Brazilian Plant Species Research Articles

Temporal changes in population genetics of six threatened Brazilian plant species in a fragmented landscape

Anthropic pressure has caused several changes in the environment, such as habitat loss and fragmentation. One effective way to evaluate its effects on population genetics is to monitor populations through time. We aimed to characterize the population genetics of six plant species at two different times (cohorts). We asked (1) if populations show genetic divergence between cohorts, (2) if any significant changes are present between the genetic index of cohorts and, if so, (3) whether such changes are related to the adult cohort fixation index. To address these questions, we studied 61 populations of 50 adult and 50 seedling individuals genotyped with allozyme markers. We calculated allelic richness (Ar), observed (Ho) and expected heterozygosity (He), and fixation index (f) for each population cohort; and pairwise FST between cohorts. Seedlings were genetically similar to the adults (mean pairwise FST = 0.014). No difference was found in the proportion of populations that showed increases and decreases of the genetic indexes over cohorts, except f, for which more populations showed a decrease. Adult fixation index had a correlation with Ho (r = 0.507, p = 3∙10−5) and He (r = −0.247, p = 0.055). A mean test between cohorts revealed the maintenance of high f values in Araucaria angustifolia and Ocotea catharinensis, as well as a significant decrease in He of Euterpe edulis, species widely explored in the past. Although we only studied two cohorts, general trends and significant changes were detected, which could be important in the conservation of those six species.

Chemical analysis of the semipurified extract of Paullinia cupana and evaluation of in vitro inhibitory effects against Helicobacter pylori

Paullinia cupana Kunth, commonly known as guarana, is a native Brazilian plant species from the Amazon area that presents various biological effects, including antimicrobial action. The aim of this study was to chemically analyse the semipurified aqueous extract (AqF) of the plant and to evaluate the activity of crude (CE), ethyl-acetate (EAF), and AqF extracts against Helicobacter pylori. The chemical profile of AqF was determined based on solid analysis 13C-NMR, direct infusion mass spectrometry (ESI-MS), and MALDI-TOF. The 13C-NMR spectrum showed characteristics of flavan-3-ol and oligomeric proanthocyanidins. ESI-MS revealed the presence of procyanidin, caffeic acid and its derivatives. MALDI-TOF analysis detected procyanidins of up to 6 units and profisetinidins of up to 5 units. Whereas CE and EAF showed inhibitory activity against H. pylori, CE, EAF, and AqF presented not high inhibitory activity against urease. The results demonstrate the potential of P. cupana to control and prevent H. pylori infection.

Natural Products: Perspectives and Challenges for use of Brazilian Plant Species in the Bioeconomy.

The development of our society has been based on the use of biodiversity, especially for nutrition, medicines and beauty. Brazil is the nation with the largest biodiversity in the world, with a rich chemical diversity, which is a potential source for bioeconomy. Considering the chemical and biological diversity of the Brazilian territory, we would like to highlight the value of secondary metabolites from Brazilian biodiversity with potential application for new products and technologies and the importance of scientific programs to support the sustainable use of biodiversity.

In vitro antileishmanial activity of leaf and stem extracts of seven Brazilian plant species

