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1.
Exp Parasitol ; 250: 108542, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37178971

RESUMO

Although new nematicides have appeared, the demand for new products less toxic and more efficient for the control of plant-parasitic nematodes are still high. Consequently, studies on natural secondary metabolites from plants, to develop new nematicides, have increased. In this work, nineteen extracts from eleven Brazilian plant species were screened for activity against Meloidogyne incognita. Among them, the extracts of Piterogyne nitens showed a potent nematostatic activity. The alkaloid fraction obtained from the ethanol extract of leaves of P. nitens was more active than the coming extract. Due to the promising activity from the alkaloid fraction, three isoprenylated guanidine alkaloids isolated from this fraction, galegine (1), pterogynidine (2), and pterogynine (3) were tested, showing similar activity to the alkaloid fraction, which was comparable to that of the positive control Temik at 250 µg/mL. At lower concentrations (125-50 µg/mL), compound 2 showed to be the most active one. As several nematicides act through inhibition of acetylcholinesterase (AChE), the guanidine alkaloids were also employed in two in vitro AChE assays. In both cases, compound 2 was more active than compounds 1 and 3. Its activity was considered moderated compared to the control (physostigmine). Compound 2 was selected for an in silico study with the electric eel (Electrophorus electricus) AChE, showing to bind mostly to the same site of physostigmine in the AChEs, pointing out that this could be the mechanism of action for this compound. These results suggested that the guanidine alkaloids 1,2 and 3 from P. nitens are promising for the development of new products to control M. incognita, especially guanidine 2, and encourage new investigations to confirm the mechanism of action, as well as to determine the structure-activity relationship of the guanidine alkaloids.


Assuntos
Alcaloides , Fabaceae , Acetilcolinesterase , Guanidina/farmacologia , Fisostigmina , Alcaloides/farmacologia , Extratos Vegetais/farmacologia , Guanidinas/farmacologia , Antinematódeos/farmacologia , Inibidores da Colinesterase/farmacologia
2.
Plant Dis ; 107(8): 2352-2358, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37552644

RESUMO

The demand for new soil fumigants has increased as a result of more restrictive legislation regarding the use of pesticides. In the present study, the potent nematicidal activity of volatile organic compounds released by the Annona muricata leaf macerate was demonstrated. In addition, we searched in the A. muricata volatilome for a molecule with potential to be developed as a new fumigant nematicide. In the greenhouse, even the lowest concentration of soursop leaf macerate tested (1.0%) as a biofumigant caused a significant (P < 0.05) reduction in Meloidogyne incognita infectivity and reproduction when compared with the nontreated control (0%). Forty-one compounds were identified through gas chromatography-mass spectrometry analysis, of which three (sabinene, caryophyllene oxide, and 4-ethylbenzaldehyde) were selected for studies against the nematode. Among these compounds, in in vitro trails, only 4-ethylbenzaldehyde showed nematicidal activity at 250 µg ml-1. The effective doses of 4-ethylbenzaldehyde predicted to kill 50 and 95% of the M. incognita second-stage juvenile population after 48 h of exposure were 35 and 88 µg ml-1, respectively. In in vitro tests, 4-ethylbenzaldehyde at 150 µg ml-1 reduced M. incognita egg hatching to values similar (P > 0.05) to those of the commercial nematicide fluensulfone at a concentration of 200 µg ml-1. In plant experiments, as a soil fumigant, 4-ethylbenzaldehyde at a dose of 1 ml/liter of substrate had an effect similar (P > 0.05) to that of the commercial fumigant Dazomet (250 µg ml-1). Therefore, 4-ethylbenzaldehyde shows potential for development as a new nematicide.


