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1.
PLoS Negl Trop Dis ; 14(7): e0008332, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32609727

RESUMO

Treatment and control of schistosomiasis still rely on only one effective drug, praziquantel (PZQ) and, due to mass treatment, the increasing risk of selecting for schistosome strains that are resistant to PZQ has alerted investigators to the urgent need to develop novel therapeutic strategies. The histone-modifying enzymes (HMEs) represent promising targets for the development of epigenetic drugs against Schistosoma mansoni. In the present study, we targeted the S. mansoni lysine-specific demethylase 1 (SmLSD1), a transcriptional corepressor, using a novel and selective synthetic inhibitor, MC3935, which was used to treat schistosomula and adult worms in vitro. By using cell viability assays and optical and electron microscopy, we showed that treatment with MC3935 affected parasite motility, egg-laying, tegument, and cellular organelle structures, culminating in the death of schistosomula and adult worms. In silico molecular modeling and docking analysis suggested that MC3935 binds to the catalytic pocket of SmLSD1. Western blot analysis revealed that MC3935 inhibited SmLSD1 demethylation activity of H3K4me1/2. Knockdown of SmLSD1 by RNAi recapitulated MC3935 phenotypes in adult worms. RNA-Seq analysis of MC3935-treated parasites revealed significant differences in gene expression related to critical biological processes. Collectively, our findings show that SmLSD1 is a promising drug target for the treatment of schistosomiasis and strongly support the further development and in vivo testing of selective schistosome LSD1 inhibitors.


Assuntos
Inibidores Enzimáticos/farmacologia , Histona Desmetilases/antagonistas & inibidores , Schistosoma mansoni/efeitos dos fármacos , Schistosoma mansoni/ultraestrutura , Esquistossomose mansoni/tratamento farmacológico , Animais , Anti-Helmínticos/farmacologia , Resistência a Medicamentos , Microscopia Eletrônica de Varredura , Oviposição/efeitos dos fármacos , Praziquantel/farmacologia , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/patologia
2.
Chemosphere ; 255: 126778, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32388266

RESUMO

The predatory bug Orius sauteri (Poppius) is currently one of the most important beneficial arthropods in Northeast Asia and used as a biological control agent of several small pest arthropods including Frankliniella occidentalis (Pergande). Two neonicotinoid chemical insecticides, acetamiprid and imidacloprid, mainly used in China as chemical control on F. occidentalis, although applied at sublethal concentrations in the field or greenhouse to protect beneficial arthropods, still may affect the predator O. sauteri. The objective of present work is to assess the long-term effects of 24-h exposure time to these two insecticides on the life-cycle of O. sauteri at application rates similar to the laboratory 24-h LC10, LC20 and LC30 of O. sauteri. Results showed that acetamiprid and imidacloprid at all tested concentrations significantly decreased the fecundity of O. sauteri females, while the effect of acetamiprid was higher than that of imidacloprid. Moreover, the oviposition period and longevity of O. sauteri to both insecticides shortened. The sublethal effects on the first progeny (F1 generation) were also found to increase nymphal mortality, shorten adult longevity and reduce fecundity. However, all treatments of acetamiprid and imidacloprid at the concentration of LC10, LC20 and LC30 caused no significant effect on the developmental time of different nymphal stages and sex ratio of the F1 generation. This paper is the first one that assesses the compatibility between neonicotinoid insecticides and O. sauteri, and shows that the application of acetamiprid and imidacloprid likely interferes with the population dynamic of O. sauteri.


Assuntos
Hemípteros/fisiologia , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Animais , China , Feminino , Fertilidade/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Ninfa/efeitos dos fármacos , Oviposição/efeitos dos fármacos
3.
PLoS One ; 15(5): e0233169, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407420

RESUMO

In broiler hens, the genetic selection increased susceptibility to metabolic disorders and reproductive dysfunctions. In human ovarian cells, grape seed extracts (GSE) improved steroid production. Here, we investigated the effects of a GSE dietary supplementation on egg production and quality, fertility parameters, Reactive Oxygen Species (ROS) and steroid content in yolk egg associated to plasma adipokines in broiler hens. For this, we designed two in vivo experiments, the first one included three groups of hens: A (control), B and C (supplemented with GSE at 0.5% and 1% of the total diet composition, respectively, since week 4), and the second one used two groups of hens: A (control) and D (supplemented with GSE at 1% of the total diet composition since hatching). We assessed the egg production from 23th to 40th weeks and quality at 33th week. After artificial inseminations, the fertility parameters were calculated. In egg yolk, Reactive Oxygen Species (ROS) level and steroid production were evaluated by Ros-Glo H202 and ELISA assay, respectively. Expression of steroidogenic enzymes and adipokines and their receptors was determined by RT-qPCR in ovarian cells and plasma adipokines (RARRES2, ADIPOQ and NAMPT) were evaluated by specific ELISA assays. The fertility parameters and egg production were unaffected by GSE supplementation whatever the experiment (exp.). However, the rate of double-yolk eggs decreased for all GSE supplemented groups (exp. 1 P <0.01, exp.2, P<0.02). In exp.1, C group eggs were bigger and larger (P<0.0001) and the shell elasticity was higher for both B and C (P<0.0003) as compared to control. In the egg yolk, GSE supplementation in both exp. reduced ROS content and steroidogenesis consistent with a decrease in P450 aromatase and StAR mRNA expression and basal in vitro progesterone secretion in granulosa cells (P<0.001). Interestingly, in both exp. RARRES2 plasma levels were positively correlated while ADIPOQ and NAMPT plasma levels were negatively correlated, with steroids and ROS in yolk (P<0.0001). Taken together, maternal dietary GSE supplementation did not affect egg production and fertility parameters whereas it reduced ROS content and steroidogenesis in yolk egg. Furthermore, it ameliorated egg quality by decreasing the number of double-yolk eggs and by improving the size of normal eggs and the elasticity of the shell. Taken together, our data suggest the possibility of using dietary maternal GSE to improve egg quality.


