos Açores. Deve ser ainda de assinalar a elevada percentagem de endemismo nos caracóis e lesmas (Mollusca) terrestres dos Açores, com cerca de 44% de endemismo. As plantas vasculares possuem 68 endemismos e os briófitos 9. Usando um estimador não paramétrico, a estimativa conservadora da riqueza de taxa endémicos terrestres de briófitos, plantas vasculares, moluscos e artrópodes rondará 530 taxa, pelo que apenas 77% dos endemismos dos Açores serão conhecidos. Em apenas alguns géneros se verificou uma taxa de especiação elevada, na sua maior parte pertencentes aos filos Mollusca e Arthropoda. A maior parte das espécies de artrópodes e moluscos endémicos são conhecidas apenas de uma ilha, enquanto que, nas plantas, uma grande fracção das espécies ocorre na maioria das ilhas. A análise das proporções das várias categorias de colonização mostra que uma grande proporção da phanerofauna de artrópodes e da flora de plantas vasculares do arquipélago é constituída por espécies introduzidas. Deste modo, as invasões por espécies exóticas constituem um problema actual e terão impactos futuros na biodiversidade dos Açores, criando um padrão de uniformização da fauna e flora. Os Açores constituem o arquipélago da Macaronésia geologicamente mais recente, estando situado mais a norte. As suas nove ilhas isoladas no meio do oceano Atlântico possuem uma grande diversidade de histórias geológicas e constituem laboratórios ecológicos e evolutivos extraordinários. Torna-se cada vez mais importante um esforço adicional nos estudos de taxonomia e ecologia de comunidades que envolvam o estudo de grupos taxonómicos mal conhecidos (fungos, líquenes, muitos grupos de artrópodes) mas também a revisão taxonómica de muitas espécies de briófitos e plantas vasculares.ABSTRACT: The Azores is a remote oceanic archipelago of nine islands where the terrestrial organisms arrived by wind, on the sea, on other animals and on historical times by human assistance. This chapter highlights what we know about Azorean terrestrial biodiversity. Four important terrestrial taxonomic groups listed in Chapter 4 are analysed in detail: Bryophyta (mosses, liverworts), Pteridophyta and Spermatophyta (ferns and phanerogamics), Mollusca (slugs and snails) and Arthropoda (millipedes, centipedes, mites, spiders, insects, etc.). Currently the total number of terrestrial species and/or subspecies of the above mentioned organisms in the Azores is estimated of about 3705 (3666 species and 224 subspecies). However, if we add other groups like vertebrates (Chordata, Vertebrata), annelids (Annelida), nematodes (Nematoda) and lichens, this number reaches 4487 species and/or subspecies (4443 species and 232 subspecies). The total number of endemic species and/or subspecies from the Azores belonging to Bryophyta, Pteridophyta, Spermatophyta, Mollusca and Arthropod is about 393 (384 species and 44 subspecies). The animals Phyla are the most diverse in endemic taxa (Mollusca = 49; Arthropoda = 267), comprising about 80% of the Azorean endemics. The percentage of endemismo within Mollusca (44%) is remarkable. Vascular plants have 68 endemic species while bryophytes have 9 endemics. Using a non-parametric estimator we obtained a conservative estimate for endemic Azorean terrestrial vascular plants, bryophytes, molluscs and arthropods around 530 taxa, which mean that only about 77% have already been described. In only some genera there was a substantial inter and intra-island speciation, most cases occurring in Mollusca and Arthropoda. Most of the endemic arthropods and molluscs are known in only one island, whereas in plants a large proportion of species occur in most islands. Na analysis of the proportions of the colonization categories in arthropods and vascular plants shows that a major proportion of the species are introduced. Therefore, invasions of alien organisms are an actual and future environmental threat in the Azores, creating a pattern of biotic homogenization that is of great contemporary concern. The Azores is the northernmost and the most recent Macaronesian archipelago. The nine islands, isolated in the middle of the Atlantic, with different geological histories, are wonderful ecological and evolutionary laboratories. An additional effort on taxonomic and community-level research implies the detailed examination of poorly studied groups (fungi, lichens, many arthropod groups), but a revision of the taxonomic status of many bryophyte and vascular plants is also deeply needed

Macroecological patterns of species distribution, composition and richness of the Azorean terrestrial biota

