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1.
Toxicol Appl Pharmacol ; 425: 115600, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34081940

RESUMO

Among postmenopausal women with estrogen receptor-positive breast cancer, more than 80% receive hormone therapy including aromatase inhibitors (AIs). Half of them develop chronic arthralgia - characterized by symmetric articular pain, carpal tunnel syndrome, morning stiffness, myalgia and a decrease in grip strength - which is associated with treatment discontinuation. Only a few animal studies have linked AI treatment to nociception, and none to arthralgia. Thus, we developed a new chronic AI-induced nociceptive disorder model mimicking clinical symptoms induced by AIs, using subcutaneous letrozole pellets in ovariectomized (OVX) rats. Following plasma letrozole dosage at the end of the experiment (day 73), only rats with at least 90 ng/ml of letrozole were considered significantly exposed to letrozole (OVX + high LTZ group), whereas treated animals with less than 90 ng/ml were pooled in the OVX + low LTZ group. Chronic nociceptive disorder set in rapidly and was maintained for more than 70 days in the OVX + high LTZ group. Furthermore, OVX + high LTZ rats saw no alteration in locomotion, myalgia or experimental anxiety during this period. Bone parameters of the femora were significantly altered in all OVX rats compared to Sham+vehicle pellet. A mechanistic analysis focused on TRPA1, receptor suspected to mediate AI-evoked pain, and showed no modification in its expression in the DRG. This new long-lasting chronic rat model, efficiently reproduces the symptoms of AI-induced nociceptive disorder affecting patients' daily activities and quality-of-life. It should help to study the pathophysiology of this disorder and to promote the development of new therapeutic strategies.


Assuntos
Inibidores da Aromatase/toxicidade , Modelos Animais de Doenças , Letrozol/toxicidade , Nociceptividade/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Doença Crônica , Feminino , Gânglios Espinais , Regulação da Expressão Gênica/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Sprague-Dawley
2.
Subst Abus ; 42(4): 706-715, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33320801

RESUMO

Background: Community pharmacists are among the frontline health professionals who manage patients with an opioid-related disorder (ORD). Pharmacists frequently have a negative attitude toward these patients, which could have a negative impact on their management. However, education on ORD may improve the attitude of future healthcare professionals. This cross-sectional study aimed to assess French pharmacy students' perceptions of ORD. Methods: This online survey was performed by emails sent to French pharmacy schools (between January 14, 2019 and May 31, 2019). The primary outcome was the perception (visual analogic scale) of ORD as a disease, the roles of community pharmacies (delivery of opioid agonist therapy-OAT and harm reduction kits), and the efficacy of OAT. The secondary outcomes assessed professional experience, university experience of and education on ORD, and the individual characteristics of students. Results: Among the 1,994 students included, 76.3% perceived ORD as a disease and felt that it was normal for pharmacists to deliver OAT (78.9%) and harm reduction kits (74.6%). However, only 46.9% perceived OAT as being effective. Multivariable analyses showed that females had a more positive perception in recognizing ORD as a disease. The progression through university years increased the positive perception of ORD as a disease and the delivery of OAT and harm reduction kits by pharmacists. Education on substance-related disorders had no impact on any scores. Students who had already delivered OAT had a negative perception of their efficacy. The students who had already performed pharmacy jobs or traineeships had a negative perception of harm reduction kit delivery. Conclusion: Education on substance-related disorders had no impact on students' perceptions. It seemed that the maturity acquired through university years had a stronger impact on the students' perceptions of ORD. Efforts must be made to improve our teaching methods and reinforce the confidence of students in the roles of community pharmacists.