Assuntos
Galinhas/fisiologia , Suplementos Nutricionais , Fertilidade/efeitos dos fármacos , Extrato de Sementes de Uva/farmacologia , Ovário/metabolismo , Óvulo/metabolismo , Reprodução/efeitos dos fármacos , Esteroides/biossíntese , Adipocinas/sangue , Animais , Galinhas/sangue , Galinhas/genética , Dieta , Gema de Ovo/efeitos dos fármacos , Gema de Ovo/metabolismo , Feminino , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Ovário/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Óvulo/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Adipocina/genética , Receptores de Adipocina/metabolismo , Células Tecais/efeitos dos fármacos , Células Tecais/metabolismo
4.
PLoS One ; 15(5): e0232812, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407334

RESUMO

Sulfoxaflor, the first commercially available sulfoximine insecticide, has been used for the control of sap-feeding insect pests such as plant bugs and aphids on a variety of crops. However, its sublethal effects on the mirid bug Apolygus lucorum, one of the key insect pests of Bt cotton and fruit trees in China, have not been fully examined. Here, we evaluated the demography and feeding behaviour of A. lucorum exposed to sulfoxaflor. The leaf-dipping bioassay showed that the LC10 and LC30 of sulfoxaflor against 3rd-instar nymphs of this insect were 1.23 and 8.37 mg L-1, respectively. The LC10 significantly extended the nymphal duration and decreased the oviposition period by 5.29 days and female fecundity by 56.99% in the parent generation (F0). The longer duration of egg, 5th-instar nymphs, preadult, and male adult longevity were observed in the F1 generation (F1) at LC10. At the LC30, the duration of egg and 1st-instar nymph, female adult longevity, and oviposition period of the F1 were significantly shorter, while the nymphal duration in the F0 and duration of 5th-instar nymphs, preadult survival rate, and male adult longevity in the F1 significantly increased. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) in the F1 were not significantly affected by these two concentrations, whereas the mean generation time (T) was lower at the LC30. Additionally, the probe counts and cells mixture feeding time were markedly lengthened by the LC10 and LC30, respectively, when A. lucorum nymphs exposed to sulfoxaflor fed on Bt cotton plants without insecticides. These results clearly indicate that sulfoxaflor causes sublethal effects on A. lucorum and the transgenerational effects depend on the tested concentrations.


Assuntos
Heterópteros/patogenicidade , Inseticidas/farmacologia , Controle de Pragas , Piridinas/farmacologia , Compostos de Enxofre/farmacologia , Animais , Fertilidade/efeitos dos fármacos , Frutas/parasitologia , Gossypium/parasitologia , Heterópteros/efeitos dos fármacos , Humanos , Longevidade/efeitos dos fármacos , Ninfa/efeitos dos fármacos , Ninfa/patogenicidade , Oviposição/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Árvores/parasitologia
5.
Anim Sci J ; 91(1): e13387, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468650

RESUMO

This study was conducted to determine the effects of diet supplementation of laying hens with antimicrobial peptides (AMP) on egg production, egg quality and caecal microbiota. A total of 360 Hy-Line Brown laying hens (72 weeks old) were divided into three groups with four replicates of 30 birds each. The laying hens were fed with the basal diet (Control), the basal diet + 50 mg/kg AMP (group 1) and the basal diet + 100 mg/kg AMP (group 2). The experiment lasted for 45 d. Eggs were collected daily and caecal samples were collected at the end of the experiment. The results showed that AMP supplementation caused a significantly increased laying rate and decreased feed/egg ratio (p ï¼œ .05). Meanwhile, a distinctive difference in cecal microbiota was observed between AMP and control groups and the average values of microbial diversity and richness were lower in the AMP group than in the control group. At the phylum level, the relative abundance of Verrucomicrobia and Cyanobacteria were lower in the AMP group than in the control group. In conclusion, the results indicated that dietary supplementation with AMP can improve egg production and affect the cecal microbial community membership and structure of hens during late laying period.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/farmacologia , Ceco/microbiologia , Galinhas/microbiologia , Galinhas/fisiologia , Dieta/veterinária , Ovos , Qualidade dos Alimentos , Oviposição/efeitos dos fármacos , Animais , Suplementos Nutricionais , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos
6.
Parasitol Res ; 119(7): 2159-2176, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32424554