Assuntos
Annona , Praguicidas , Tylenchoidea , Animais , Antinematódeos/farmacologia , Antinematódeos/química , Praguicidas/farmacologia , Solo/química
3.
Exp Parasitol ; 241: 108359, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35998723

RESUMO

To contribute to the development of new fumigant nematicides for the control of the plant-parasitic nematode Meloidogyne incognita, this study started with 31 volatile organic compounds reported as toxic to nematodes. At 500 µg/mL, α-ionone, (S)-carvone, (R)-carvone, 2-methylpropyl acetate, undecan-2-one, decan-2-one, and dodecan-2-one caused mortalities to M. incognita second-stage juveniles (J2) that were similar to those obtained with the commercial nematicides carbofuran (170 µg/mL) and fluensulfone (42.2 µg/mL). (R)-carvone, with a lethal concentration to 50% J2 (LC50) equal to 524 µg/mL, was selected for subsequent studies. When J2 were exposed to the (R)-carvone solution, the infectivity and reproduction on tomato were reduced. In the M. incognita egg hatching assay, (R)-carvone behaved like a true ovicide. When employed as a fumigant, (R)-carvone (3.9 g/L) was as efficient as the soil fumigant dazomet (0.245 g/L) in eliminating eggs of the nematode in a substrate to be used for tomato planting. According to in silico studies employing pharmacophoric searches and molecular docking, acetylcholinesterases are the target of (R)-carvone in the nematode.


Assuntos
Solanum lycopersicum , Tylenchoidea , Acetilcolinesterase , Animais , Antinematódeos/química , Antinematódeos/farmacologia , Monoterpenos Cicloexânicos , Solanum lycopersicum/parasitologia , Simulação de Acoplamento Molecular , Solo
4.
J Nematol ; 54(1): 20220031, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36338428

RESUMO

As a result of more restrictive legislation regarding the use of pesticides, over the last two decades, the demand for new soil fumigants has increased. These compounds can come from a variety of sources, including organic residues. In this study, we identified in the cassava wastewater volatiloma a molecule with potential to be developed as a new fumigant nematicide. Cassava wastewater (20 mL) releases volatile compounds toxic to Meloidogyne javanica second-stage juveniles (J2), causing J2 mortality up to 89%. Through gas chromatography-mass spectrometry, eight compounds were identified in the cassava wastewater volatiloma, with alcohols being the major class. The compounds ethyl butanoate and butyric acid identified in cassava wastewater volatiloma were selected for in vitro nematicidal activities and substrate fumigation tests. The lethal concentration predicted LC50-48 hr values (effective doses to kill 50% of M. javanica J2 population after 48 h of exposure) were 172.6 µg ∙ mL - 1 and 301.2 µg ∙ mL - 1 for butyric acid and ethyl butanoate, respectively. In a pot assay, the application of butyric acid and ethyl butanoate as a soil fumigant, at a dose of 0.5 mL ∙ kg - 1 substrate, significantly (P < 0.05) decreased M. javanica infectivity and reproduction compared to the negative control (water). However, ethyl butanoate proved to be a more efficient soil fumigant (P < 0.05) than butyric acid, as its application reduced the number of galls and eggs to the level of the commercial fumigant Dazomet. This study is the first to demonstrate the potential of ethyl butanoate as a soil fumigant against M. javanica.

5.
J Nematol ; 54(1): 20220013, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35860510

RESUMO

Meloidogyne enterolobii and M. floridensis are virulent species that can overcome root-knot nematode resistance in economically important crops. Our objectives were to determine the effects of temperature on the infectivity of second-stage juveniles (J2) of these two species and determine differences in duration and thermal-time requirements (degree-days [DD]) to complete their developmental cycle. Florida isolates of M. enterolobii and M. floridensis were compared to M. incognita race 3. Tomato cv. BHN 589 seedlings following inoculation were placed in growth chambers set at constant temperatures of 25°C, and 30°C, and alternating temperatures of 30°C to 25°C (day-night). Root infection by the three nematode species was higher at 30°C than at 25°C, and intermediate at 30°C to 25°C, with 33%, 15%, and 24% infection rates, respectively. There was no difference, however, in the percentages of J2 that infected roots among species at each temperature. Developmental time from infective J2 to reproductive stage for the three species was shorter at 30°C than at 25°C, and 30°C to 25°C. The shortest time and DD to egg production for the three species were 13 days after inoculation (DAI) and 285.7 DD, respectively. During the experimental timeframe of 29 d, a single generation was completed at 30°C for all three species, whereas only M. floridensis completed a generation at 30°C to 25°C. The number of days and accumulated DD for completing the life cycle (from J2 to J2) were 23 d and 506.9 DD for M. enterolobii, and 25 d and 552.3 DD for M. floridensis and M. incognita, respectively. Exposure to lower (25°C) and intermediate temperatures (30°C to 25°C) decreased root penetration and slowed the developmental cycle of M. enterolobii and M. floridensis compared with 30°C.