Assuntos
Educação em Farmácia , Transtornos Relacionados ao Uso de Opioides , Estudantes de Farmácia , Estudos Transversais , Educação em Farmácia/métodos , Feminino , Humanos , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Percepção , Farmacêuticos , Inquéritos e Questionários
3.
J Cell Physiol ; 232(1): 101-9, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27028718

RESUMO

Leptin, a pleiotropic adipokine, is known as a regulator of food intake, but it is also involved in inflammation, immunity, cell proliferation, and survival. Leptin receptor is integrated inside cholesterol-rich microdomains called lipid rafts, which, if disrupted or destroyed, could lead to a perturbation of lytic mechanism. Previous studies also reported that leptin could induce membrane remodeling. In this context, we studied the effect of membrane remodeling in lytic activity modulation induced by leptin. Thus, primary mouse splenocytes were incubated with methyl-ß-cyclodextrin (ß-MCD), a lipid rafts disrupting agent, cholesterol, a major component of cell membranes, or ursodeoxycholic acid (UDCA), a membrane stabilizer agent for 1 h. These treatments were followed by splenocyte incubation with leptin (absence, 10 and 100 ng/ml). Unlike ß-MCD or cholesterol, UDCA was able to block leptin lytic induction. This result suggests that leptin increased the lytic activity of primary spleen cells against syngenic EO771 mammary cancer cells independently from lipid rafts but may involve membrane fluidity. Furthermore, natural killer cells were shown to be involved in the splenocyte lytic activity. To our knowledge it is the first publication in primary culture that provides the link between leptin lytic modulation and membrane remodeling. J. Cell. Physiol. 232: 101-109, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Leptina/metabolismo , Microdomínios da Membrana/metabolismo , Baço/metabolismo , Animais , Células Cultivadas , Colesterol/metabolismo , Feminino , Células Matadoras Naturais/metabolismo , Camundongos Endogâmicos C57BL , beta-Ciclodextrinas/metabolismo
4.
J Appl Toxicol ; 37(6): 732-746, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27896850

RESUMO

The easy-to-use in vivo model, zebrafish larva, is being increasingly used to screen chemical-induced hepatotoxicity, with a good predictivity for various mechanisms of liver injury. However, nothing is known about its applicability in exploring the mechanism called membrane remodeling, depicted as changes in membrane fluidity or lipid raft properties. The aim of this study was, therefore, to substantiate the zebrafish larva as a suitable in vivo model in this context. Ethanol was chosen as a prototype toxicant because it is largely described, both in hepatocyte cultures and in rodents, as capable of inducing a membrane remodeling leading to hepatocyte death and liver injury. The zebrafish larva model was demonstrated to be fully relevant as membrane remodeling was maintained even after a 1-week exposure without any adaptation as usually reported in rodents and hepatocyte cultures. It was also proven to exhibit a high sensitivity as it discriminated various levels of cytotoxicity depending on the extent of changes in membrane remodeling. In this context, its sensitivity appeared higher than that of WIF-B9 hepatic cells, which is suited for analyzing this kind of hepatotoxicity. Finally, the protection afforded by a membrane stabilizer, ursodeoxycholic acid (UDCA), or by a lipid raft disrupter, pravastatin, definitely validated zebrafish larva as a reliable model to quickly assess membrane remodeling involvement in chemical-induced hepatotoxicity. In conclusion, this model, compatible with a high throughput screening, might be adapted to seek hepatotoxicants via membrane remodeling, and also drugs targeting membrane features to propose new preventive or therapeutic strategies in chemical-induced liver diseases. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Larva/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Microdomínios da Membrana/efeitos dos fármacos , Modelos Biológicos , Peixe-Zebra , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Etanol/toxicidade , Humanos , Células Híbridas , Larva/metabolismo , Fígado/metabolismo , Fígado/patologia , Microdomínios da Membrana/patologia , Microscopia de Fluorescência , Estresse Oxidativo/efeitos dos fármacos , Pravastatina/farmacologia , Ratos , Ácido Ursodesoxicólico/farmacologia
5.
Biomed Pharmacother ; 149: 112915, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35635358