RESUMO

The proteasome is the key player in the cellular protein degradation machinery and is pivotal for protein homeostasis and Schistosoma mansoni (S. mansoni) survival. Our group study provides insights into proteasome inhibitors and reveals that selective schistosomiasis agents represent an interesting branch of proteasome research linked to the development of new drugs for this neglected disease. Here, we explored the phenotypic response of S. mansoni to b-AP15, a bis-benzylidine piperidone that inhibits 26S proteasome deubiquitinases (DUBs), ubiquitin-specific protease 14 (USP14), and ubiquitin carboxyl-terminal hydrolase 5 (UCHL5). b-AP15 induces a modest decrease in egg production in vitro and reduces viability, leading to the death of parasite couples. This inhibitor also induces a twofold increase in the accumulation of polyubiquitinated proteins in S. mansoni adult worms and causes tegument changes such as disintegration, wrinkling, and bubble formation, both throughout the length of the parasite and in the oral sucker. b-AP15 alters the cell organelles of adult S. mansoni worms, and we specifically observed mitochondrial alterations, which are suggestive of proteotoxic stress leading to autophagy. Taken together, these results indicate that the deubiquitinase function of the proteasome is essential for the parasite and support the hypothesis that the proteasome constitutes an interesting drug target for the treatment of schistosomiasis.


Assuntos
Enzimas Desubiquitinantes/antagonistas & inibidores , Oviposição/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Animais , Feminino , Proteínas de Helminto/metabolismo , Piperidonas/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Schistosoma mansoni/metabolismo , Schistosoma mansoni/fisiologia , Ubiquitinação/efeitos dos fármacos
7.
Bull Environ Contam Toxicol ; 104(5): 588-594, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32193571

RESUMO

Female vinegar flies (Drosophila melanogaster) preferentially oviposit eggs on oviposition substrates that decrease larval foraging costs. We tested whether female D. melanogaster would avoid oviposition substrates containing lead (Pb2+), which could potentially decrease offspring fitness. Wild type D. melanogaster were reared on control or Pb-treated medium from egg stage to adulthood and tested for differences in oviposition substrate preference, fecundity (number of eggs laid) and Pb accumulation. Control females laid a significantly lower proportion of eggs on Pb-treated substrates than Pb-treated females. Pb-treated females laid significantly more eggs than control females. Pb-treated adults accumulated significantly more Pb than control-treated adults. These results indicate that Pb exposure disrupts normal oviposition avoidance behaviors, which could increase larval foraging costs for larval offspring. These factors could induce population declines and have cascading implications for the ecosystem.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Larva/efeitos dos fármacos , Chumbo/toxicidade , Oviposição/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Drosophila melanogaster/anatomia & histologia , Drosophila melanogaster/fisiologia , Ecossistema , Feminino , Fertilidade/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Modelos Teóricos
8.
Arch Insect Biochem Physiol ; 104(3): e21669, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32190926

RESUMO

Drosophila suzukii Matsumura (Diptera: Drosophilidae) is an invasive, destructive crop pest that originated in South East Asia. D. suzukii recently invaded Western countries and is threatening both European and American fruit industries. It is extremely attracted to otherwise undamaged, ripening fruits, unlike most other Drosophila species that attack only decaying or rotten fruits. Recent studies on different insect species showed that several naturally occurring compounds of easy market availability showing deterrent action may be used to supplement mass catches with food traps. Based on these considerations, the aim of the present work was to test the effects of some natural compounds (alone or in the mixture) on the olfactory system of the D. suzukii and the behavioral responses evoked. We measured by electroantennogram (EAG) recordings, the olfactory sensitivity of antennae to increasing concentrations of eugenol, vanillin, menthol, cis-jasmone; eugenol + vanillin, +menthol, +cis-jasmone; vanillin + menthol, +cis-jasmone. In addition, the behavioral responses to the same compounds and mixtures were evaluated. Our electrophysiological results show a dose-response relationship between the EAG amplitudes and the increasing concentrations of the olfactory compound. The behavioral results show that the number of laid eggs is significantly different between the standard diet and the standard diet + natural compound. These results underline a specificity in the olfactory sensitivity and in the ovipositing behavior of D. suzukii females; also, they could be valuable for the identification of key chemicals aimed at the future development of strategies in the management and control of this harmful insect for crops.