6.
J Nematol ; 532021.
Artigo em Inglês | MEDLINE | ID: mdl-34337424

RESUMO

New management tools are necessary to reduce the damage caused by the soybean cyst nematode (SCN), Heterodera glycines. Identification of molecules that can stimulate second-stage juveniles (J2) hatching in an environment without food may contribute to that. In in vitro experiments, we evaluate the effect of volatile organic compounds (VOCs) released by soybean (Glycine max), bean (Phaseolus vulgaris), ryegrass (Lolium multiflorum), and alfalfa (Medicago sativa) on H. glycines egg hatching. VOCs released by all plant species significantly (p < 0.05) increased egg hatching. Short-chain molecules released by leaves and roots of soybean and bean increased the hatching up to 71.4%. The analysis of the volatilome done by gas chromatography coupled with mass spectrometry revealed 44 compounds in the plant emissions. Four of them, namely 3-octanol, 1-hexanol, hexanal and linalool were tested individually as hatching inductors. Under concentrations of 200, 600, and 1,000 µg/ml there was no hatching induction of H. glycines J2 by these compounds. On the other hand, in these concentrations, the compounds 3-octanol and 1-hexanol caused hatching reduction with values similar to the commercial nematicide carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methyl carbamate). In subsequent tests, the compounds 1-hexanol and 3-octanol showed lethal concentration values required to kill 50% of thenematode population (LC50) of 210 and 228 µg/ml, respectively, in the first experiment and, 230 and 124 µg/mlin the second one. Although we have not identified any molecules acting as hatching factor (HF), here we present a list (44 candidate molecules) that can be explored in future studies to find an efficient HF.

7.
Molecules ; 25(7)2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32244463

RESUMO

Mexican spices are used in the supplementation of the human diet and as medicinal herbs for the particularly high amounts of compounds capable of deactivating free radicals. In addition, these spices can have beneficial effects on chronic, no-transmissible diseases such as type II diabetes and hypertension arterial. The objective of this study is to determine the content of phenolic compounds on the antioxidant activity and inhibitory enzymes of α-amylase, α-glucosidase and angiotensin-converting enzyme in melissa, peppermint, thyme and mint, which are subjected to microwave drying, conventional and freeze-drying to be used as alternative treatments. Spices were evaluated to determine total phenols, flavonoids, tannins, 2,2-Diphenyl-1-picrylhydrazyl (DPPH), (2,2'-azino-bis- (3-ethyl benzothiazolin-6-ammonium sulphonate) (ABTS) and Ferric Reducing/Antioxidant Power (FRAP), enzymatic activity. The investigation showed that conventional drying caused a decrease in antioxidant properties and inhibitory activity, in some species, while remained preserved in microwave drying and freeze-drying. The activity of polyphenol oxides and peroxidase decreases with high temperatures and these increase with the use of cold temperatures. This study aims to determine the extent of optimal drying required to preserve phenolic compounds, and the positive effect on antioxidant activity and enzymatic activity in in vitro models, which will produce benefits for the infusion processing industry and the pharmaceutical industry.


Assuntos
Fenóis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais , Antioxidantes/química , Antioxidantes/farmacologia , Liofilização , Medicina Tradicional , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/administração & dosagem , Especiarias , Relação Estrutura-Atividade
8.
Exp Parasitol ; 199: 17-23, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30790574

RESUMO

Exposing second-stage juveniles (J2) of Meloidogyne incognita in vitro to a phenolic compound sometimes fails to cause J2 mortality, but in tests in vivo the same compound may reduce the infectivity and population of the nematode. This work aimed to study the effect of phenolic compounds on M. incognita through in vitro and in vivo assays. In the in vitro assay 49 phenolic compounds were screened for their toxicity to M. incognita J2. As a result, D-(-)-4-hydroxyphenylglycine, t-butylhydroquinone, L-3-(3,4-dihydroxyphenyl)alanine, sesamol, 2,4-dihydroxyacetophenone, and p-anisaldehyde increased the J2 mortality. These compounds presented, respectively, the following lethal concentrations to 50% of J2 (LC50): 365, 352, 251, 218, 210, and 85 µg/mL, while Carbofuran (positive control) had 150 µg/mL. However, none of these compounds were efficient in controlling the nematode in inoculated tomato plants, even when 2.77-fold of their LC50 were used. Although inactive in the in vitro test at 500 µg/mL, hydroquinone (3.5 mg per plant) reduced M. incognita population and galls by up to 99% to levels similar to the nematicide Carbofuran (1.2 mg per plant). Additionally, hydroquinone increased the root weight when compared to the negative and positive controls, water/NaOH and Carbofuran, respectively. In this study, we showed that some phenolic compounds, hydroquinone in particular, revealed a potential new option for the control of M. incognita.