Ethnopharmacological relevanceLeishmaniasis is a parasitic disease that affects people all over the world. The number of cases of leishmaniasis is increasing and the drugs used for its treatment are toxic and not always effective. The recognition of the global nature of this disease and its direct or indirect effects on health economics and actions focuses attention on the development of new therapeutic options. In Brazil, this parasitic disease is endemic in many regions. The plants used by the population against leishmaniasis can be good starting points in the search of new lead compounds for antileishmanial drugs. Aim of the studyThe aim of the present study was to investigate the antileishmanial activity of extracts from leaves and stems of seven Brazilian plant species used by the population to treat leishmaniasis, and symptoms that might be related to Leishmania infections. Materials and methodsTwenty two extracts from seven plants belonging to five different botanical families were prepared by different methods and evaluated for their effect on the viability of promastigote forms of Leishmania infantum (MHOM/BR/1967/BH46) using the resazurin-based colorimetric assay. The extracts were considered active when they inhibited the growth of promastigotes in a percentage greater than or equal to 50% at 100 and 200 µg/mL. The active samples were further investigated to determine IC50, CC50 and SI values against promastigote forms of L. infantum. The active and non-cytotoxic extracts (SI> 10) were evaluated against amastigote forms of L. infantum. In addition, the active extracts against the amastigote forms were analyzed by TLC and HPLC, while the EtOAc extract of stems from Aspidosperma tomentosum was also evaluated by GC/MS. ResultsAmong the twenty two extracts evaluated, two were considered active against L. infantum. The EtOH extract of leaves from Dyospiros hispida (IC50 55.48 ± 2.77 µg/mL and IC50 80.63 ± 13.17 µg/mL, respectively) and the EtOAc extract of stems from Aspidosperma tomentosum (IC50 9.70 ± 2.82 µg/mL and IC50 15.88 ± 1.53 µg/mL, respectively) inhibited significantly the growth of promastigote and amastigote forms of L. infantum. Some extracts, although active in the initial screening, were considered toxic since the SI was lower than 10. In TLC and HPLC analysis the leaf extract of Dyospiros hispida showed the presence of anthraquinones, terpenes and saponins, and in the EtOAc extract of stems from Aspidosperma tomentosum alkaloids and flavonoids were detected. In addition, in the latter extract the indole alkaloids uleine and dasycarpidone could be identified by GC/MS. ConclusionsThe ethnopharmacological data of Aspidosperma tomentosum and Dyospiros hispida in part support the results found in the biological models used. Extracts of Aspidosperma tomentosum and Dyospiros hispida presented promising results against L. infantum.

Poiretia latifolia essential oil as a promising antifungal and anti-inflammatory agent: Chemical composition, biological screening, and development of a nanoemulsion formulation

Poiretia latifolia is a Brazilian plant species used in traditional medicine for a wide range of ailments. The objective of this study was to evaluate the antioxidant potential, anti-inflammatory activity, and antifungal effect of P. latifolia essential oil and its major compounds. In addition, a nanoemulsified system was developed for its application. Aerial parts of the plant, collected at different stages of development, were hydrodistilled, and the chemical composition of the oil was determined by gas chromatography–mass spectrometry (GC–MS). Limonene, trans-dihydrocarvone, and carvone were identified as major compounds. Antioxidant potential was evaluated by three different methods: TBARS, β-carotene/linoleic acid, and DPPH. P. latifolia oil showed antioxidant activity (0.508 mg/mL) in lipophilic medium, as evidenced by the β-carotene/linoleic acid assay. The anti-chemotactic effect of the oil was evaluated by inhibition of neutrophil migration (0.001–10 μg/mL): P. latifolia oil was able to inhibit up to 94.7% of migration. Antifungal activity was evaluated against yeasts (Candida spp.) and dermatophytic filamentous fungi (Microsporum spp. and Trichophyton spp.). P. latifolia oil showed antifungal activity against Microsporum canis, and a mixture of carvone and limonene was effective against the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes. Nanoemulsions were successfully developed. P. latifolia oil has the potential to be used as an antidermatophytic and anti-inflammatory agent.

Temperature effects on Zn-responses and Zn-reclamation capacity of two native Brazilian plant species: Implications of climate change

Climate changes implications on the physiological responses and Zn-reclamation capacity of two native Brazilian plant species [Albizia polycephala and Pterogyne nitens (Fabaceae)] were studied. Plants were grown in substrate amended with 0 and 200 mg kg−1, under increasing temperatures (25 °C, 30 °C and 35 °C) and plant physiological responses related to energetic and oxidative metabolism and Zn-uptake and subcellular localization were evaluated. By impairing the mitochondrial metabolism, Zn was seen to induce hydrogen peroxide (H2O2) production, which was stimulated by increasing temperature. However, increasing temperature was also seen to stimulate the activity of antioxidant enzymes, attenuating oxidative damage induced by H2O2 in leaves and roots. Moreover, increasing temperature was responsible for changes in the subcellular localization of Zn, increasing its allocation in the soluble fraction (mainly composed of vacuoles and cytoplasm) - which could be a tolerance mechanism allowing plants to survive in conditions of toxic levels of Zn under increased temperatures. Our results point to an interactive effect of rising temperature on Zn toxicity to plants. Although rising temperatures led to increased uptake of Zn and increased its deleterious effects to mitochondria metabolism (which led to increased H2O2 production), the increases in temperature also promoted the activity of antioxidant enzymes, responsible for H2O2 scavenging, thus attenuating the deleterious effects of this ROS on the cell metabolism of plants. Finally, increases in temperature do not constrain the ability of A. polycephala and P. nites to reclaim Zn and, therefore, these species should continue to be used in Zn-phytoremediation programs even given the prospects of increasing temperatures over the next century due to climatic changes.