RESUMO

BACKGROUND: Donepezil, a cholinesterase inhibitor approved in Alzheimer's disease, has demonstrated analgesic and preventive effects in animal models of oxaliplatin-induced neuropathy. To improve the clinical interest of donepezil for the management and prevention of chemotherapy-induced peripheral neuropathy (CIPN), a broader validation is required in different animal models of CIPN. METHODS: using rat models of CIPN (bortezomib, paclitaxel, and vincristine), the analgesic and preventive efficacies of donepezil were evaluated on tactile, cold and heat hypersensitivities. The involvement of muscarinic M2 acetylcholine receptors (m2AChRs) in analgesic effects was investigated at the spinal level. The absence of interference of donepezil with the cytotoxic effect of chemotherapy has been controlled in cancer cell lines. RESULTS: the analgesic efficacy of donepezil was demonstrated for all CIPN models, mainly on tactile hypersensitivity (maximal efficacy at 60 min, p < 0.05 vs. vehicle group). This effect was suppressed by an intrathecal injection of methoctramine (m2AChR antagonist). Regarding preventive effects, donepezil limited tactile hypersensitivity induced by paclitaxel, but not for other CIPN models. Donepezil did not modify the viability of cancer cells or the efficacy of anticancer drugs. CONCLUSIONS: donepezil had a broad analgesic effect on animal models of CIPN and this effect involved spinal m2AChRs. This work validates the repositioning of donepezil in the management of CIPN.


Assuntos
Antineoplásicos , Leucemia Mieloide Aguda , Doenças do Sistema Nervoso Periférico , Acetilcolina , Analgésicos/efeitos adversos , Animais , Antineoplásicos/toxicidade , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Donepezila , Modelos Animais , Paclitaxel/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Doenças do Sistema Nervoso Periférico/prevenção & controle , Ratos , Receptor Muscarínico M2 , Receptores Muscarínicos
6.
Eur J Med Chem ; 244: 114809, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36208509

RESUMO

Vascular-disrupting agents (VDA) specifically target established neovasculature which results in vascular shutdown. This therapeutic strategy could improve the outcome of pathologies involving aberrant angiogenesis. Although several classes of VDA exist, inhibitors of tubulin assembly (ITA) represent the main category. A series of 21 conformationnally-restricted analogues of E7010, a known ITA-VDA, were designed and synthesised as novel inhibitors of tubulin assembly (ITA) and vascular-disrupting agents (VDA). Among them, indole 4j exhibited good potency against HUVEC and HIG-82 cell lines, as well as a good ability to inhibit tubulin assembly. Furthermore, indole 4j reduced HUVEC migration in a dose-dependent manner, indicating a vascular disrupting activity comparable to that of the gold standard, Combretastatin A4 (CA4).


Assuntos
Antineoplásicos , Tubulina (Proteína) , Tubulina (Proteína)/metabolismo , Linhagem Celular Tumoral , Moduladores de Tubulina , Antineoplásicos/farmacologia , Indóis/farmacologia , Inibidores da Angiogênese/farmacologia
7.
Free Radic Biol Med ; 160: 246-262, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-32791186

RESUMO

A growing body of evidences indicate the major role of extracellular vesicles (EVs) as players of cell communication in the pathogenesis of liver diseases. EVs are membrane-enclosed vesicles released by cells into the extracellular environment. Oxidative stress is also a key component of liver disease pathogenesis, but no role for hepatocyte-derived EVs has yet been described in the development of this process. Recently, some polycyclic aromatic hydrocarbons (PAHs), widespread environmental contaminants, were demonstrated to induce EV release from hepatocytes. They are also well-known to trigger oxidative stress leading to cell death. Therefore, the aim of this work was to investigate the involvement of EVs derived from PAHs-treated hepatocytes (PAH-EVs) in possible oxidative damages of healthy recipient hepatocytes, using both WIF-B9 and primary rat hepatocytes. We first showed that the release of EVs from PAHs -treated hepatocytes depended on oxidative stress. PAH-EVs were enriched in proteins related to oxidative stress such as NADPH oxidase and ferritin. They were also demonstrated to contain more iron. PAH-EVs could then induce oxidative stress in recipient hepatocytes, thereby leading to apoptosis. Mitochondria and lysosomes of recipient hepatocytes exhibited significant structural alterations. All those damages were dependent on internalization of EVs that reached lysosomes with their cargoes. Lysosomes thus appeared as critical organelles for EVs to induce apoptosis. In addition, pro-oxidant components of PAH-EVs, e.g. NADPH oxidase and iron, were revealed to be necessary for this cell death.


