Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Plant J ; 108(6): 1662-1678, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34624152

RESUMO

Wintersweet (Chimonanthus praecox) is one of the most important ornamental plants. Its color is mainly determined by the middle tepals. However, the molecular mechanisms underlying the intriguing flower color development among different wintersweet groups are still largely unknown. In addition, wintersweet belongs to magnoliids, and the phylogenetic position of magnoliids remains to be determined conclusively. Here, the whole genome of red flower wintersweet, a new wintersweet type, was sequenced and assembled with high quality. The genome comprised 11 super-scaffolds (chromosomes) with a total size of 737.03 Mb. Based on the analyses of the long branch attraction, incomplete lineage sorting, sparse taxon sampling, and other factors, we suggest that a bifurcating tree may not fully represent the complex early diversification of the angiosperms and that magnoliids are most likely sister to the eudicots. The wintersweet genome appears to have undergone two whole-genome duplication (WGD) events: a recent WGD event representing an independent event specific to the Calycanthaceae and an ancient WGD event shared by Laurales. By integrating genomic, transcriptomic, and metabolomic data, CpANS1 and the transcription factor CpMYB1 were found to play key roles in regulating tepal color development, whereas CpMYB1 needs to form a complex with bHLH and WD40 to fully perform its regulatory function. The present study not only provides novel insights into the evolution of magnoliids and the molecular mechanism for flower color development, but also lays the foundation for subsequent functional genomics study and molecular breeding of wintersweet.


Assuntos
Calycanthaceae/fisiologia , Flores/fisiologia , Pigmentação/fisiologia , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Antocianinas/genética , Antocianinas/metabolismo , Calycanthaceae/genética , Flores/genética , Mutação da Fase de Leitura , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Laurales/genética , Laurales/fisiologia , Anotação de Sequência Molecular , Filogenia , Pigmentação/genética , Sequenciamento Completo do Genoma
2.
Food Chem Toxicol ; 156: 112445, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34332013

RESUMO

This study aimed to evaluate the effect of Chimonanthus nitens Oliv. essential oil (named CEO) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats. In the present study, 21 compounds were characterized in CEO by gas chromatography-mass spectrometry analysis. Furthermore, animal data suggested that CEO could protect rats against ALI, as evidence by increasing white blood cell count, reducing immune organ index and improving lung histopathological changes in rats subjected to LPS. Reduction of the levels of IL-1ß was also shown during CEO-triggering lung protection in rats. Meanwhile, these protective effects of CEO were accompanied by the attenuation of lipid oxidation, and elevation of antioxidant enzymes, suggesting that enhancement of antioxidant defense was linked to its lung protection. Moreover, a combination with CEO and LPS significantly elevated short-chain fatty acids (SCFAs) compared with LPS alone via increasing propionic, i-butyric, butyric and i-valeric acid on LPS-induced ALI in rats. Therefore, our findings indicated that CEO could alleviate LPS-caused ALI in rats by controlling aberrant inflammation, correcting the redox system, and modulating SCFAs in rats.


Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Laurales/química , Lipopolissacarídeos/toxicidade , Óleos Voláteis/farmacologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Animais , Citocinas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Óleos Voláteis/análise , Ratos , Ratos Wistar , Baço/efeitos dos fármacos , Timo/efeitos dos fármacos
3.
Molecules ; 26(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063513

RESUMO

Chemical compositions of plants are affected by the initial nutrient contents in the soil and climatic conditions; thus, we analyzed for the first time the effects of soil and leaf nutrients on the compositions of the essential oils (EOs) of Siparuna muricata in four different localities in Ecuador. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and a gas chromatography/flame ionization detector (GC/FID). Enantiomeric distribution by GC/MS was determined, modifying the enantiomeric separation of ß-pinene, limonene, δ-elemene, ß-bourbonene, cis-cadina-1 (6), 4-diene and atractylone. A total of 44 compounds were identified. The most representative for L1 were guaiol, atractylone and 4-diene; for L2, cis-cadina-1(6),4-diene and myrcene; for L3, atractylone, myrcene and germacrene B; and finally, L4 germacrene B, myrcene and cis-cadina-1(6),4-diene. Correlations between soil- leaf chemical elements such as Al, Ca, Fe, Mg, Mn, N and Si in the different localities were significant with chemical composition of the essential oil of Siparuna muricata; however, correlations between soil and leaf K, P, and Na were not significant. Cluster and NMDS analysis showed high dissimilarity values of secondary metabolites between four localities related with changes in soil- leaf nutrients. Thus, the SIMPER routine revealed that not all secondary metabolites contribute equally to establishing the differences in the four localities, and the largest contributions are due to differences in guaiol, cis-cadina-1(6),4-diene, atractylone and germacrene. Our investigation showed for the first time the influences of altitude and soil- leaf chemical elements in the chemical composition of the EOs of S. muricata.