A Cyclotide Isolated from Noisettia orchidiflora (Violaceae).

Biologically active cyclotides have been found on some flowering plants species and are involved in the role of the plant protection. As part of studies focusing on peptides from Brazilian plant species, we are reporting the detection by LC-MS of several cyclotides from leaves and stems of Noisettia orchidiflora (Violaceae). From stems it was possible to isolate and characterize a cyclotide named Nor A. Its primary structure (amino acid sequence) was established by MALDI-TOF-MS, based on the y- and b-type ion series, after reduction and alkylation reactions, as well as enzymatic digestion using the enzymes endoproteinase glutamic acid (endoGlu-C), trypsin, and chymotrypsin. Furthermore, the amino acid analysis was also described.

Plant-Knowledge Adaptation in an Urban Setting: Candomblé Ethnobotany in New York City

Candomble is an African-Brazilian religion that resulted from the adaptation of West African (especially Yoruba) beliefs in Brazil during and after the slave trade. This study seeks to understand the current evolution of Candomble ethnobotanical knowledge as it travels from Brazil to New York City (NYC), therefore going through a second adaptation process. We identified which Brazilian plant species are still in use, which are being incorporated and/or replaced, and what factors are contributing to the ethnobotanical adaptation that is taking place in NYC. To accomplish this, we compiled an inventory of liturgical plants used by five highly skilled Candomble practitioners living in NYC and then compared the vernacular and binomial Latin names of these plants to inventories previously published in Brazil by other authors. By doing this, we were able to distinguish patterns of knowledge continuity, assimilation, or substitution. Nearly two-thirds of the species identified in NYC’s inventory were cases of knowledge continuity, where most plants were used by at least four practitioners. Many of these frequently used species have survived the adaptation process from Africa to Brazil, and now from Brazil to NYC. Practitioners also assimilated (20%) and substituted (16%) some species. The assimilation process was mainly influenced by Santeria, another Yoruba-derived religion widely practiced in NYC. Substitutions, however, were driven by two distinct forces. In one cohort (7%), species were morphologically and organoleptically similar to the original material, and replacements were mostly influenced by the easy accessibility of botanical materials. The other cohort (9%) was marked by a logical substitution process based on Yoruba rules of plant classification. Our results show that Candomble practitioners in NYC are maintaining a notable level of cultural continuity, while cautiously assimilating new species and consciously or subconsciously replacing others. Although both accessibility of plant material and cultural forces play a role in the adaptation mechanism, the latter appears to be the most relevant to these highly skilled practitioners.

Reproductive biology and pollination of the carnivorous Genlisea violacea (Lentibulariaceae).

Genlisea violacea is a Brazilian endemic carnivorous plant species distributed in the cerrado biome, mainly in humid environments, on sandy and oligotrophic soil or wet rocks. Studies on reproductive biology or pollination in the Lentibulariaceae are notably scarce; regarding the genus Genlisea, the current study is the first to show systematic and standardised research on reproductive biology from field studies to describe the foraging of visiting insects and determine the effective pollinators of Genlisea. We studied two populations of G.violacea through the observation of flower visitors for 4months of the rainy and dry seasons. Stigmatic receptivity, pollen viability, and breeding system were evaluated together with histochemistry and morphological analyses of flowers. The flowers showed stigmatic receptivity of 100% in open buds and mature flowers, reducing to 80% for senescent flowers. Nearly 80% of pollen grains are viable, decreasing to 40-45% after 48h. Nectar is produced by glandular trichomes inside the spur. Two bee species are effective pollinators: one of the genus Lasioglossum (subgenus Dialictus: Halictidae) and the other of the genus Ceratina (subgenus Ceratinula: family Apidae). Moreover, bee-like flies of the Syrphidae family may also be additional pollinators. Genlisea violacea is an allogamous and self-compatible species. The differences in flower-visiting fauna for both populations can be attributed to factors such as climate, anthropogenic effect, seasonal factors related to insects and plants, as well as the morphological variation of flowers in both populations.

