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1.
Acta Parasitol ; 69(2): 1141-1147, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38568360

RESUMO

PURPOSE: Rhipicephalus (Boophilus) microplus is one the most significant ectoparasite in cattle farming in tropical and subtropical regions, causing problems to livestock health worldwide. The control of this ectoparasite primarily relies on the use of synthetic acaricides. However, the emergence of acaricide resistance has stimulated the search for new control alternatives, including phytocompounds with acaricidal and insecticidal potential. The aim of this study was to evaluate the acaricidal potential of Lavandula dentata essential oil against the engorged females of R. (B.) microplus. METHODS: Engorged females were obtained from infested bovines in dairy farms in Pernambuco, Brazil. L. dentata essential oil was extracted, and adult immersion test assays were performed using the following oil concentrations: 0.2%, 0.4%, 0.6%, 0.8%, and 1%. RESULTS: L. dentata essential oil at a concentration of 1% was lethal to all engorged females, and concentrations of 0.6% and 0.8% caused mortality of 98.6% and 99.1%, respectively. These concentrations disrupted the reproductive capacity of engorged females, reducing oviposition by more than 90% and preventing egg hatching by over 87%. CONCLUSION: The data revealed that L. dentata essential oil possesses effective pharmacological properties against R. (B.) microplus and could be used for tick control following in vivo evaluation, thus contributing to mitigating the negative impacts of synthetic acaricide use.


Assuntos
Acaricidas , Lavandula , Óleos Voláteis , Rhipicephalus , Animais , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Acaricidas/farmacologia , Acaricidas/química , Rhipicephalus/efeitos dos fármacos , Feminino , Lavandula/química , Brasil , Bovinos , Infestações por Carrapato/veterinária , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/parasitologia , Doenças dos Bovinos/parasitologia , Óleos de Plantas/farmacologia , Óleos de Plantas/química
2.
Data Brief ; 47: 108927, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36819901

RESUMO

Schinus terebinthifolius Raddi has been extensively studied due to its antioxidant, anti-inflammatory and antibiotic properties. Recently, its seeds have been tested against some insect pests as an insecticide, repellent and antifungal agent. Microencapsulation by spray-drying is widely used in the food and drug industries, as well as in the microencapsulation of essential oils, since it protects the oils against several effects, such as oxidation and thermal degradation, thus optimising its use. The aim was to microencapsulate S. terebinthifolius essential oil by spray-drying maltodextrin and arabic gum as encapsulating agents and SiO2 as a colloidal adjuvant. The morphology of the microcapsules was analysed by scanning electron microscopy (SEM), which evidenced mainly regular spherical-shaped particles with sizes between 5 and 10 µm. The thermal stability was studied by thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), and the microcapsules were stable at temperatures up to 200°C. The microencapsulating agents and the spray-drying technique produced microcapsules capable of protecting the essential oil against external effects, such as thermal degradation.

3.
Neotrop Entomol ; 51(4): 637-640, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35020182

RESUMO

A novel baculovirus observed to infect Automeris liberia (Cramer) (bullseye moth) is here described. Caterpillars of A. liberia with symptoms of viral infection were collected from African oil palm plantations in Tailândia, PA, Brazil. Macerated caterpillars were then offered to caterpillars of Automeris cinctistriga (Felder & Rogenhoper), leading to viral symptoms and death before pupation. A transmission electron microscope was used for virus ultrastructural identification. The presence of viral occlusion bodies (OBs) containing multiple nucleocapsids was observed and such features are compatible with Alphabaculovirus (Baculoviridae). Molecular detection by PCR with primers for polyhedrin gene (polh) and for late expression factor-8 gene (lef-8), confirmed that this isolate belonged to Alphabaculovirus genus. To our knowledge, this is the first record of a baculovirus isolated from or associated to Automeris. The name Automeris liberia nucleopolyhedrovirus (AuliNPV) is proposed for the new virus.