Assuntos
Fenóis/farmacologia , Solanum lycopersicum/parasitologia , Tylenchoidea/efeitos dos fármacos , Animais , Arbutina/administração & dosagem , Arbutina/química , Arbutina/farmacologia , Benzaldeídos/administração & dosagem , Benzaldeídos/química , Benzaldeídos/farmacologia , Ácidos Cafeicos/administração & dosagem , Ácidos Cafeicos/química , Ácidos Cafeicos/farmacologia , Carbofurano/administração & dosagem , Carbofurano/química , Carbofurano/farmacologia , Catecóis/administração & dosagem , Catecóis/química , Catecóis/farmacologia , Glicerol/administração & dosagem , Glicerol/química , Glicerol/farmacologia , Hidroquinonas/administração & dosagem , Hidroquinonas/química , Hidroquinonas/farmacologia , Hidroxibenzoatos/administração & dosagem , Hidroxibenzoatos/química , Hidroxibenzoatos/farmacologia , Dose Letal Mediana , Naftóis/administração & dosagem , Naftóis/química , Naftóis/farmacologia , Fenóis/administração & dosagem , Fenóis/química , Distribuição Aleatória , Resorcinóis/administração & dosagem , Resorcinóis/química , Resorcinóis/farmacologia , Fatores de Tempo
9.
Plant Dis ; 102(11): 2170-2179, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30207900

RESUMO

Volatile organic compounds (VOC) produced by green residues for the management of plant-parasitic nematodes are poorly studied for oilseed plants and some Brassica spp. To investigate the activity of VOC in vitro and as biofumigants, dry and aqueous macerates of broccoli (Brassica oleracea var. italica) shoots and sunflower (Helianthus annuus) seed were used against the root-knot nematode Meloidogyne incognita. VOC produced by sunflower seed caused higher mortality of M. incognita second-stage juveniles (J2) than VOC produced by broccoli shoots but both plant species were equally effective in decreasing the infectivity and reproduction of this nematode. The number of galls and eggs produced by the nematode in tomato roots was reduced by 89 and 95%, respectively, on average, at the highest concentrations of broccoli and sunflower seed macerates tested as biofumigants. When nematodes were placed in water exposed to broccoli VOC, J2 immobility increased and the number of galls and eggs produced by the nematode in tomato roots decreased 80 and 96%, respectively. Water exposed to sunflower seed VOC had no effect on the viability of the nematode. Gas chromatography was used to identify five and six chemical groups in broccoli and in sunflower seed macerates, respectively, but only alcohols, sulfurated VOC, and terpenes were detected in the water exposed to these plant macerates. Sulfurated VOC from the water exposed to broccoli macerates were found to be involved in its activity against M. incognita. The purified VOC dimethyl disulfide (DMDS) and 3-pentanol were tested directly against J2 and showed a lethal concentration of 176 and 918 µg/ml (ppm), respectively, whereas dimethyl sulfide had no effect against M. incognita. Furthermore, DMDS and 3-pentanol retained in water killed J2 and reduced gall formation and the number of eggs of M. incognita on tomato roots. Both these plant species produced toxic VOC to M. incognita, whereas only VOC retained in water exposed to broccoli had activity against M. incognita.