Antimycobacterial and antimalarial activities of endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from Brazil.

BACKGROUND Endophytic fungi, present mainly in the Ascomycota and Basidiomycota phyla, are associated with different plants and represent important producers of bioactive natural products. Brazil has a rich biodiversity of plant species, including those reported as being endemic. Among the endemic Brazilian plant species, Vellozia gigantea (Velloziaceae) is threatened by extinction and is a promising target to recover endophytic fungi.OBJECTIVE The present study focused on bioprospecting of bioactive compounds of the endophytic fungi associated with V. gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil.METHODS The capability of 285 fungal isolates to produce antimicrobial and antimalarial activities was examined. Fungi were grown at solid-state fermentation to recover their crude extracts in dichloromethane. Bioactive extracts were analysed by chromatographic fractionation and NMR and displayed compounds with antimicrobial, antimycobacterial, and antimalarial activities.FINDINGS Five fungi produced antimicrobial and antimalarial compounds. Extracts of Diaporthe miriciae showed antifungal, antibacterial, and antimalarial activities; Trichoderma effusum displayed selective antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare; and three Penicillium species showed antibacterial activity. D. miriciae extract contained highly functionalised secondary metabolites, yielding the compound epoxycytochalasin H with high antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum, with an IC50 approximately 3.5-fold lower than that with chloroquine.MAIN CONCLUSION Our results indicate that V. gigantea may represent a microhabitat repository hotspot of potential fungi producers of bioactive compounds and suggest that endophytic fungal communities might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.

Nutraceutical potential of Byrsonima cydoniifolia fruits based on chemical composition, anti-inflammatory, and antihyperalgesic activities

In recent years, the fruits of native Brazilian plant species with anti-inflammatory property have gained prominence due to their properties comparable to traditional medicines. This study aimed to chemically characterize and evaluate the anti-inflammatory and antihyperalgesic activity of Byrsonima cydoniifolia fruit, which is widely used to manufacture ice cream and jellies. Our results revealed that the fruit exhibits flavonoid derivatives and stilbenes, as trans-piceatannol and resveratrol, as main secondary metabolites. In mice, the hydroethanolic extract of fruit reduced the edema, migration of polymorphonuclear leukocytes into the peritoneal cavity, as well as abdominal writhings. The results demonstrated, for the first time, the presence of stilbenoids in the Byrsonima genus and the anti-inflammatory and antihyperalgesic effect of Byrsonima cydoniifolia fruits, supporting its potential as a nutraceutical food.

Terpenoids from Leaves of Guarea macrophylla Display In Vitro Cytotoxic Activity and Induce Apoptosis In Melanoma Cells.

Guarea macrophylla is a Brazilian plant species that has been used in folk medicine to treat a range of diseases. Our ongoing work focuses on the discovery of new bioactive natural products derived from Brazilian flora. The current study describes the identification of cytotoxic compounds from the EtOH extract of leaves from G. macrophylla using bioactivity-guided fractionation. This approach resulted in the isolation and characterization of four compounds: cycloart-23E-ene-3β,25-diol (1), (23S*,24S*)-dihydroxycicloart-25-en-3-one (2), isopimara-7,15-diene-2α,3β-diol (3), and isopimara-7,15-dien-3β-ol (4), in which 2 and 3 are identified as new derivatives. In vitro assays were conducted to evaluate the cytotoxic activity of compounds 1-4 against a panel of cancer cell lines and to determine the possible mechanism(s) related to the activity of the compounds on B16F10Nex2 cells. The most active compound 1 induced cytotoxic effects on tumor cells, with IC50 values of 18.3, 52.1, and 58.9 µM against HL-60, HeLa, and B16F10-Nex2 tumor cells, respectively. Furthermore, it was observed in melanoma cells that compound 1 induced several specific apoptotic hallmarks, such as morphological changes in the cell shape structure, nuclear DNA condensation, specific chromatin fragmentation, and disruption in the mitochondrial membrane potential, which are related to the intrinsic apoptotic pathway.