We investigate the macroecological patterns of the terrestrial biota of the Azorean archipelago, namely the species-range size distributions, the distance decay of similarity, and the island species–area relationship (ISAR). We use the most recent up-to-date checklists to describe the diversity at the island level for nine groups (Lichens, Fungi, Diatoms, Bryophytes, Vascular Plants, Nematodes, Molluscs, Arthropods, Vertebrates). The particularities of the Azorean biota result in some differences to the patterns commonly found in other oceanic archipelagos. Strikingly, bryophytes, molluscs and vertebrates show a bimodal species-range size distribution, and vascular plants a right unimodal distribution due the high numbers of widespread species. Such high compositional homogeneity between islands also results in non-significant or even negative decays of similarity with distance among islands for most groups. Dispersal ability, together with other particular characteristics of each taxon, also shapes these distributions, as well as the relationships between island species richness, and area and time. Strikingly, the degree of departure of the richness of the whole archipelago from the SAR of its constituent islands largely depends on the dispersal ability of each group. Comparative studies with other oceanic archipelagos of the globe are however needed to understand the biogeographical and evolutionary processes shaping the remarkably low diversity of the Azorean biota

Componentes da dieta artificial de Anthonomus grandis (Coleoptera: Curculionidae) afetam a viabilidade dos conídios de Metarhizium anisopliae (Hypocreales: Clavicipitaceae)?

Estudos tem demonstrado que Metarhizium anisopliae (Hypocreales: Clavicipitaceae) é altamente virulento a Anthonomus grandis (Coleoptera: Curculionidae) quando os adultos se alimentam de botões florais, mas quando se alimentam de dieta artificial a mortalidade dos adultos pelo fungo reduz significativamente. Desta forma, o objetivo deste trabalho foi determinar se componentes da dieta artificial de A. grandis podem afetar a germinação de M. anisopliae

Descrição da biodiversidade terrestre e marinha dos Açores

1. Os Açores são um arquipélago isolado de nove ilhas oceânicas, pertence à região biogeográfica da Macaronésia e está entre as regiões mais ricas em fungos, plantas e animais da Europa. Este capítulo destaca o que sabemos sobre os fungos, a fauna e a flora dos habitats terrestres, dulçaquícolas e marinhos dos Açores. 2. Neste capítulo, são apresentadas as estimativas do número total de espécies e subespécies conhecidas actualmente nos Açores. Todos os grupos taxonómicos terrestres mais importantes foram analisados: fungos, líquenes, diatomáceas dulçaquícolas, briófitos (musgos, hepáticas e antocerotas), plantas vasculares (licófitas, fetos, gimnospérmicas e angiospérmicas), platelmintes (vermes), nemátodos, anelídeos (minhocas), moluscos terrestres (lesmas e caracóis), artrópodes (insectos, aracnídeos, milípedes, etc.) e vertebrados (peixes de água doce, anfíbios, répteis, aves e mamíferos). A presente obra inclui também espécies do ambiente marinho, como as algas (macroalgas), a maioria dos filos de invertebrados do litoral e os vertebrados marinhos (répteis, peixes e mamíferos). As listas de espécies e subespécies (Capítulos 2-15) são baseadas nos taxa identificados numa grande variedade de publicações, tendo essa informação sido compilada por um vasto grupo de especialistas. 3. Actualmente, o número total de taxa (espécies e subespécies) terrestres nos Açores está estimado em cerca de 6164 (cerca de 6112 espécies). A inclusão de uma listagem exaustiva das espécies de aves não-nidificantes e de uma listagem preliminar de espécies de aves potencialmente nidificantes acrescenta 325 espécies e subespécies ao total das espécies açorianas. 4. O número total de espécies e subespécies endémicas terrestres dos Açores é de cerca de 452 (411 espécies). Os animais são os mais diversos em endemismos, com 331 taxa (Arthropoda = 266; Mollusca = 49; Vertebrata = 14; Nematoda = 2), compreendendo cerca de 73% dos endemismos terrestres dos Açores. A percentagem de endemismo nos Mollusca (44%) é notável. As plantas vasculares contam com 73 endemismos, os Fungi (incluindo os líquenes) têm 34 e, tanto as diatomáceas dulçaquícolas como os briófitos, incluem sete espécies endémicas. 5. Quando comparada com os arquipélagos vizinhos da Macaronésia (Madeira e Canárias), a fauna e flora terrestres dos Açores é caracterizada por uma menor taxa de endemismo, de apenas 7%, contrastando com os cerca de 20% para a Madeira e de 30% para as Canárias. 6. No que diz respeito aos organismos marinhos, são listados 1883 taxa pertencentes a 16 filos. O número total de espécies e subespécies marinhas endémicas dos Açores é de cerca de 39, a maior parte delas moluscos (29 espécies). 7. O número total de taxa terrestres e marinhos (espécies e subespécies) nos Açores, está estimado em cerca de 8047. Os organismos marinhos agora listados, perfazem cerca de 23% da biodiversidade dos Açores. 8. O número total de taxa terrestres e marinhos (espécies e subespécies) endémicos dos Açores está estimado em cerca de 491.ABSTRACT: 1. The Azores is a remote oceanic archipelago of nine islands which belongs to the Macaronesia biogeographical region and is among the richest regions concerning fungi, plant and animal diversity in Europe. This chapter highlights what we know about the Azorean terrestrial, freshwater and marine Fungi, Flora and Fauna. 2. In this chapter we summarize the current estimates of the total number of species and subspecies presently known to occur in the Azores. The most important terrestrial taxonomic groups were studied: Fungi, Lichens, Bacillariophyta (freshwater diatoms), Bryophyta sensu lato (mosses, liverworts and hornworts), vascular plants – Tracheobionta, including Lycopodiophyta (quillworts), Pteridophyta (ferns), Pinophyta (gymnosperms) and Magnoliophyta (angiosperms), Platyhelminthes (flatworms), Nematoda (roundworms), Annelida (earthworms), Terrestrial Mollusca (slugs and snails), Arthropoda (millipedes, centipedes, mites, spiders, insects, etc.) and Vertebrata (freshwater fishes, amphibians, reptiles, birds and mammals). In addition, we expand this list to the marine realm, including Algae (macroalgae), coastal invertebrates (most Phyla) and marine vertebrates (fishes, reptiles and mammals). The list of species and subspecies (Chapters 2 to 15) is based on the taxa recognized in primary published literature sources, compiled by a vast group of experts. 3. Currently the total number of terrestrial taxa (species and subspecies) in the Azores is estimated of about 6164 (about 6112 species). The inclusion of an exhaustive listing of non breeding species and a preliminary list of potentially breeding species adds 325 species and subspecies of birds to the Azorean list of species. 4. The total number of terrestrial endemic species and/or subspecies from the Azores is about 452 (411 species). Animals are the most represented in this respect, with 331 taxa (Arthropoda = 266; Mollusca = 49; Vertebrata = 14; Nematoda = 2), that is, about 73% of the Azorean terrestrial endemics. The percentage of endemism within Mollusca (44%) is remarkable. Vascular plants have 73 endemic taxa, while Fungi (including Lichens) have 34, freshwater diatoms and bryophytes have seven endemic species each. 5. Compared to the other nearest Macaronesian archipelagos (Madeira and Canaries), the Azorean terrestrial fauna and flora is characterized by a lower percentage of endemism (only 7%, which contrasts with nearly 20% for Madeira and 30% for the Canary islands). 6. Concerning the marine organisms, we listed about 1883 taxa belonging to 16 Phyla. The total number of marine endemic species and/or subspecies from the Azores is about 39, most of them being molluscs (29 species). 7. Currently, the total number of terrestrial and marine taxa (species and subspecies) in the Azores is estimated in about 8047. The marine organisms currently listed make up about 23% of the Azorean biodiversity. 8. Currently, the total number of terrestrial and marine endemic taxa (species and subspecies) in the Azores is estimated of about 491