Assuntos
Laurales/química , Óleos de Plantas/química , Solo/química , Monoterpenos Bicíclicos/análise , Equador , Ionização de Chama , Cromatografia Gasosa-Espectrometria de Massas , Limoneno/análise , Óleos Voláteis/química , Folhas de Planta/química , Metabolismo Secundário , Sesquiterpenos/análise
4.
Molecules ; 26(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806970

RESUMO

Most insecticides commonly used in storage facilities are synthetic, an issue that generates concerns about food safety and public health. Therefore, the development of eco-friendly pest management tools is urgently needed. In the present study, a 6% (w/w) Hazomalania voyronii essential oil-based nanoemulsion (HvNE) was developed and evaluated for managing Tribolium confusum, T. castaneum, and Tenebrio molitor, as an eco-friendly wheat protectant. Larval and adult mortality was evaluated after 4, 8, and 16 h, and 1, 2, 3, 4, 5, 6, and 7 days, testing two HvNE concentrations (500 ppm and 1000 ppm). T. confusum and T. castaneum adults and T. molitor larvae were tolerant to both concentrations of the HvNE, reaching 13.0%, 18.7%, and 10.3% mortality, respectively, at 1000 ppm after 7 days of exposure. However, testing HvNE at 1000 ppm, the mortality of T. confusum and T. castaneum larvae and T. molitor adults 7 days post-exposure reached 92.1%, 97.4%, and 100.0%, respectively. Overall, the HvNE can be considered as an effective adulticide or larvicide, depending on the target species. Our results highlight the potential of H. voyronii essential oil for developing green nanoinsecticides to be used in real-world conditions against key stored-product pests.


Assuntos
Inseticidas , Laurales/química , Óleos Voláteis , Tribolium/crescimento & desenvolvimento , Triticum/parasitologia , Animais , Emulsões , Inseticidas/química , Inseticidas/farmacologia , Larva/crescimento & desenvolvimento , Óleos Voláteis/química , Óleos Voláteis/farmacologia
5.
Exp Parasitol ; 223: 108079, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33524381

RESUMO

Chagas disease is caused by Trypanosoma cruzi, and it is an important cause of morbidity and mortality in Latin America. There are no vaccines, and the chemotherapy available to treat this infection has serious side effects. In a search for alternative treatments, we determined the in vitro susceptibility of epimastigote and trypomastigote forms of T. cruzi and the cytotoxic effects on peripheral blood mononuclear cells (PBMCs) of ethanolic extracts obtained from six different plant species. The ethanolic extracts of Ageratina vacciniaefolia, Clethra fimbriata and Siparuna sessiliflora showed antiprotozoal activity against epimastigotes and low cytotoxicity in mammalian cells. However, only the ethanolic extract of C. fimbriata showed activity against T. cruzi trypomastigotes, and it had low cytotoxicity in PBMCs. An analysis on the phytochemical composition of C. fimbriata extract showed that its metabolites were primarily represented by two families of compounds: flavonoids and terpenoids. Lastly, we analyzed whether the A. vacciniaefolia, C. fimbriata, or S. sessiliflora ethanolic extracts induced IFN-γ or TNF-α production. Significantly, ethanolic extracts of C. fimbriata induced TNF-α production and S. sessiliflora induced both cytokines. In addition, C. fimbriata and S. sessiliflora induced the simultaneous secretion of IFN-γ and TNF-α in CD8+ T cells. The antiprotozoal and immunomodulatory activity of C. fimbriata may be related to the presence of flavonoid and triterpene compounds in the extract. Thus, these findings suggest that C. fimbriata may represent a valuable source of new bioactive compounds for the therapeutic treatment of Chagas disease that combines trypanocidal activity with the capacity to boost the immune response.