Assuntos
Vesículas Extracelulares , Hidrocarbonetos Policíclicos Aromáticos , Animais , Vesículas Extracelulares/metabolismo , Hepatócitos , Ferro/metabolismo , Estresse Oxidativo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Ratos
8.
Bull Cancer ; 105(11): 1020-1032, 2018 Nov.
Artigo em Francês | MEDLINE | ID: mdl-30244980

RESUMO

Chemotherapy-induced peripheral neuropathy (CIPN) is common with specific semiological characteristics. When CIPN appears, there are many difficulties in guaranteeing sustained treatment, especially with optimal protocol. Moreover, CIPN have bad repercussions on quality of life after cancer disease. In this article, we have achieved a current state of CIPN and try to report details about semiological characteristics and topography. We have also produced some epidemiological data. Nonetheless, we have not voluntarily introduced treatment because it will be the topic of further work.


Assuntos
Antineoplásicos/efeitos adversos , Neoplasias/tratamento farmacológico , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Bortezomib/efeitos adversos , Humanos , Imunossupressores/efeitos adversos , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/epidemiologia , Compostos de Platina/efeitos adversos , Qualidade de Vida , Avaliação de Sintomas , Taxoides/efeitos adversos , Talidomida/efeitos adversos , Alcaloides de Vinca/efeitos adversos
9.
Front Pharmacol ; 9: 725, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30065649

RESUMO

Background: The use of psychotropic medications and illegal drugs is a worldwide public health issue, leading to addiction, psychiatric and somatic disorders, and death. Pharmacy students are more exposed to psychotropic medications than other students (non-medical), which could lead to an overuse. The main objective of this study was to assess the prevalence of psychotropic drug use (medications and illegal drugs) by French pharmacy students, by carrying out a nationwide cross-sectional study. The relation of these medications and illegal drug use with several comorbidities and academic achievement was also assessed. Methods: This online survey was performed by emails sent to all French pharmacy faculties over a period of 66 days (March 16, 2016 to May 20, 2016). The survey assessed the prevalence of uses of psychotropic medications and illegal drugs during the last 3 months. These uses were compared to student characteristics (personal and university) and comorbidities (anxiety, depression, stress, and fatigue). Results: Of the 2,609 questionnaires received, 2,575 were completed and useable for the analysis. Among French pharmacy students and during the 3 last months, 9.4% have used psychotropic medications, 21.5% illegal drugs and 3.3% both psychotropic medications and illegal drugs. Psychotropic medications were used in the cases of a medical prescription (49.0%), a self-medication (42.4%) or a non-medical intent (26.3%). Stress scores of the last 7 days were higher for psychotropic medication users compared to non-users and illegal drug users. Proportions of anxiety and depression at the time of answer were higher for psychotropic medication users than for non-users and illegal drug users. Fatigue scores of the last 7 days were lower for illegal drug users compared to non-users and self-medicated students. Annual average marks of the last year, attendance and perception of study difficulty were lower for illegal drug users than for non-users. Conclusion: French pharmacy students were less exposed to psychotropic medications and illegal drugs than the general French population. However, in comparison to other students in other countries, the use of psychotropic medications seemed to be lower, but with a proportionally higher use of anxiety/sedative medications and a lower use of opioid medications.