Assuntos
Antinematódeos/farmacologia , Brassica/química , Helianthus/química , Doenças das Plantas/parasitologia , Solanum lycopersicum/parasitologia , Tylenchoidea/efeitos dos fármacos , Compostos Orgânicos Voláteis/farmacologia , Animais , Antinematódeos/química , Antinematódeos/isolamento & purificação , Feminino , Fumigação , Óvulo/efeitos dos fármacos , Brotos de Planta/química , Sementes/química , Tylenchoidea/fisiologia , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação
10.
BMC Pediatr ; 17(1): 149, 2017 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-28629337

RESUMO

BACKGROUND: Sound transmission is used in the diagnosis of hip dysplasia since the end of the 80's. Aim of this study is to quantify the validity and reliability of electroacoustic probe for the diagnosis of hip dysplasia in neonates. METHODS: Diagnostic study included neonates aged 4-28 days, whose parents signed an informed consent. The probe was used three times for comparative sound transmission and with extension/flexion; hip ultrasound was performed with Graf technique as gold standard. Kappa was determined for intraobserver and interobserver reliability; validity was calculated with sensitivity, specificity, and predictive values. RESULTS: 100 neonates were included. For the comparative sound transmission, 0.80 and 0.81 Kappa were obtained for the intraobserver and interobserver respectively; with extension/flexion, Kappa 0.98 and 0.95 were obtained for the intraobserver and interobserver respectively. With comparative sound transmission, 44.8%, 97.7%, 76.5% and 91.3% for sensitivity, specificity, positive and negative predictive values, respectively; with extension/flexion test, the sensitivity, specificity, positive and negative predictive values: 82.8%, 99.4%, 96.0%, and 97.1%, respectively. CONCLUSION: The electroacoustic probe is moderate valid and reliable for the diagnosis of developmental dysplasia of the hip. TRIAL REGISTRATION: Open Science framework https://osf.io/kpf5s/?view_only=0a9682c6w1c842ad8e1d9a66e8dcf038.


Assuntos
Eletrodiagnóstico/métodos , Luxação Congênita de Quadril/diagnóstico , Som , Eletrodiagnóstico/instrumentação , Feminino , Humanos , Recém-Nascido , Masculino , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia
11.
Nutr Neurosci ; 19(7): 301-9, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25650657

RESUMO

OBJECTIVES: Prenatal malnutrition (M) and lead intoxication (Pb) have adverse effects on neuronal development; one of the cellular mechanisms involved is a disruption of the pro- and anti-oxidant balance. In the developing brain, the vulnerability of neuronal membrane phospholipids is variable across the different brain areas. This study assesses the susceptibility of different brain regions to damage by quitar tissue oxidative stress and lead quitar concentrations to determine whether the combined effect of prenatal malnutrition (M) and lead (Pb) intoxication is worse than the effect of either of them individually. METHODS: M was induced with an isocaloric and hypoproteinic (6% casein) diet 4 weeks before pregnancy. Intoxication was produced with lead acetate in drinking water, from the first gestational day. Both the M and Pb models were continued until the day of birth. Four brain regions (hippocampus, cortex, striatum, and cerebellum) were dissected out to analyze the lipid peroxidation (LP) levels in four groups: normally nourished (C); normally nourished but intoxicated with lead (CPb); malnourished (M); and M intoxicated with lead (MPb). RESULTS: Dam body and brain weights were significantly reduced in the fourth gestational week in the MPb group. Their pups had significantly lower body weights than those in the C and CPb groups. The PbM group exhibited significant increases of lead concentration and LP in all areas evaluated. A potentiation effect of Pb and M on LP was found in the cerebellum. DISCUSSION: This study provides information on how environmental conditions (intoxication and malnutrition) during the intrauterine period could differentially affect the development of neuronal plasticity and, in consequence, alter adult brain functions such as learning and memory.


Assuntos
Córtex Cerebral/metabolismo , Retardo do Crescimento Fetal/metabolismo , Intoxicação por Chumbo/fisiopatologia , Peroxidação de Lipídeos , Fenômenos Fisiológicos da Nutrição Materna , Complicações na Gravidez/fisiopatologia , Deficiência de Proteína/fisiopatologia , Animais , Animais Recém-Nascidos , Cerebelo/metabolismo , Cerebelo/patologia , Córtex Cerebral/patologia , Feminino , Desenvolvimento Fetal , Retardo do Crescimento Fetal/etiologia , Retardo do Crescimento Fetal/patologia , Intoxicação por Chumbo/complicações , Intoxicação por Chumbo/metabolismo , Intoxicação por Chumbo/patologia , Masculino , Neurônios/metabolismo , Tamanho do Órgão , Compostos Organometálicos/administração & dosagem , Estresse Oxidativo , Gravidez , Complicações na Gravidez/metabolismo , Complicações na Gravidez/patologia , Deficiência de Proteína/complicações , Deficiência de Proteína/metabolismo , Deficiência de Proteína/patologia , Ratos Sprague-Dawley , Aumento de Peso
12.
An Acad Bras Cienc ; 86(2): 525-538, 2014 06.
Artigo em Inglês | MEDLINE | ID: mdl-24770454