Assuntos
Doença de Chagas/tratamento farmacológico , Leucócitos Mononucleares/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Adulto , Ageratina/química , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Cromatografia Líquida de Alta Pressão , Clethraceae/química , Colômbia , Feminino , Citometria de Fluxo , Humanos , Concentração Inibidora 50 , Interferon gama/metabolismo , Laurales/química , Masculino , Medicina Tradicional , Extratos Vegetais/toxicidade , Espectrometria de Massas por Ionização por Electrospray , Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
6.
J Ethnopharmacol ; 270: 113788, 2021 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-33429033

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Siparuna species are used in Brazilian Folk Medicine for the treatment and prophylaxis of colds, fever, headache, gastrointestinal disorders and rheumatic pain. AIM OF THE STUDY: This study aimed to investigate a possible anti-influenza activity of 25 extracts from leaves of Amazonian S. cristata, S. decipiens, S. glycycarpa, S. reginae and S. sarmentosa based on their folk medicinal uses as well as to investigate their metabolic fingerprinting. The chemical composition of the active extracts was further dereplicated. MATERIAL AND METHODS: The chemical composition of the crude EtOH extracts from five Siparuna species were investigated by ESI (±) LC-QTOF-MS2. Organic extracts were obtained by liquid-liquid partition with solvents of increasing polarity, generating 25 extracts which were subjected to a quick DI-ESI (±) IT-MS fingerprint analysis. These extracts were tested against influenza virus replication and cellular toxicity using MDCK cells and influenza A/Michigan/45/2015 (H1N1)pdm09 virus. The compounds in the active BuOH extracts from S. glycycarpa and S. sarmentosa were annotated by ESI (±) LC-QTOF-MS2. RESULTS: Analysis of the EtOH extracts revealed the presence of alkaloids and flavonoids, in the positive and negative ionization modes. Out of the 25 organic extracts screened for their antiviral activity, the BuOH extracts from S. glycycarpa and S. sarmentosa were the most active, inhibiting 96.0 ± 1.3% and 89.5 ± 0.8% of influenza virus replication 24 h post-infection. These inhibitory effects were maintained until 72hpi. Alkaloids, O- and C-flavonoid glycosides, dihydrochalcones and a procyanidin dimer were annotated in these extracts. CONCLUSIONS: The inhibitory effect against influenza A(H1N1)pdm09 virus replication shown by Amazonian Siparuna species corroborates the use of these plants in Brazilian Folk Medicine, showing their potential as anti-influenza agents. These promising results stimulate the continuation of this study with the aim of isolating the compound(s) responsible for this bioactivity, thus contributing to a better knowledge of those species and to the research of natural products with potential anti-influenza activity.


Assuntos
Antivirais/química , Antivirais/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Laurales/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Antivirais/análise , Biflavonoides/química , Biflavonoides/farmacologia , Brasil , Catequina/química , Catequina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cães , Flavonoides/química , Flavonoides/farmacologia , Células Madin Darby de Rim Canino , Medicina Tradicional , Extratos Vegetais/análise , Proantocianidinas/química , Proantocianidinas/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
7.
J Ethnopharmacol ; 265: 113344, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32890711