Trade-offs among ecosystem services under different pinion harvesting intensities in Brazilian Araucaria Forests

ABSTRACTAssessing the consequences of human exploitation at different intensities on ecosystem services is important in the Brazilian Araucaria Forest biome, because it has been drastically reduced, mainly due to the exploitation of Araucaria angustifolia (Bertol.) Kuntze for wood. The inclusion of A. angustifolia on the list of Brazilian endangered plant species places the harvesting of Araucaria nuts as the most important provisioning service in this type of ecosystem. The aim of this study was to determine the trade-offs related to provisioning, supporting and regulating ecosystem services in the Araucaria Forest at different intensities of nut harvesting, by addressing ecosystem attributes that assure forest sustainability. Six indicators of ecosystem services were evaluated in harvested and non-harvested areas in Brazilian Araucaria Forest fragments. Trade-offs were examined under five harvesting intensities. The supporting services were the most sensitive to the harvesting intensity. The results indicate that a harvesting threshold of between 60% and 85% of the nuts produced guarantees forest sustainability. In addition, areas under higher harvesting intensities provide more short-term benefit services at the local scale that can be included in the formal market.EDITED BY John Parrotta

Mites (Arachnida, Acari) on Astronium fraxinifolium Schott (Anacardiaceae) from the Cerrado remnants associated with nickel mining areas

The Cerrado biome suffers constant impacts mainly due to agricultural activities, which can reduce food resources and habitats for many plant-dwelling mites, including important species to agriculture, such as predators. However, the mite fauna from this biome are still poorly known. Here, we present a checklist of mite species on Astronium fraxinifolium Schott, a Brazilian plant species threatened with extinction, from the Cerrado remnants associated with nickel mining areas, in the Niquelândia municipality, Brazil. Moreover, we performed cumulative (Mao Tau) and estimated (Jackknife 1) species accumulation curves in order to test for an effect of sampling effort and to estimate the potential number of species sheltered by the studied Cerrado remnants, and NMDS and ANOSIM analyses to test for similarity in mite species composition among samples. We sampled five A. fraxinifolium plants in each of six Cerrado remnants. Among these, three remnants were preserved (PR) and three were experiencing a secondary regeneration process (SR). Both PR and SR remnants were close to nickel mining areas. We recorded 1,562 mites including 17 species from 12 genera and eight families. Tetranychidae was the most diverse family, followed by Phytoseiidae and Tenuipalpidae. The most abundant species were phytophagous mites, namely Brevipalpus sp.1, Oligonychus sp., Eotetranychus sp.1, and the predator Agistemus brasiliensis Matioli, Ueckermann & Oliveira. Regarding feeding behavior, phytophagous mites were the most abundant and diverse on A. fraxinifolium. Both species accumulation curves (Mao Tau) for PR and SR remnants trended towards an asymptote, while estimated curves (Jackknife 1) proved to be similar to accumulation curves (Mao Tau). These results indicate that sampling was sufficient to assess mite assemblages using the methods applied in this study. No differences in mite species composition were observed between PR and SR areas. This paper is a pioneer report of mite assemblages on A. fraxinifolium. Furthermore, we report here two genera and one species recorded for the first time in the Cerrado biome. Our checklist can contribute to bridging the knowledge gap on the occurrence of plant mite species in Brazilian natural vegetation remnants.

Flowering phenology of Mouriri guianensis (Melastomataceae) and its interaction with the crepuscular bee Megalopta amoena (Halictidae) in the restinga of Lençóis Maranhenses National Park, Brazil

ABSTRACT Mouriri guianensis is a Brazilian endemic plant species distributed throughout the Amazon forest, Caatinga, Mata Atlântica and Cerrado domains, extending northward into Venezuela. The aim of this study was to describe the flowering phenology, floral biology and visitors associated with M. guianensis, highlighting the crepuscular bee species Megalopta amoena. Mouriri guianensis flowers from September to March. The flowering, the details of floral biology and the activities of floral visitors were observed for ten individual plants in December 2013, January-March 2014, September-December 2014 and January-March 2015. The flowering peaks occurred in December 2013 and in November-December 2014. Bees were collected in January and February 2015. A total of 86 individuals belonging to six bee species were recorded visiting the flowers, with Xylocopa cearensis making more than one-half of the visits (60%), followed by Melipona subnitida and Megalopta amoena with 21.17% and 9.41% of the visits, respectively. The visitors showed activity peaks between 5:00 and 6:00 AM (66.27%). Buzz pollination was their predominant behavior. Megalopta amoena used its jaws to open the pore and the anther gland. Melipona subnitida used parts of the glands to seal the entrance to the colony. The visitors, except for Augochlopsis sp. and Trigona sp., are pollinators of M. guianensis. Plants having an extended anthesis can attract visitors both day and night. In this study, we present an example of a crepuscular pollination system. We suggest that blooming at twilight is a strategy used by the plant to escape unsuitable visitors.