10.
Front Pharmacol ; 8: 86, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28286483

RESUMO

Neurotoxic anticancer drugs, such as platinum-based anticancer drugs, taxanes, vinca alkaloids, and proteasome/angiogenesis inhibitors are responsible for chemotherapy-induced peripheral neuropathy (CIPN). The health consequences of CIPN remain worrying as it is associated with several comorbidities and affects a specific population of patients already impacted by cancer, a strong driver for declines in older adults. The purpose of this review is to present a comprehensive overview of the long-term effects of CIPN in cancer patients and survivors. Pathophysiological mechanisms and risk factors are also presented. Neurotoxic mechanisms leading to CIPNs are not yet fully understood but involve neuronopathy and/or axonopathy, mainly associated with DNA damage, oxidative stress, mitochondria toxicity, and ion channel remodeling in the neurons of the peripheral nervous system. Classical symptoms of CIPNs are peripheral neuropathy with a "stocking and glove" distribution characterized by sensory loss, paresthesia, dysesthesia and numbness, sometimes associated with neuropathic pain in the most serious cases. Several risk factors can promote CIPN as a function of the anticancer drug considered, such as cumulative dose, treatment duration, history of neuropathy, combination of therapies and genetic polymorphisms. CIPNs are frequent in cancer patients with an overall incidence of approximately 38% (possibly up to 90% of patients treated with oxaliplatin). Finally, the long-term reversibility of these CIPNs remain questionable, notably in the case of platinum-based anticancer drugs and taxanes, for which CIPN may last several years after the end of anticancer chemotherapies. These long-term effects are associated with comorbidities such as depression, insomnia, falls and decreases of health-related quality of life in cancer patients and survivors. However, it is noteworthy that these long-term effects remain poorly studied, and only limited data are available such as in the case of bortezomib and thalidomide-induced peripheral neuropathy.

11.
PLoS One ; 12(8): e0182956, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28800612

RESUMO

BACKGROUND: Work-related stress and burnout syndromes are unfortunately common comorbidities found in health professionals. However, burnout syndrome has only been partly and episodically assessed for community pharmacists whereas these professionals are exposed to patients' demands and difficulties every day. Prevalence of burnout, associated comorbidities and coping strategies were assessed in pharmacy teams (pharmacists and pharmacy technicians) in French community pharmacies. METHODS: This online survey was performed by emails sent to all French community pharmacies over 3 months. The survey assessed the prevalence of burnout (Maslach Burnout Inventory-MBI-questionnaire), anxiety, depression and strategies for coping with work-related stress. RESULTS: Of the 1,339 questionnaires received, 1,322 were completed and useable for the analysis. Burnout syndrome was detected in 56.2% of respondents and 10.5% of them presented severe burnout syndrome. Severe burnout syndrome was significantly associated with men, large urban areas and the number of hours worked. Depression and anxiety were found in 15.7% and 42.4% of respondents, respectively. These co-morbidities were significantly associated with severe burnout syndrome. Higher MBI scores were significantly associated with medical consultations and medicinal drug use. Conversely, respondents suffering from burnout syndrome declared they resorted less to non-medical strategies to manage their work-related stress (leisure, psychotherapy, holidays and time off). CONCLUSION: This study demonstrated that community pharmacists and pharmacy technicians presented high prevalence of burnout syndrome, such as many healthcare professionals. Unfortunately, burnout syndrome was associated with several comorbidities (anxiety, depression and alcohol abuse) and the consumption of health resources. The psychological suffering of these healthcare professionals underlines the necessity to deploy a strategy to detect and manage burnout in community pharmacy.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Ansiedade/epidemiologia , Esgotamento Profissional/epidemiologia , Depressão/epidemiologia , Farmacêuticos/psicologia , Técnicos em Farmácia/psicologia , Estresse Psicológico/epidemiologia , Adaptação Psicológica/fisiologia , Adulto , Consumo de Bebidas Alcoólicas/psicologia , Ansiedade/tratamento farmacológico , Ansiedade/economia , Ansiedade/psicologia , Esgotamento Profissional/tratamento farmacológico , Esgotamento Profissional/economia , Esgotamento Profissional/psicologia , Comorbidade , Estudos Transversais , Depressão/tratamento farmacológico , Depressão/economia , Depressão/psicologia , Feminino , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Farmácias , Prevalência , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/economia , Inquéritos e Questionários , Recursos Humanos
12.
PeerJ ; 5: e3973, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29085764