Assuntos
Drosophila/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Olfato , Animais , Antenas de Artrópodes/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Benzaldeídos , Ciclopentanos , Relação Dose-Resposta a Droga , Drosophila/fisiologia , Fenômenos Eletrofisiológicos , Eugenol , Comportamento Alimentar , Feminino , Repelentes de Insetos , Mentol , Odorantes , Oxilipinas
9.
Artigo em Inglês | MEDLINE | ID: mdl-32193759

RESUMO

The chive maggot, Bradysia odoriphaga (Yang and Zhang) is an economically important insect pest, affecting many key vegetables, including Chinese chive, especially in northern China. Chlorfenapyr, a halogenated pyrrole insecticide that interferes with mitochondrial oxidative phosphorylation is widely used against B. odoriphaga. In this study, we evaluated selection-induced resistance to chlorfenapyr and fitness costs in B. odoriphaga. The results showed that B. odoriphaga developed 43.32-fold resistance after continuous exposure to chlorfenapyr for over 10 consecutive generations. The life-history traits of chlorfenapyr-resistant and susceptible strains were compared using age-stage, two-sex life table approach. No significant effects were observed on the longevity and pre-adult period. However, reduction in the total pre-oviposition period (TPOP) and fecundity (eggs/female) were observed in the resistant strain. Moreover, the demographic parameters such as intrinsic rate of increase (r), net reproductive rate (R0) and finite rate of increase (λ) were also decreased significantly in the resistant strain compared to the susceptible strain. These results showed the potential of B. odoriphaga to develop resistance against chlorfenapyr under continuous selection pressure. Furthermore, there was a fitness cost linked with chlorfenapyr resistance in B. odoriphaga. We conclude that a better knowlegde on the trade-off at play between resistance degree and fitness cost could be crucial for developing further management of B. odoriphaga in China.


Assuntos
Dípteros/fisiologia , Inseticidas/toxicidade , Piretrinas/toxicidade , Animais , Feminino , Fertilidade/efeitos dos fármacos , Resistência a Inseticidas , Masculino , Oviposição/efeitos dos fármacos , Reprodução/efeitos dos fármacos
10.
Arch Insect Biochem Physiol ; 104(2): e21665, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32091155

RESUMO

Insect pests can cause crop damage in yield or quality, resulting in profit losses for farmers. The primary approach to control them is still the use of chemical pesticides resulting in significant hazards to the environment and human health. Biological control and the sterile insect technique are alternative strategies to improve agriculture protection. However, both strategies have significant limitations. A newly introduced approach that could be both effective and species-specific is the RNA interference mechanism. One key point for the success of this strategy is the delivery method of double-strand RNA (dsRNA) to the insects. A method of dsRNA delivery to insects with potential use in the field is the oral delivery, feeding the insects engineered microorganisms that produce dsRNA. Here, we present the first protocol for dsRNA feeding using modified bacteria, in the olive fruit fly, the most important insect pest of cultivated olives. We chose to target the sex peptide receptor gene. The sex peptide receptor interacts with the sex peptide, a peptide that is responsible for the postmating behavior in the model organism, Drosophila melanogaster. Feeding the female olive fruit fly with bacteria that produced dsRNA for the sex peptide receptor gene resulted in the development of female insects with significantly lower oviposition rates. Administration of dsRNA producing bacteria in insect diet against target genes that lead to genetic sexing or female-specific lethality could be added in the armory of control methods.


Assuntos
Proteínas de Insetos/genética , Oviposição/efeitos dos fármacos , RNA de Cadeia Dupla/farmacologia , Receptores de Peptídeos/genética , Tephritidae/fisiologia , Animais , Proteínas de Insetos/metabolismo , Receptores de Peptídeos/metabolismo , Tephritidae/genética
11.
J Insect Sci ; 20(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31927595

RESUMO

Bactrocera dorsalis (Hendel) is a notorious insect pest that attacks diverse vegetables and fruits worldwide. The sterile insect technique has been developed as an environmentally friendly and effective control method that depends on the mass production of target flies. Because dietary yeast (protein) and sucrose (carbohydrate) are important in adult diets, yeast:sucrose (Y:S) mixtures are crucial for the mass-rearing of B. dorsalis. In this study, we found adult diets with different ratios of yeast to sucrose-influenced fecundity, and an extremely high or low Y:S ratios significantly decreased egg production of B. dorsalis. Additionally, the maximum oviposition efficiency was realized at dietary yeast to sucrose ratios of 1:1 and 1:3, suggesting their potential use to produce more eggs for the mass production of B. dorsalis. Here, new gel diets having different yeast concentrations (g/L water) were also assessed for rearing B. dorsalis larvae. Gel diets containing 20 g/L yeast led to a higher pupation, pupal weight and adult eclosion rate, and a shorter developmental time than other yeast concentrations. Moreover, the present gel diet also resulted in greater pupal production and adult emergence rates than previously used liquid and solid artificial diets, revealing that it is suitable for rearing B. dorsalis larvae. This research provides a useful reference on artificial diets mixtures for mass rearing B. dorsalis, which is critical for employing the sterile insect technique.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Oviposição , Tephritidae/fisiologia , Animais , Dieta , Feminino , Fertilidade/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Oviposição/efeitos dos fármacos , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Pupa/fisiologia , Sacarose/administração & dosagem , Tephritidae/efeitos dos fármacos , Tephritidae/crescimento & desenvolvimento , Fermento Seco/administração & dosagem
12.
Exp Parasitol ; 208: 107793, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31711973