Genetic and phenotypic variation of the malaria vector Anopheles atroparvus in southern Europe

<p>Abstract</p> <p>Background</p> <p>There is a growing concern that global climate change will affect the potential for pathogen transmission by insect species that are vectors of human diseases. One of these species is the former European malaria vector, <it>Anopheles atroparvus</it>. Levels of population differentiation of <it>An. atroparvus </it>from southern Europe were characterized as a first attempt to elucidate patterns of population structure of this former malaria vector. Results are discussed in light of a hypothetical situation of re-establishment of malaria transmission.</p> <p>Methods</p> <p>Genetic and phenotypic variation was analysed in nine mosquito samples collected from five European countries, using eight microsatellite loci and geometric morphometrics on 21 wing landmarks.</p> <p>Results</p> <p>Levels of genetic diversity were comparable to those reported for tropical malaria vectors. Low levels of genetic (0.004 <<it>F</it>_{<it>ST </it>}<0.086) and phenotypic differentiation were detected among <it>An. atroparvus </it>populations spanning over 3,000 km distance. Genetic differentiation (0.202 <<it>F</it>_{<it>ST </it>}<0.299) was higher between the sibling species <it>An. atroparvus </it>and <it>Anopheles maculipennis </it>s.s. Differentiation between sibling species was not so evident at the phenotype level.</p> <p>Conclusions</p> <p>Levels of population differentiation within <it>An. atroparvus </it>were low and not correlated with geographic distance or with putative physical barriers to gene flow (Alps and Pyrenées). While these results may suggest considerable levels of gene flow, other explanations such as the effect of historical population perturbations can also be hypothesized.</p

SARS-CoV-2 uses CD4 to infect T helper lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here, we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.</p

SARS-CoV-2 uses CD4 to infect T helper lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here, we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.</p