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Siparuna guianensis Aublet leaves, known as negramina, are used by indigenous and local communities in Brazil and other countries in the Americas to treat pain and inflammatory diseases. AIM OF THE STUDY: To characterize the chemical constituents and to evaluate the antioxidant, anti-inflammatory, antinociceptive and locomotor activities of the dichloromethane fraction (DF) of S. guianensis leaves. Also, an acute oral toxicity test was accomplished. MATERIAL AND METHODS: The chemical characterization of DF was performed by ultra-high pressure liquid chromatography (UHPLC) analyses coupled with a high-resolution mass spectrometer. The antioxidant potential of DF was investigated using nitric oxide (NO) and hydroxyl radical (OH) scavenging test. The evaluation study of the anti-inflammatory activity was carried out in vitro by NO measurement in stimulated macrophages and, in vivo, by croton oil-induced ear edema, LPS-induced peritonitis, and zymosan-induced arthritis in mice. Different mechanisms of central and peripheral nociception were stimulated by acetic acid-induced writhing, formalin, and tail-flick tests. Besides that, the open field assay was performed. RESULTS: UHPLC analyses of DF showed the presence of a mixture of glycosylated and methoxylated flavonoids. DF was able to scavenge NO and OH radicals in vitro and showed anti-inflammatory activity by inhibiting NO production in LPS-stimulated murine macrophages. Oral administration of DF considerably inhibited the ear edema after croton oil application and reduced the leukocyte infiltrated in LPS-induced peritonitis. In the inflammatory intra-articular zymosan-induced process, DF showed a significant reduction in the inflammatory area and of the cells in the synovial and connective tissues adjacent to the joint. Also, DF was able to reduce the intra-articular edema. In nociception models, the oral administration of DF considerably inhibited the acetic acid-induced writhings. The formalin test showed that DF attenuated the licking time in both phases, which suggested that DF reduce the nociception by central and peripheral mechanisms. In the tail-flick test, DF showed no activity. Besides that, DF did not affect the animal locomotion, and no acute toxicity was observed. CONCLUSIONS: For the first time, the anti-inflammatory and antinociceptive activities of S. guianensis were reported, supporting its ethnopharmacological uses for some inflammatory diseases and painful conditions.


Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios/farmacologia , Laurales/química , Extratos Vegetais/farmacologia , Analgésicos/isolamento & purificação , Animais , Anti-Inflamatórios/isolamento & purificação , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Brasil , Modelos Animais de Doenças , Edema/tratamento farmacológico , Locomoção/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Masculino , Medicina Tradicional , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Nociceptividade/efeitos dos fármacos , Dor/tratamento farmacológico , Medição da Dor
8.
Molecules ; 25(18)2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32927887

RESUMO

In a series of anti-inflammatory screenings of lauraceous plants, the methanolic extract of the leaves of Machilus japonica var. kusanoi (Hayata) J.C. Liao showed potent inhibition on both superoxide anion generation and elastase release in human neutrophils. Bioassay-guided fractionation of the leaves of M. japonica var. kusanoi led to the isolation of twenty compounds, including six new butanolides, machinolides A-F (1-6), and fourteen known compounds (7-20). Their structures were characterized by 1D and 2D NMR, UV, IR, CD, and MS data. The absolute configuration of the new compounds were unambiguously confirmed by single-crystal X-ray diffraction analyses (1, 2, and 3) and Mosher's method (4, 5, and 6). In addition, lignans, (+)-eudesmin (11), (+)-methylpiperitol (12), (+)-pinoresinol (13), and (+)-galbelgin (16) exhibited inhibitory effects on N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation in human neutrophils with IC50 values of 8.71 ± 0.74 µM, 2.23 ± 0.92 µM, 6.81 ± 1.07 µM, and 7.15 ± 2.26 µM, respectively. The results revealed the anti-inflammatory potentials of Formosan Machilus japonica var. kusanoi.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Laurales/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Anti-Inflamatórios/uso terapêutico , Humanos , Estrutura Molecular , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/química , Extratos Vegetais/farmacologia
9.
Molecules ; 25(17)2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32854178

RESUMO

The essential oil of Siparuna guianensis was obtained by hydrodistillation. The identification of the chemical compounds was performed by gas chromatography coupled with mass spectrometry (GC/MS). Antimicrobial activity was investigated for four microorganisms: Streptococcus mutans (ATCC 3440), Enterococcus faecalis (ATCC 4083), Escherichia coli (ATCC 25922), and Candida albicans (ATCC-10231). The studies of doping and molecular dynamics were performed with the molecule that presented the highest concentration of drug-target proteins, 1IYL (C. albicans), 1C14 (E. coli), 2WE5 (E. faecalis), and 4TQX (S. mutans). The main compounds identified were: Curzerene (7.1%), γ-Elemene (7.04%), Germacrene D (7.61%), trans-ß-Elemenone (11.78%), and Atractylone (18.65%). Gram positive bacteria and fungi were the most susceptible to the effects of the essential oil. The results obtained in the simulation showed that the major compound atractylone interacts with the catalytic sites of the target proteins, forming energetically favourable systems and remaining stable during the period of molecular dynamics.