RESUMO

Praziquantel (PZQ) is the sole drug used to treat schistosomiasis, and the probability of developing resistance is growing the longer it is relied upon, justifying the search for alternatives. Phosphodiesterases (PDEs), particularly the PDE4 family, have attracted considerable attention as drug targets, including in Schistosoma mansoni, and especially SmPDE4A. This study investigates the potential antischistosomal activity of human PDE4 and potent SmPDE4A inhibitor roflumilast, either alone or combined with PZQ. In vitro, roflumilast resulted in a significant, concentration-dependent reduction in egg production but not of worm viability. In vitro exposure to roflumilast in combination with a low concentration of PZQ was less effective than PZQ alone, pointing to antagonism. S. mansoni-infected mice treated with roflumilast showed significant reductions in worm burden (27%) as well as hepatic and intestinal egg burdens (~28%) two weeks post treatment. Scanning EM of worms isolated from roflumilast-treated and untreated mice did not reveal noticeable changes to their tegument. S. mansoni-infected mice treated with a fixed dosage of roflumilast and a variable dosage of PZQ resulted in a higher reduction in worm burden, reduced hepatic egg counts, absence of immature eggs and a marked increase in dead eggs, compared to PZQ alone. However, the combination resulted in increased animal mortality, probably attributable to pharmacodynamic interactions between the two drugs. Although this study marks the first report of in vivo antischistosomal potential by a PDE inhibitor, an important proof of concept, we conclude that the antischistosomal effects of roflumilast are insufficient to warrant further development.


Assuntos
Aminopiridinas/farmacologia , Anti-Helmínticos/farmacologia , Benzamidas/farmacologia , Inibidores da Fosfodiesterase 4/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Animais , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/antagonistas & inibidores , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/efeitos dos fármacos , Ciclopropanos/farmacologia , Relação Dose-Resposta a Droga , Feminino , Concentração Inibidora 50 , Masculino , Camundongos , Microscopia Eletrônica de Varredura , Oviposição/efeitos dos fármacos , Praziquantel/farmacologia , Schistosoma mansoni/enzimologia , Schistosoma mansoni/fisiologia , Schistosoma mansoni/ultraestrutura
13.
Parasitol Int ; 74: 101917, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31004804

RESUMO

In the present study, the larvicidal activity of ageing aqueous suspensions of spinosad against larvae of Culex pipiens biotype molestus, as well as their effect on the oviposition preferences of adult gravid females were evaluated in laboratory bioassays. Spinosad was applied at its label dose and the aqueous stock suspensions were stored for various ageing intervals up to 38 days. Untreated distilled water and diflubenzuron served as negative and positive control, respectively. Stock suspensions were taken after 0, 2, 6, 8, 16, 30 and 38 days of storage for diflubenzuron and after 0, 2, 6, 8, 20 and 27 days for spinosad, and were used for the bioassays. Furthermore, the effect of spinosad on the oviposition response of Cx. p. biotype molestus gravid females was investigated in two-choice oviposition preference bioassays. Spinosad was evaluated at half of its label dose and at its label dose, whereas diflubenzuron and distilled water served as positive and negative control, respectively. Results showed that both insecticides were found highly effective for the control of Cx. p. biotype molestus larvae, for ageing intervals up to 27 and 38 days for spinosad and diflubenzuron, respectively. Spinosad acted immediately after the preparation of the insecticidal solution (LT50 = 1.5 h), whereas for aged samples, LT50 values increased with the increase of the ageing interval (LT50 = 5 days for the 27 days old sample). For diflubenzuron, ageing time increased its insecticidal activity, as for aged diflubenzuron-treated solutions, lower LT50 values were achieved. In the oviposition preference bioassays, significantly fewer egg rafts were laid in water treated with spinosad at its label dose compared to control. However, this was not the case for water treated with spinosad at half of its label dose. Oviposition Activity Index (OAI) values were always comprised between -0.3 and 0.3, showing no relevant oviposition deterrence or attraction. The results of the present study contribute to our understanding of the effect of ageing on insecticidal solutions widely used in urban areas to control Cx. p. biotype molestus. Although an important vector of high public health importance, Cx. p. biotype molestus has been scarcely studied as target of environmentally and toxicologically reduced risk insecticides, such as spinosad.


Assuntos
Quitina/antagonistas & inibidores , Culex , Inseticidas/farmacologia , Macrolídeos/farmacologia , Oviposição/efeitos dos fármacos , Animais , Bioensaio , Quitina/biossíntese , Combinação de Medicamentos , Feminino , Larva , Mosquitos Vetores
14.
Theriogenology ; 142: 120-130, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31593879