RESUMO

To contribute to the development of products to control Meloidogyne exigua, the bacteria Bacillus cereus and B. subtilis were cultivated in liquid medium to produce metabolites active against this plant-parasitic nematode. Fractionation of the crude dichloromethane extracts obtained from the cultures afforded uracil, 9H-purine and dihydrouracil. All compounds were active against M. exigua, the latter being the most efficient. This substance presented a LC50 of 204 µg/mL against the nematode, while a LC50 of 260 µg/mL was observed for the commercial nematicide carbofuran. A search for protein-ligand complexes in which the ligands were structurally similar to dihydrouracil resulted in the selection of phosphoribosyltransferases, the sequences of which were used in an in silico search in the genome of M. incognita for a similar sequence of amino acids. The resulting sequence was modelled and dihydrouracil and 9H-purine were inserted in the active site of this putative phosphoribosyltransferase resulting in protein-ligand complexes that underwent molecular dynamics simulations. Calculation of the binding free-energies of these complexes revealed that the dissociation constant of dihydrouracil and 9H-purine to this protein is around 8.3 x 10-7 and 1.6 x 10-6 M, respectively. Consequently, these substances and the putative phosphoribosyltransferase are promising for the development of new products to control M. exigua.

13.
Exp Parasitol ; 135(4): 661-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24140596

RESUMO

Meloidogyne exigua is a parasitic nematode of plants that causes great losses to coffee farmers. In an effort to develop parasitic controls, 154 chalcones were synthesized and screened for activity against this nematode. The best results were obtained with (2E)-1-(4'-nitrophenyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (6) with a 50% lethal concentration (LC50) of 171 µg/ml against M. exigua second-stage juveniles, in comparison to the commercially-available nematicide carbofuran which had an LC50 of 260 µg/ml under the same conditions. When coffee plants were used, 6 reduced the nematode population to ~50% of that observed in control plants. To investigate the mechanism of action of 6, an in silico study was carried out, which indicated that 6 may act against M. exigua through inhibition of a putative caffeic acid 3-O-methyltransferase homodimer, the amino acid sequence of which was determined by examining the genome of Meloidogyne incognita.


Assuntos
Benzaldeídos/química , Chalconas/farmacologia , Coffea/parasitologia , Metiltransferases/antagonistas & inibidores , Tylenchoidea/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Chalconas/química , Chalconas/isolamento & purificação , Dose Letal Mediana , Ligantes , Medicago sativa/enzimologia , Metiltransferases/química , Dados de Sequência Molecular , Doenças das Plantas/parasitologia , Doenças das Plantas/prevenção & controle , Tylenchoidea/enzimologia
14.
Open Life Sci ; 18(1): 20220529, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36742451

RESUMO

In addition to the known metabolic alterations, obesity has consequences at the brain level, driving imbalance in neurotransmitters such as glutamate (Glu), glutamine (Gln), and gamma-aminobutyric acid (GABA). The consumption of fruits with antioxidant properties, such as the berrycactus Myrtillocactus geometrizans, could have beneficial effects in such an imbalance. The study objective was to evaluate frontal cortex neurotransmitter levels and weight changes in rats fed with a high-fat diet (HFD) and MG. To achieve that, five groups of Wistar rats received different diets for 24 weeks: standard diet (SDt), HFD, HFD + MG extract 150 mg (HMg150), HFD + MG extract 300 mg (HMg300), and HFD + MG extract 450 mg (HMg450); rats received MG extract for the last 4 weeks. Weight and food intake were recorded every week, and also neurotransmitter levels were quantified using high-performance liquid chromatography. Groups fed with HFDs had increased Glu and Gln levels, decreased GABA, and also gained more weight compared to the SDt group; MG extract of 450 mg decreased Glu levels. Concentrations of 300 and 450 mg of MG extract decreased weight compared to the HFD and HMg150 groups. This study reports that HFDs have an impact on neurotransmitter levels and weight, MG extract showed a reduction in Glu concentration and weight.