Essential oil constituents from high altitude Brazilian species with antimicrobial activity: Baccharis parvidentata Malag., Hyptis monticola Mart. ex Benth. and Lippia origanoides Kunth

The essential oils from three wild Brazilian plant species from high altitude were obtained by hydrodistillation and analyzed by GC/FID and GC/MS. The most noteworthy volatile compounds from Baccharis parvidentata were sabinene (15.2%), himachalol (10.3%), β-pinene (9.2%) and δ-3-carene (5.7%). The oil from Hyptis monticola was characterized predominantly by trans-caryophyllene (11.3%), (E)-methyl-cinnamate (7.8%), germacrene D (6.9%), limonene (6.6%), α-muurolene (6.4%) and β-pinene (5.6%) whereas the most prevalent components in the oil of Lippia origanoides were (E)-methyl cinnamate (40.0%), hedycaryol (8.0%), α-eudesmol (8.0%) and β-eudesmol (7.0%). Essential oils from B. parvidentata and L. origanoides displayed antibacterial and antifungal activities. Minimal inhibitory concentrations ranged from 78 μg/mL to 2500 μg/mL. Cryptococus neoformans and Trycophyton rubrum were the most sensitive microorganisms. The MIC and the microbicidal concentrations were identical. This is the first report on the chemical composition of Hyptis monticola and Baccharis parvidentata.

Activity of crude extracts from Brazilian cerrado plants against clinically relevant Candida species.

BackgroundMedicinal plants have traditionally been used in many parts of the world as alternative medicine. Many extracts and essential oils isolated from plants have disclosed biological activity, justifying the investigation of their potential antimicrobial activity. In this study, the in vitro antifungal activity of six Brazilian Cerrado medicinal plant species were evaluated against clinically relevant Candida species.MethodsThe crude extract plants were evaluated against American Type Culture Collection (ATCC) standard strains of Candida spp. using disk diffusion method and determining the minimum inhibitory concentration (MIC). The chemical study results were confirmed by HPLC method.ResultsAll six plant species showed antifungal activity. Among the species studied, Eugenia dysenterica and Pouteria ramiflora showed significant inhibitory activity against C. tropicalis at lowest MIC value of 125 and 500 μg/disc, respectively. The Eugenia dysenterica also disclosed MIC value of 125 μg/disc against C. famata, 250 μg/disc against C. krusei and 500 μg/disc against C. guilliermondii and C. parapsilosis. Pouteria torta, Bauhinia rufa, Erythroxylum daphnites and Erythroxylum subrotundum showed activity against the yeast strains with MIC value of 1000 μg/disc. The chemical study of the most bioactive extracts of Eugenia dysenterica and Pouteria ramiflora revealed catechin derivatives and flavonoids as main components.ConclusionsAll six evaluated plant species showed good antifungal potential against several Candida strains. However, E .dysenterica and P. ramiflora showed the higher inhibitory effect against the non-albicans Candida species. Our results may contribute to the continuing search of new natural occurring products with antifungal activity.

Fenologia reprodutiva e visitantes florais de Cordia superba Cham. (Boraginaceae) na vegetação da restinga de Grumari, Rio de Janeiro / Reproductive phenology and flower visitors of Cordia superba Cham. (Boraginaceae) in the restinga vegetation from Grumari, Rio de Janeiro