RESUMO

Daidzein (DA) is a kind of isoflavone that is extracted primarily from soy plants and that has become increasingly popular as a dietary supplement. The objective of this study was to evaluate the effects of dietary DA supplementation for laying breeder hens on laying performance, reproductive organ development, hatching performance of seed eggs, and growth performance of offspring and to investigate the underlying molecular mechanisms. A total of 180 55-week-old laying breeder hens were randomly divided into 2 treatment groups and, after 3 weeks of acclimation, were fed either a control diet (CON) or a DA-supplemented diet (DAS, CON+30 mg/kg DA) for a total of 12 weeks. DAS treatment improved the laying rate, luteinizing hormone (LH) levels, and small yellow follicle (SYF) numbers without negative effects on the hatchability of breeder eggs or the growth performance of offspring. High-throughput RNA sequencing was utilized to identify differentially expressed genes in the SYF granulosa layer in the two groups. Transcriptome analysis showed that 161 genes (fold change ≥2 or ≤0.5; P-value<0.05) were significantly differentially expressed between the two groups, including 139 upregulated genes and 22 downregulated genes. Gene ontology (GO) functional annotation analysis revealed potential genes, processes and pathways involved in cell proliferation and differentiation related to the improvement of laying performance stimulated by DA. Dietary DA supplementation for laying breeder hens improved laying performance and reproductive performance with no negative impacts on hatchability or offspring growth. A series of differentially expressed genes in SYF granulosa cells were significantly upregulated in the DAS group relative to the CON group. This study provides insight into the genetic architecture of the transcriptome of the SYF granulosa layer in layer breeding hens and proposes candidate genes that respond to dietary DA.


Assuntos
Galinhas/genética , Galinhas/fisiologia , Isoflavonas/farmacologia , Oviposição/genética , Transcriptoma , Ração Animal/análise , Animais , Peso Corporal , Dieta/veterinária , Suplementos Nutricionais , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Masculino , Oviposição/efeitos dos fármacos
15.
J Chem Ecol ; 45(11-12): 982-992, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31784860

RESUMO

Plants have evolved intricate defence strategies against herbivore attack which can include activation of defence in response to stress-related volatile organic compounds (VOCs) emitted by neighbouring plants. VOCs released by intact molasses grass (Melinis minutiflora), have been shown to repel stemborer, Chilo partellus (Swinhoe), from maize and enhance parasitism by Cotesia sesamiae (Cameron). In this study, we tested whether the molasses grass VOCs have a role in plant-plant communication by exposing different maize cultivars to molasses grass for a 3-week induction period and then observing insect responses to the exposed plants. In bioassays, C. partellus preferred non-exposed maize landrace plants for egg deposition to those exposed to molasses grass. Conversely, C. sesamiae parasitoid wasps preferred volatiles from molasses grass exposed maize landraces compared to volatiles from unexposed control plants. Interestingly, the molasses grass induced defence responses were not observed on hybrid maize varieties tested, suggesting that the effect was not simply due to absorption and re-emission of VOCs. Chemical and electrophysiological analyses revealed strong induction of bioactive compounds such as (R)-linalool, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene from maize landraces exposed to molasses grass volatiles. Our results suggest that constitutively emitted molasses grass VOCs can induce direct and indirect defence responses in neighbouring maize landraces. Plants activating defences by VOC exposure alone could realize enhanced levels of resistance and fitness compared to those that launch defence responses upon herbivore attack. Opportunities for exploiting plant-plant signalling to develop ecologically sustainable crop protection strategies against devastating insect pests such as stemborer C. partellus are discussed.


Assuntos
Compostos Orgânicos Voláteis/química , Zea mays/metabolismo , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/metabolismo , Animais , Produtos Agrícolas , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Herbivoria , Interações Hospedeiro-Parasita , Melaço , Mariposas/parasitologia , Oviposição/efeitos dos fármacos , Compostos Orgânicos Voláteis/metabolismo , Vespas/fisiologia , Zea mays/parasitologia
16.
PLoS One ; 14(11): e0225425, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31765429

RESUMO

Schistosomiasis is caused by a trematode of the genus Schistosoma and affects over 200 million people worldwide. The only drug recommended by the World Health Organization for treatment and control of schistosomiasis is praziquantel. Development of new drugs is therefore of great importance. Thiazoles are regarded as privileged structures with a broad spectrum of activities and are potential sources of new drug prototypes, since they can act through interactions with DNA and inhibition of DNA synthesis. In this context, we report the synthesis of a series of thiazole derivatives and their in vitro schistosomicidal activity by testing eight molecules (NJ03-08; NJ11-12) containing thiazole structures. Parameters such as motility and mortality, egg laying, pairing and parasite viability by ATP quantification, which were influenced by these compounds, were evaluated during the assays. Scanning electron microscopy (SEM) was utilized for evaluation of morphological changes in the tegument. Schistosomula and adult worms were treated in vitro with different concentrations (6.25 to 50 µM) of the thiazoles for up to 5 and 3 days, respectively. After in vitro treatment for five days with 6.25 µM NJ05 or NJ07 separately, we observed a decrease of 30% in schistosomula viability, whilst treatment with NJ05+NJ07 lead to a reduction of 75% in viability measured by ATP quantitation and propidium iodide labeling. Adult worms' treatment with 50 µM NJ05, NJ07 or NJ05 + NJ07 showed decreased motility to 30-50% compared with controls. Compound NJ05 was more effective than NJ07, and adult worm viability after three days was reduced to 25% in parasites treated with 50 µM NJ05, compared with a viability reduction to 40% with 50 µM NJ07. SEM analysis showed severe alterations in adult worms with formation of bulges and blisters throughout the dorsal region of parasites treated with NJ05 or NJ07. Oviposition was extremely affected by treatment with the NJ series compounds; at concentrations of 25 µM and 50 µM, oviposition reached almost zero with NJ05, NJ07 or NJ05 + NJ07 already at day one. Tested genes involved in egg biosynthesis were all confirmed by qPCR as downregulated in females treated with 25 µM NJ05 for 2 days, with a significant reduction in expression of p14, Tyrosinase 2, p48 and fs800. NJ05, NJ07 or NJ05+NJ07 treatment of HEK293 (human embryonic cell line) and HES (human epithelial cell line) showed EC50 in the range of 18.42 to 145.20 µM. Overall, our results demonstrate that those molecules are suitable targets for further development into new drugs for schistosomiasis treatment, although progress is needed to lessen the cytotoxic effects on human cells. According to the present study, thiazole derivatives have schistosomicidal activities and may be part of a possible new arsenal of compounds against schistosomiasis.