15.
J Agric Food Chem ; 70(22): 6624-6633, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35622462

RESUMO

(E)-Cinnamaldehyde is very active against Meloidogyne incognita but has low persistence in soil. To circumvent this problem, esters of cinnamic acid were evaluated as a substitute for (E)-cinnamaldehyde. The best results under assays with M. incognita second-stage juveniles (J2) were obtained for the methyl esters of (E)-p-fluoro- (13), (E)-p-chloro- (14), and (E)-p-bromocinnamic acid (15), which showed lethal concentrations to 50% (LC50) J2 of 168, 95, and 216 µg/mL, respectively. Under the same conditions, the LC50 values for the nematicides carbofuran and fluensulfone were 160 and 34 µg/mL, respectively. Substances 13-15 were also active against nematode eggs, which account for most of the M. incognita population in the field. According to an in silico study, substances 13-15 can act against the nematode through inhibition of histone deacetylase. Therefore, esters 13-15 and histone deacetylase are potentially useful for the rational design of new nematicides for the control of M. incognita.


Assuntos
Tylenchoidea , Animais , Antinematódeos/farmacologia , Cinamatos , Ésteres/farmacologia , Histona Desacetilases
16.
Pest Manag Sci ; 78(2): 722-732, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34689397

RESUMO

BACKGROUND: The combination of biocontrol agents is a desirable strategy to improve control efficacy against the root-knot nematode (RKN) Meloidogyne incognita under field conditions. However, strains compatibility is generally tested in vitro and incompatible combinations are normally not further examined in experiments in planta. Therefore, there is virtually no information on the performance of incompatible strains. In this study, we evaluated two Bacillus strains previously described as incompatible in vitro for effects on plant growth and suppression of M. incognita, pathogenic fungi and nematophagous fungi. RESULTS: Strains BMH and INV were shown to be closely related to Bacillus velezensis. These strains, when applied individually, reduced the number of galls and eggs of M. incognita by more than 90% in tomato roots. When BMH and INV were combined (BMH + INV), RKN suppression and tomato shoot weight were lower compared to single-strain applications. Additionally, metabolites in cell-free supernatants and volatile organic compounds (VOCs) from strains BMH and INV had strong effects against the plant pathogens M. incognita, Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsiii, but not against three species of nematophagous fungi. Although strain INV and the combination BMH + INV emitted fewer VOCs than strain BMH, they were still capable of killing second-stage juveniles of M. incognita. CONCLUSIONS: Bacillus strains BMH and INV inhibited M. incognita and fungal pathogens, and promoted tomato growth. However, strain INV emitted fewer VOCs and the combination BMH + INV did not enhance the activity of the biocontrol strains against the RKN or their capacity to promote plant growth. © 2021 Society of Chemical Industry.


Assuntos
Ascomicetos , Bacillus , Solanum lycopersicum , Tylenchoidea , Compostos Orgânicos Voláteis , Animais , Raízes de Plantas
17.
An Acad Bras Cienc ; 83(3): 1091-6, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21739082

RESUMO

In order to select phytotoxin producing rhizobacteria to control weed plants, twenty five bacterial strains previously isolated from the rhizospheres of various plants were grown in a liquid medium and, after cell removal by centrifugation, the liquid phases were freeze-dried and the products were extracted with ethyl acetate/methanol. The extracts were concentrated to dryness under vacuum and dissolved in water and sucrose solution to be submitted to in vitro assays of lettuce (Lactuca sativa L.) seed germination and wheat (Triticum aestivum L.) coleoptile growth. Although most samples affected coleoptile growth, only those from four strains reduced lettuce seed germination. Two strains of Bacillus cereus, one strain of B. pumilus and one of Stenotrophoonas altophilia were the most promising microorganisms for producing phytotoxin and, consequently, for the development of new weed control products.


