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1.
J Insect Sci ; 21(2)2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33686433

RESUMO

Animals use olfaction to detect developmentally significant volatile organic compounds (VOCs) in their local environment. As part of a wider study aiming to demonstrate that the olfactory responses of animals to VOCs can be modified through the creation of a drug-addicted status and association with a selected VOC, we investigated nicotine and tobacco smoke particulate (TSP) extract as possible addictive compounds for male German cockroaches, Blattella germanica (Linnaeus). In feeding experiments using an artificial food stimulus, food treated with TSP extract was preferred over untreated food. Surprisingly, nicotine, which was expected to be the most important addictive tobacco component, did not induce noticeable effects on cockroach behavior. Both TSP extract and nicotine were shown to be phagostimulants. Olfactometry assays that measured odor-mediated insect behavior demonstrated that male B. germanica did not choose TSP-extract-treated food even when attempts were made specifically to train them via this modality. These results support a hypothesis that B. germanica needs to consume TSP-containing food to show a clear preference for this stimulus and that gustatory mechanisms are involved due to compounds present in the TSP extract.


Assuntos
Blattellidae/efeitos dos fármacos , Estimulantes Ganglionares/farmacologia , Nicotina/farmacologia , Olfato , Tabagismo , Animais , Condicionamento Clássico , Modelos Animais de Doenças , Comportamento Alimentar/efeitos dos fármacos , Masculino , Olfatometria
2.
J Membr Biol ; 215(2-3): 75-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17437145

RESUMO

Neem oil is a natural product obtained from the seeds of the tree Azadirachta indica. In this report, we investigate the alterations of the biophysical properties of the plasma membrane caused by treatment with the nonterpenoid fraction of neem oil that we defined as methanolic extract (MEX). The dose-response effect was evaluated and a MEX-dependent cytoxicity evidenced. The effect of MEX on the plasma membrane was studied by a well-established dielectric spectroscopy technique: electrorotation, which allows single-cell analysis. Our results show a structural/functional alteration of the plasma membrane with an evident increase of specific capacitance and conductance. The biological implications of this effect are discussed.


Assuntos
Azadirachta/química , Membrana Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Sementes/química , Animais , Membrana Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Capacitância Elétrica , Fibroblastos/citologia , Fibroblastos/fisiologia , Glicerídeos/química , Glicerídeos/farmacologia , Metanol/química , Camundongos , Extratos Vegetais/química , Terpenos/química , Terpenos/farmacologia
3.
Mol Cell Biochem ; 287(1-2): 69-77, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16652209

RESUMO

Neem oil is a natural product obtained from the seeds of the tree Azadirachta indica. Its composition is very complex and the oil exhibits a number of biological activities. The most studied component is the terpenoid azadirachtin which is used for its insecticidal and putative antimicrobial properties. In this report we investigate the biological activity of partially purified components of the oil obtained from A. indica. We show that the semi-purified fractions have moderate to strong cytotoxicity. However, this is not attributable to azadirachtin but to other active compounds present in the mixture. Each fraction was further purified by appropriate extraction procedures and we observed a differential cytotoxicity in the various sub-fractions. This led us to investigate the mode of cell death. After treatment with the oil fractions we observed positivity to TUNEL staining and extensive internucleosomal DNA degradation both indicating apoptotic death. The anti-proliferative properties of the neem oil-derived compounds were also assayed by evaluation of the nuclear PCNA levels (Proliferating Cell Nuclear Antigen). PCNA is significantly reduced in cells treated with a specific fraction of neem oil. Finally, our results strongly suggest a possible involvement of the mitochondrial pathway in the apoptotic death.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Azadirachta/química , Proliferação de Células/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Linhagem Celular , Fracionamento Químico , Fibroblastos/citologia , Glicerídeos/química , Glicerídeos/farmacologia , Camundongos , Mitocôndrias , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Sementes/química , Terpenos/química , Terpenos/farmacologia
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