Assuntos
Anti-Helmínticos/toxicidade , Schistosoma mansoni/efeitos dos fármacos , Tiazóis/toxicidade , Animais , Anti-Helmínticos/síntese química , Feminino , Células HEK293 , Humanos , Masculino , Oviposição/efeitos dos fármacos , Schistosoma mansoni/fisiologia , Tiazóis/síntese química
17.
J Chem Ecol ; 45(11-12): 926-933, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31758292

RESUMO

Chemical examination of plant constituents responsible for oviposition by a Magnoliaceae-feeding butterfly, Graphium doson, was conducted using its major host plant, Michelia compressa. A methanol extract prepared from young leaves of the plant elicited a strong oviposition response from females. The methanolic extract was then separated by solvent partition into three fractions: CHCl3, i-BuOH, and aqueous fractions. Active substance(s) resided in both i-BuOH- and water-soluble fractions. Bioassay-guided further fractionation of the water-soluble substances by means of various chromatographic techniques led to the isolation of an oviposition stimulant. The stimulant was identified as D-(+)-pinitol on the basis of 13C NMR spectra and physicochemical properties. D-(+)-Pinitol singly exhibited a moderate oviposition-stimulatory activity at a dose of 150 µg/cm2. This compound was present also in another host plant, Magnolia grandiflora, in a sufficient amount to induce oviposition behavior of G. doson females. Certain cyclitols including D-(+)-pinitol have been reported to be involved in stimulation of oviposition by some Aristolochiaceae- and Rutaceae-feeding papilionid butterflies. A possible pathway of phytochemical-mediated host shifts in the Papilionidae, in which certain cyclitols could enact important mediators, is discussed in relation to the evolution of cyclitol biosynthesis in plants.


Assuntos
Magnolia/química , Oviposição/efeitos dos fármacos , Extratos Vegetais/química , Animais , Butanóis/química , Borboletas , Ciclitóis/química , Ciclitóis/metabolismo , Feminino , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Inositol/análogos & derivados , Inositol/química , Inositol/metabolismo , Magnolia/metabolismo , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Solubilidade , Água/química
18.
J Chem Ecol ; 45(11-12): 946-958, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31755018

RESUMO

There are contrasting hypotheses regarding the role of plant volatiles in host plant location. We used the grape berry moth (GBM; Paralobesia viteana)-grape plant (Vitis spp.) complex as a model for studying the proximate mechanisms of long distance olfactory-mediated, host-plant location and selection by a specialist phytophagous insect. We used flight tunnel assays to observe GBM female in-flight responses to host (V. riparia) and non-host (apple, Malus domestica; and gray dogwood, Cornus racimosa,) odor sources in the form of plant shoots, extracts of shoots, and synthetic blends. Gas chromatography-electroantennographic detection and gas chromatography/mass spectrometry analyses were used to identify antennal-active volatile compounds. All antennal-active compounds found in grape shoots were also present in dogwood and apple shoots. Female GBM flew upwind to host and non-host extracts and synthetic blends at similar levels, suggesting discrimination is not occurring at long distance from the plant. Further, females did not land on sources releasing plant extracts and synthetic blends, suggesting not all landing cues were present. Additionally, mated and unmated moths displayed similar levels of upwind flight responses to all odor sources, supporting the idea that plant volatiles are not functioning solely as ovipositional cues. The results of this study support a hypothesis that GBM females are using volatile blends to locate a favorable habitat rather than a specific host plant, and that discrimination is occurring within the habitat, or even post-landing.