Assuntos
Anti-Infecciosos , Bactérias/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Laurales/química , Simulação de Acoplamento Molecular , Óleos Voláteis , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia
10.
J Med Entomol ; 57(3): 788-796, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-31840745

RESUMO

Siparuna guianensis (Laurales: Siparunaceae) has a terpene-rich essential oil with great potential for larvicides. The poor water miscibility of their compounds makes nano-emulsions of great interest for novel bioactive systems, including for control of Aedes aegypti (Diptera: Culicidae). This species is adapted to urban environments with important role in the epidemiology of some arboviruses such as dengue, chikungunya fever, zika, and urban yellow fever. The aim of the present study was to evaluate the feasibility of nano-emulsification to affect Ae. aegypti larvae. An optimal system was achieved by using a nonionic single surfactant, highlighted by its satisfactory size distribution profile. Moreover, improved larvicidal activity in comparison to bulk essential oil can be observed for the nano-emulsions. The estimated LC50 and LC90 values after 24 h of treatment of larvae with the essential oil were, respectively, 86.5232 and 134.814 µg/ml, while the estimated LC50 and LC90 value after treatment with the nano-emulsion were 24.7572 and 75.2452 µg/ml, respectively. The utilization of a simple technique to produce a fine nano-emulsion opens perspective for further integrative practices of mosquito control and giving value to this Amazon plant species may encourage its sustainable use and contribute to conservation policies.


Assuntos
Aedes , Inseticidas/análise , Laurales/química , Óleos Voláteis/química , Animais , Formas de Dosagem , Dose Letal Mediana , Nanoestruturas , Óleos Voláteis/administração & dosagem
11.
Genes (Basel) ; 10(11)2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703401

RESUMO

Chimonanthus campanulatus R.H. Chang & C.S. Ding is a good horticultural tree because of its beautiful yellow flowers and evergreen leaves. In this study, fluorescence in situ hybridization (FISH) was used to analyse mitotic metaphase chromosomes of Ch. campanulatus with 5S rDNA and (AG3T3)3 oligonucleotides. Twenty-two small chromosomes were observed. Weak 5S rDNA signals were observed only in proximal regions of two chromosomes, which were adjacent to the (AG3T3)3 proximal signals. Weak (AG3T3)3 signals were observed on both chromosome ends, which enabled accurate chromosome counts. A pair of satellite bodies was observed. (AG3T3)3 signals displayed quite high diversity, changing in intensity from weak to very strong as follows: far away from the chromosome ends (satellites), ends, subtelomeric regions, and proximal regions. Ten high-quality spreads revealed metaphase dynamics from the beginning to the end and the transition to anaphase. Chromosomes gradually grew larger and thicker into linked chromatids, which grew more significantly in width than in length. Based on the combination of 5S rDNA and (AG3T3)3 signal patterns, ten chromosomes were exclusively distinguished, and the remaining twelve chromosomes were divided into two distinct groups. Our physical map, which can reproduce dynamic metaphase progression and distinguish chromosomes, will powerfully guide cytogenetic research on Chimonanthus and other trees.


Assuntos
Cromossomos de Plantas/genética , Laurales/genética , Metáfase/genética , RNA Ribossômico 5S/genética , Hibridização in Situ Fluorescente/métodos , Mapeamento Físico do Cromossomo/métodos
12.
Environ Pollut ; 255(Pt 1): 113153, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520906