Cordia superba Cham. é uma espécie de planta arbustiva endêmica do Brasil, na Mata Atlântica e habita florestas ombrófilas e restingas. Nós determinamos a fenologia reprodutiva e os visitantes florais em indivíduos de C. superba na restinga Grumari, Rio de Janeiro, RJ. Iniciamos a pesquisa em fevereiro de 2012 e realizamos 26 amostragens, ao longo de um ano. Em seis indivíduos de C. superba foram consideradas diferentes estruturas para caracterizar as fenofases reprodutivas de floração e frutificação. Avaliamos se houve diferença significativa na presença de flores e frutos formados ao longo do ano utilizando o teste de Rayleigh (Z, p<0,05). As fenofases foram correlacionadas com a precipitação e a temperatura mensal média utilizando coeficiente de correlação de Pearson. A espécie apresentou floração contínua, anual e com duração prolongada e um pico da floração em abril de 2012 (Z= 17,03; p<0,01; r=0,47) e de frutificação em agosto de 2012 (Z=15,05; p<0,01; r=0,6). Apenas a frequência de botões florais foi correlacionada com a precipitação (r=0,69, p<0,05). As flores receberam visitas de seis insetos (três abelhas e três borboletas) das quais apenas duas abelhas realizaram visitas ilegítimas. Nossos resultados demonstram que C. superba apresentou um pico de floração definido na restinga. As visitas legítimas realizadas por abelhas e borboletas caracterizam uma polinização generalista para C. superba na área estudada.

In vitro antileishmanial activity of Brazilian plant species

Leishmaniasis is an infectious disease still widely spread in Brazil. It is a public health problem for the country due to its magnitude and geographic expansion leading to a complex, expensive and laborious control system [1, 2]. There is an urgent need to search for new medicines to treat leishmaniasis. Natural products can provide unlimited opportunities for the discovery of new lead compounds targeting this neglected disease. In this work, we investigated the antileishmanial activity of 22 plant extracts, from seven different species belonging to Apocynaceae, Asteraceae, Ebenaceae, Primulaceae and Rutaceae families. Samples were evaluated against promastigotes from L. infantum (strain BH46). The antileishmanial activity was measured 24h after exposition to the sample using the resazurin-based viability assay [3]. The toxicity of test samples is currently being investigated using dye exclusion method for cell viability using non-infected macrophages. According to preliminary results, four extracts from Aspidosperma spp. showed antileishmanial activity. The dichloromethane (DCM) extract from the stem showed an IC50 value of 89.5 ± 4.9 µg/mL. The IC50 of the remaining active extracts is currently being determined. The antileishmanial activity of this species will be further investigated, using intra- and extracellular parasite forms from other Leishmania species. The metabolic profiling and targeted isolation of bioactive constituents are in progress aiming for the identification of new lead compounds with antileishmanial activity.

Assessing the Chemical Composition and Antimicrobial Activity of Essential Oils from Brazilian Plants-Eremanthus erythropappus (Asteraceae), Plectrantuns barbatus, and P. amboinicus (Lamiaceae).

The chemical composition and antimicrobial activity of essential oils obtained from three Brazilian plant species—leaves and branches of Eremanthus erythropappus (Asteraceae), leaves of Plectranthus barbatus, and leaves of P. amboinicus (Lamiaceae)—were determined. Analysis by GC/MS and determination of Kovats indexes both indicated δ-elemene (leaves—42.61% and branches—23.41%) as well as (−)-α-bisabolol (leaves—24.80% and stem bark—66.16%) as major constituents of E. erythropappus essential oils. The main components of leaves of P. barbatus were identified as (Z)-caryophyllene (17.98%), germacrene D (17.35%), and viridiflorol (14.13%); whereas those of leaves of P. amboinicus were characterized as p-cymene (12.01%), γ-terpinene (14.74%), carvacrol (37.70%), and (Z)-caryophyllene (14.07%). The antimicrobial activity against yeasts and bacteria was assessed in broth microdilution assays to determine the minimum inhibitory concentration (MIC) necessary to inhibit microbial growth. In addition, the crude oil of branches of E. erythropappus was subjected to chromatographic separation procedures to afford purified (−)-α-bisabolol. This compound displayed biological activity against pathogenic yeasts, thus suggesting that the antimicrobial effect observed with crude oils of E. erythropappus leaves and branches may be related to the occurrence of (−)-α-bisabolol as their main component. Our results showed that crude oils of Brazilian plants, specifically E. erythropappus, P. barbatus, and P. amboinicus and its components, could be used as a tool for the developing novel and more efficacious antimicrobial agents.