Assuntos
Mariposas/fisiologia , Oviposição/efeitos dos fármacos , Extratos Vegetais/química , Vitis/química , Compostos Orgânicos Voláteis/química , Animais , Comportamento Animal , Cornus/química , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Controle de Insetos/métodos , Malus/química , Odorantes/análise , Brotos de Planta/química , Olfato , Vitis/parasitologia , Compostos Orgânicos Voláteis/metabolismo
19.
PLoS Negl Trop Dis ; 13(11): e0007693, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31730617

RESUMO

BACKGROUND: Praziquantel represents the frontline chemotherapy used to treat schistosomiasis, a neglected tropical disease (NTD) caused by infection with macro-parasitic blood fluke schistosomes. While this drug is safe, its inability to kill all schistosome lifecycle stages within the human host often requires repeat treatments. This limitation, amongst others, has led to the search for novel anti-schistosome replacement or combinatorial chemotherapies. Here, we describe a repositioning strategy to assess the anthelmintic activity of epigenetic probes/inhibitors obtained from the Structural Genomics Consortium. METHODOLOGY/PRINCIPLE FINDINGS: Thirty-seven epigenetic probes/inhibitors targeting histone readers, writers and erasers were initially screened against Schistosoma mansoni schistosomula using the high-throughput Roboworm platform. At 10 µM, 14 of these 37 compounds (38%) negatively affected schistosomula motility and phenotype after 72 hours of continuous co-incubation. Subsequent dose-response titrations against schistosomula and adult worms revealed epigenetic probes targeting one reader (NVS-CECR2-1), one writer (LLY-507 and BAY-598) and one eraser (GSK-J4) to be particularly active. As LLY-507/BAY-598 (SMYD2 histone methyltransferase inhibitors) and GSK-J4 (a JMJD3 histone demethylase inhibitor) regulate an epigenetic process (protein methylation) known to be critical for schistosome development, further characterisation of these compounds/putative targets was performed. RNA interference (RNAi) of one putative LLY-507/BAY-598 S. mansoni target (Smp_000700) in adult worms replicated the compound-mediated motility and egg production defects. Furthermore, H3K36me2, a known product catalysed by SMYD2 activity, was also reduced by LLY-507 (25%), BAY-598 (23%) and siSmp_000700 (15%) treatment of adult worms. Oviposition and packaging of vitelline cells into in vitro laid eggs was also significantly affected by GSK-J4 (putative cell permeable prodrug inhibitor of Smp_034000), but not by the related structural analogue GSK-J1 (cell impermeable inhibitor). CONCLUSION/SIGNIFICANCE: Collectively, these results provide further support for the development of next-generation drugs targeting schistosome epigenetic pathway components. In particular, the progression of histone methylation/demethylation modulators presents a tractable strategy for anti-schistosomal control.


Assuntos
Reposicionamento de Medicamentos/métodos , Epigênese Genética , Chumbo/farmacologia , Schistosomatidae/efeitos dos fármacos , Schistosomatidae/genética , Esquistossomose/tratamento farmacológico , Animais , Anti-Helmínticos/farmacologia , Benzazepinas/farmacologia , Biologia Computacional/métodos , Relação Dose-Resposta a Droga , Feminino , Genômica , Células Hep G2 , Histonas/genética , Humanos , Histona Desmetilases com o Domínio Jumonji , Masculino , Modelos Moleculares , Simulação de Acoplamento Molecular , Oviposição/efeitos dos fármacos , Pirimidinas/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Schistosoma mansoni/genética , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/parasitologia
20.
J Insect Sci ; 19(5)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31616937

RESUMO

We evaluated the insecticide activities of aqueous extracts of five species of plants from the Ecuadorian Amazon (Deguelia utilis (ACSm.) AMGAZEVEDO (Leguminosae: Papilionoideae), Xanthosoma purpuratum K. Krause (Alismatales: Araceae), Clibadium sp. (Asteracea: Asterales), Witheringia solanacea L'Hér (Solanales: Solanaceae), and Dieffenbachia costata H. Karst. ex Schott (Alismatales: Araceae)) plus Cymbopogon citratus Stapf. (Poales: Poaceae) under laboratory, open-field conditions in Plutella xylostella L. (diamondback moth), and semifield conditions in Brevicoryne brassicae L. Tap water was used as a negative control, and synthetic insecticides were used as positive controls. In a laboratory bioassay, aqueous extracts of D. utilis resulted in P. xylostella larval mortality. In contrast to chlorpyrifos, all botanicals were oviposition deterrents. All extracts except Clibadium sp. decreased leaf consumption by P. xylostella larvae. In semifield experiments, D. utilis, Clibadium sp., D. costata, and X. purpuratum initially controlled the population of B. brassicae, but 7 d after application, all botanicals except the D. utilis lost their ability to control the pest. In field experiments on broccoli crops in both dry and rainy seasons, the extracts did not control the abundance of P. xylostella, where as a mixture of two insecticides (chlorpyrifos + lambda cyhalothrin) did. These results show some incongruences from laboratory to semifield and field conditions, indicating that more studies, including the identification of the chemicals responsible for the biological activity, its stability, and the effects of chemotypes on insecticidal activity, are needed to understand the potential of these plant species as botanical insecticides.


Assuntos
Afídeos , Controle de Insetos , Inseticidas , Mariposas , Extratos Vegetais , Animais , Afídeos/crescimento & desenvolvimento , Equador , Comportamento Alimentar/efeitos dos fármacos , Feminino , Larva/crescimento & desenvolvimento , Mariposas/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Oviposição/efeitos dos fármacos
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