Assuntos
Lepidópteros , Mariposas , Nucleopoliedrovírus , Animais , Baculoviridae , Brasil , Libéria , Nucleopoliedrovírus/genética , Nucleopoliedrovírus/ultraestrutura , Filogenia
4.
Braz. arch. biol. technol ; 63: e20200206, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1132262

RESUMO

Abstract The high prevalence of anxiety disorders associated with pharmacotherapy side effects have motivated the search for new pharmacological agents. Species from Citrus genus, such as Citrus limon (sicilian lemon), have been used in folk medicine as a potential therapy to minimize emotional disorders. In order to searching for new effective treatments with fewer side effects, the present study evaluated the anxiolytic mechanism of action and the hypnotic-sedative activity from the Citrus limon fruit's peels essential oil (CLEO). Adults male Swiss mice were submitted to barbiturate-induced sleep test; elevated plus-maze (EPM) and light-dark box (LDB) (evaluation of the mechanism of action); rotarod; and catalepsy tests. CLEO oral treatment decreased latency and increased the sleep total time; moreover it induced in animals an increased the number of entries and percentage of time spent into open arms of the EPM; an increased the number of transitions and the percentage of time into light compartment in the LDB; which were only antagonized by flumazenil pretreatment, with no injury at motor function. Thus, results suggest that CLEO treatment induced an anxiolytic behavior suggestively modulated by the benzodiazepine binding site of the GABAA receptor or by an increase of GABAergic neurotransmission, without cause impairment in the motor coordination.


Assuntos
Animais , Masculino , Camundongos , Ansiedade/tratamento farmacológico , Ansiolíticos/uso terapêutico , Óleos Voláteis/uso terapêutico , Citrus/química , Moduladores GABAérgicos/farmacologia , Hipnóticos e Sedativos/uso terapêutico , Ansiolíticos/isolamento & purificação , Aprendizagem em Labirinto/efeitos dos fármacos , Hipnóticos e Sedativos/isolamento & purificação
5.
Arq. Inst. Biol ; 85: e0432017, 2018. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-999203

RESUMO

The weevil Ozopherus muricatus Pascoe, 1872 (Coleoptera: Curculionidae) is already considered a pest in Brazil for açaí palm (Euterpe oleracea Mart.) plantations. Its presence has become more frequent and caused significant reduction in the production of açaí fruit. Studies on the biology of this insect pest are still scarce, hindering its management. For studies on pheromones, for instance, it is essential to correctly identify the sex of the insect. The objective of this study was to evaluate the existence of sexual dimorphism in pupae and adults of O. muricatus in order to allow the identification of males and females. Larvae, pupae and adults were collected from açaí plantations and kept in biochemical oxygen demand (BOD) type incubation chambers. Adults and pupae were examined under a stereomicroscope, and dimorphism was determined through observation of external morphological characteristics. In addition, adults were dissected in order to observe genitalia and confirm the sex of specimens. In the pupae, sexual dimorphism was characterized by the presence of two protuberances in the terminal ventral region of the abdomen of females, which were absent in males. In adults, sexual dimorphism was also observed, based on the final abdominal segments. In males, it was possible to see all eight abdominal tergites, while in females tergite VIII is covered by tergite VII. Thus, the sexual dimorphism present in the morphological characteristics of O. muricatus allows the distinction between males and females of this species.(AU)


O gorgulho Ozopherus muricatus Pascoe, 1872 (Coleoptera: Curculionidae) já é considerado uma praga em plantações de açaí (Euterpe oleracea Mart.) no Brasil. Sua presença tem se tornado mais frequente e causado redução significativa na produção de frutos. Estudos sobre a biologia dessa praga ainda são escassos, dificultando o seu manejo. Para estudos com feromônios, por exemplo, é essencial a correta identificação do sexo do inseto. O objetivo deste estudo foi avaliar a existência de dimorfismo sexual em pupas e em adultos de O. muricatus, a fim de permitir a identificação de machos e fêmeas. Larvas, pupas e adultos foram coletados de plantações de açaí e mantidos em câmaras incubadoras para demanda bioquímica de oxigênio (DBO). Adultos e pupas foram examinados sob microscópio estereoscópico, e o dimorfismo foi determinado por meio da observação de características morfológicas externas. Adicionalmente, adultos foram dissecados para a observação da genitália e confirmação do sexo dos espécimes. Nas pupas, o dimorfismo sexual foi caracterizado pela presença de duas protuberâncias na região terminal ventral do abdome das fêmeas, as quais foram ausentes nos machos. Nos adultos, também se observou dimorfismo sexual, com base nos segmentos finais do abdome. Nos machos, é possível visualizar todos os oito tergitos abdominais, enquanto nas fêmeas o tergito VIII é encoberto pelo tergito VII. Assim, o dimorfismo sexual presente nas características morfológicas de O. muricatus permite distinção entre machos e fêmeas dessa espécie.(AU)