Assuntos
Toxinas Bacterianas/farmacologia , Citotoxinas/farmacologia , Bacilos e Cocos Aeróbios Gram-Negativos/isolamento & purificação , Lactuca/efeitos dos fármacos , Rizosfera , Triticum/efeitos dos fármacos , Toxinas Bacterianas/biossíntese , Citotoxinas/biossíntese , Bacilos e Cocos Aeróbios Gram-Negativos/química , Bacilos e Cocos Aeróbios Gram-Negativos/metabolismo , Lactuca/crescimento & desenvolvimento , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento
18.
EFORT Open Rev ; 6(8): 669-675, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34532074

RESUMO

Complete access to the posterior medial compartment of the knee may represent a technical challenge during arthroscopy in patients with a tight tibiofemoral joint space.Medial collateral release reduces direct iatrogenic cartilage damage in the medial compartment of the knee through manipulation with instruments.We recommend performing medial collateral release in surgeries that access the posteromedial compartment (e.g. partial meniscectomy for ruptures of the posterior horn of medial meniscus or posterior root repairs) when the patient has a tight tibiofemoral joint space.There are two main techniques to perform medial collateral release: inside-out and outside-in. Regardless of the technique used, releasing medial ligament structures is a safe and effective method to be used in the diagnosis and treatment of injuries to the medial compartment. Cite this article: EFORT Open Rev 2021;6:669-675. DOI: 10.1302/2058-5241.6.200128.

19.
Microbiol Res ; 255: 126925, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34823077

RESUMO

The production of volatile organic compounds (VOCs) acting against plant-parasitic nematodes has been characterized in different fungi; however, the role of VOCs emitted by Pochonia chlamydosporia in its trophic interaction with Meloidogyne incognita is still unknown. The aim of this study was to determine the effects of VOCs emitted by P. chlamydosporia strain Pc-10 on different stages (eggs, juveniles and female) of the M. incognita life cycle. Exposure of M. incognita eggs to VOCs released by Pc-10 resulted in a reduction up to 88 % in the nematode egg hatching, when compared to the control treatments. The VOCs emitted by Pc-10 also attracted M. incognita second-stage juveniles (J2). Through gas chromatography-mass spectrometry (GC-MS), three molecules were identified from the volatiles of the strain Pc-10, with 1,4-dimethoxybenzene being the major compound. In tests performed in vitro, 1,4-dimethoxybenzene at a concentration of 1050 µg mL-1 inhibited M. incognita egg hatching by up to 78.7 % compared to the control (0 µg mL-1) and attracted M. incognita J2 in all concentrations evaluated (1, 10, 100, 1000, and 10000 µg mL-1). The 1,4-dimethoxybenzene also showed fumigant and non-fumigant nematicidal activity against M. incognita. This compound presented lethal concentration for 50 % (LC50) of M. incognita J2 ranged from 132 to 136 µg mL-1. Fumigation with 1,4-dimethoxybenzene (100 mg) reduced egg hatching by up to 89 % and killed up to 86 % of M. incognita J2 compared to the control (0 µg mL-1). In vivo, the VOCs produced by Pc-10, 1,4-dimethoxybenzene, and the combination of both (Pc-10 + 1,4-dimethoxybenzene) attracted the M. incognita J2, compared to the respective controls. To the best of our knowledge, this is the first report on the attraction of M. incognita J2 and the toxicity to eggs and J2 by VOCs from P. chlamydosporia in which 1,4-dimethoxybenzene is the main toxin and attractant.

20.
Int J Surg Case Rep ; 77: 538-542, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33395841

RESUMO

INTRODUCTION: Lipomas are a rare cause of compressive neuropathy and they lead to atypical clinical presentation that can mimic carpal tunnel syndrome. CASE PRESENTATION: The authors describe a rare presentation of a carpal tunnel syndrome recurrence after a hand giant lipoma, presenting with rapidly compression neuropathy of the median nerve, 6 months after de primary surgery. DISCUSSION: Lipomas are common benign soft tumours. Their occurrence in the hand remains rare and they rarely cause secondary entrapment neuropathies. Carpal tunnel syndrome is mostly idiopathic and bilateral. Local factors should be suspected when these neuropathies present with atypical symptomatology or even when they recur after primary conventional surgical release. Investigation should consider images studies as this correct preoperative assessment leads to successful diagnosis and treatment.

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