RESUMO

Plant essential oils are regarded as interesting alternative tools to be integrated into the management of pest insects. However, as they generally consist of mixtures of numerous molecules, the physiological basis for their action is unresolved. Here, we evaluated the effects of essential oil of the Neotropical plant Siparuna guianensis Aubl., commonly known as Negramina, against an important pest insect: the green peach aphid Myzus persicae (Sulzer), and also in two non-target natural enemies: the ladybeetle predators Coleomegilla maculata (DeGeer) and Eriopis connexa (Germar). In addition, we conducted a computational docking analysis for predicting the physical interactions between the two Negramina essential oil major constituents: ß-myrcene and 2-undocanone, and the transient receptor potential (TRP) channels as potential binding receptors in the aphid and ladybeetles. As the most important results, Negramina essential oil caused mortality in M. persicae aphids with an LC95 = 1.08 mg/cm2, and also significantly repelled the aphids at concentrations as low as 0.14 mg/cm2. Our computational docking analysis reinforced such selectivity actions as the Negramina essential oil major compounds (i.e., ß-myrcene and 2-undocanone) bound to the TRP channels of M. persicae but not to ladybeetle-related TRP channels. Interestingly, the exposure to the Negramina essential oil did not affect the predatory abilities of C. maculata but increased the abilities of E. connexa to prey upon M. persicae. Collectively, our findings provided a physiological basis for the insecticidal and selectivity potential of Negramina essential oil, reinforcing its potential as a tool to be used in integrated pest control programs.


Assuntos
Afídeos/efeitos dos fármacos , Besouros/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Laurales/química , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Monoterpenos Acíclicos/análise , Animais , Óleos Voláteis/química , Óleos de Plantas/química
13.
PLoS Negl Trop Dis ; 13(8): e0007624, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398198

RESUMO

BACKGROUND: The use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate. RESULTS: We assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles. CONCLUSIONS: The encapsulation of S. guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae. aegypti.


Assuntos
Aedes/efeitos dos fármacos , Quitosana/química , Larva/efeitos dos fármacos , Laurales/química , Nanopartículas/química , Óleos Voláteis/farmacologia , Aedes/crescimento & desenvolvimento , Animais , Brasil , Controle de Insetos/métodos , Inseticidas/farmacologia , Larva/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Mosquitos Vetores/efeitos dos fármacos , Extratos Vegetais/farmacologia
14.
Sci Rep ; 8(1): 7215, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29740112

RESUMO

Although the cultivation of transgenic plants expressing toxins of Bacillus thuringiensis (Bt) represents a successful pest management strategy, the rapid evolution of resistance to Bt plants in several lepidopteran pests has threatened the sustainability of this practice. By exhibiting a favorable safety profile and allowing integration with pest management initiatives, plant essential oils have become relevant pest control alternatives. Here, we assessed the potential of essential oils extracted from a Neotropical plant, Siparuna guianensis Aublet, for improving the control and resistance management of key lepidopteran pests (i.e., Spodoptera frugiperda and Anticarsia gemmatalis). The essential oil exhibited high toxicity against both lepidopteran pest species (including an S. frugiperda strain resistant to Cry1A.105 and Cry2Ab Bt toxins). This high insecticidal activity was associated with necrotic and apoptotic effects revealed by in vitro assays with lepidopteran (but not human) cell lines. Furthermore, deficits in reproduction (e.g., egg-laying deterrence and decreased egg viability), larval development (e.g., feeding inhibition) and locomotion (e.g., individual and grouped larvae walking activities) were recorded for lepidopterans sublethally exposed to the essential oil. Thus, by similarly and efficiently controlling lepidopteran strains susceptible and resistant to Bt toxins, the S. guianensis essential oil represents a promising management tool against key lepidopteran pests.


Assuntos
Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Laurales/química , Mariposas/efeitos dos fármacos , Óleos Voláteis/farmacologia , Spodoptera/efeitos dos fármacos , Animais , Bacillus thuringiensis/química , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/farmacologia , Linhagem Celular , Endotoxinas/isolamento & purificação , Endotoxinas/farmacologia , Proteínas Hemolisinas/isolamento & purificação , Proteínas Hemolisinas/farmacologia , Inseticidas/isolamento & purificação , Larva/efeitos dos fármacos , Larva/fisiologia , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Mariposas/fisiologia , Óleos Voláteis/isolamento & purificação , Controle Biológico de Vetores/métodos , Spodoptera/fisiologia , Zigoto/efeitos dos fármacos , Zigoto/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...