Assuntos
Besouros , Gorgulhos , Diferenciação Sexual , Euterpe
6.
Mem. Inst. Oswaldo Cruz ; 108(8): 974-982, 6/dez. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-697147

RESUMO

Infusions of Aspidosperma nitidum (Apocynaceae) wood bark are used to treat fever and malaria in the Amazon Region. Several species of this family are known to possess indole alkaloids and other classes of secondary metabolites, whereas terpenoids, an inositol and the indole alkaloids harmane-3 acid and braznitidumine have been described in A. nitidum . In the present study, extracts from the wood bark, leaves and branches of this species were prepared for assays against malaria parasites and cytotoxicity testing using human hepatoma and normal monkey kidney cells. The wood bark extracts were active against Plasmodium falciparum and showed a low cytotoxicity in vitro, whereas the leaf and branch extracts and the pure alkaloid braznitidumine were inactive. A crude methanol extract was subjected to acid-base fractionation aimed at obtaining alkaloid-rich fractions, which were active at low concentrations against P. falciparum and in mice infected with and sensitive Plasmodium berghei parasites. Our data validate the antimalarial usefulness of A. nitidum wood bark, a remedy that can most likely help to control malaria. However, the molecules responsible for this antimalarial activity have not yet been identified. Considering their high selectivity index, the alkaloid-rich fractions from the plant bark might be useful in the development of new antimalarials.


Assuntos
Animais , Humanos , Camundongos , Antimaláricos/farmacologia , Aspidosperma/química , Casca de Planta/química , Extratos Vegetais/farmacologia , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/isolamento & purificação , Malária/tratamento farmacológico , Malária/parasitologia , Testes de Sensibilidade Parasitária , Extratos Vegetais/isolamento & purificação
7.
Mem Inst Oswaldo Cruz ; 108(8): 974-82, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24402150

RESUMO

Infusions of Aspidosperma nitidum (Apocynaceae) wood bark are used to treat fever and malaria in the Amazon Region. Several species of this family are known to possess indole alkaloids and other classes of secondary metabolites, whereas terpenoids, an inositol and the indole alkaloids harmane-3 acid and braznitidumine have been described in A. nitidum . In the present study, extracts from the wood bark, leaves and branches of this species were prepared for assays against malaria parasites and cytotoxicity testing using human hepatoma and normal monkey kidney cells. The wood bark extracts were active against Plasmodium falciparum and showed a low cytotoxicity in vitro, whereas the leaf and branch extracts and the pure alkaloid braznitidumine were inactive. A crude methanol extract was subjected to acid-base fractionation aimed at obtaining alkaloid-rich fractions, which were active at low concentrations against P. falciparum and in mice infected with and sensitive Plasmodium berghei parasites. Our data validate the antimalarial usefulness of A. nitidum wood bark, a remedy that can most likely help to control malaria. However, the molecules responsible for this antimalarial activity have not yet been identified. Considering their high selectivity index, the alkaloid-rich fractions from the plant bark might be useful in the development of new antimalarials.


Assuntos
Antimaláricos/farmacologia , Aspidosperma/química , Casca de Planta/química , Extratos Vegetais/farmacologia , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/isolamento & purificação , Humanos , Concentração Inibidora 50 , Malária/tratamento farmacológico , Malária/parasitologia , Camundongos , Testes de Sensibilidade Parasitária , Extratos Vegetais/isolamento & purificação
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