RESUMO

BACKGROUND: Like other health professionals, community pharmacists are exposed to stress factors (being efficient, avoiding mistakes and bearing emotional load), but they are also under the pressure of entrepreneurial responsibilities. The main objective was to assess the level of work-related stress in French community pharmacies. The other objectives of the study were to assess the associated comorbidities and causes of work-related stress. METHODS: This observational cross-sectional study was sent to all French community pharmacies by email. The survey was anonymous and designed to collect the following items: socio-demographic factors, professional status, characteristics of community pharmacy, work-related stress (visual analogic scale-VAS), fatigue (VAS), sleep disturbances (questions), anxiety and depression symptoms (hospital anxiety and depression scale), medical consultation for work-related stress, medication use for work related stress, psychoactive drug-use and causes of work-related stress. Participants were included in the survey if they were pharmacists (owner or assistant) or pharmacy technicians working in a community pharmacy at the time of the survey. Exclusion criteria were defined as follows: pharmacy students or other professionals involved in a community pharmacy (e.g. dietician, beautician) and lack of professional status information. There was no age limitation. RESULTS: After three months of data collection, 1,339 participants answered the survey and 1,272 participants were included in conformity with the inclusion and exclusion criteria, and to avoid missing data on the primary endpoint. Work-related stress was detected in 32.8% (417/1,272) of individuals (scores ≥70/100). Men were significantly more affected than women and there was no difference between professional statuses and no relation with the age of the participants. Work-related stress was significantly associated with anxiety, depression, fatigue, sleep disturbances, medical consultations, medication use, alcohol consumption above the WHO recommendations for men and psychoactive drug use. Three causes of stress were clearly identified and related to stress levels, workload, working atmosphere and deterioration of work quality. However, causes of work-related stress were significantly different among professionals, for example: entrepreneurial burden for pharmacists-in-charge and workload for employees (assistant pharmacists and pharmacy technicians). DISCUSSION: Work-related stress has a very strong impact in French community pharmacies. This stress was associated with several comorbidities and induces health resource consumption. Several causes of work-related stress have been identified such as workload, working atmosphere and deterioration of work quality; however, these causes could be detected and managed to improve stress levels. We recommend developing individual and organizational stress management in French community pharmacies.

13.
Free Radic Biol Med ; 72: 11-22, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24681337

RESUMO

Several epidemiologic studies have shown an interactive effect of heavy smoking and heavy alcohol drinking on the development of hepatocellular carcinoma. It has also been recently described that chronic hepatocyte death can trigger excessive compensatory proliferation resulting later in the formation of tumors in mouse liver. As we previously demonstrated that both benzo[a]pyrene (B[a]P), an environmental agent found in cigarette smoke, and ethanol possess similar targets, especially oxidative stress, to trigger death of liver cells, we decided to study here the cellular and molecular mechanisms of the effects of B[a]P/ethanol coexposure on cell death. After an 18-h incubation with 100nM B[a]P, primary rat hepatocytes were supplemented with 50mM ethanol for 5 or 8h. B[a]P/ethanol coexposure led to a greater apoptotic cell death that could be linked to an increase in lipid peroxidation. Plasma membrane remodeling, as depicted by membrane fluidity elevation and physicochemical alterations in lipid rafts, appeared to play a key role, because both toxicants acted with specific complementary effects. Membrane remodeling was shown to induce an accumulation of lysosomes leading to an important increase in low-molecular-weight iron cellular content. Finally, ethanol metabolism, but not that of B[a]P, by providing reactive oxygen species, induced the ultimate toxic process. Indeed, in lysosomes, ethanol promoted the Fenton reaction, lipid peroxidation, and membrane permeabilization, thereby triggering cell death. To conclude, B[a]P exposure, by depleting hepatocyte membrane cholesterol content, would constitute a favorable ground for a later toxic insult such as ethanol intoxication. Membrane stabilization of both plasma membrane and lysosomes might be a potential target for further investigation considering cytoprotective strategies.


Assuntos
Benzo(a)pireno/toxicidade , Membrana Celular/efeitos dos fármacos , Etanol/toxicidade , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Carcinógenos/toxicidade , Depressores do Sistema Nervoso Central/toxicidade , Hepatócitos/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Microscopia Eletrônica de Transmissão , Ratos , Ratos Sprague-Dawley
14.
Food Chem Toxicol ; 60: 286-96, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23907024

RESUMO

Previously, we demonstrated that eicosapentaenoic acid enhanced ethanol-induced oxidative stress and cell death in primary rat hepatocytes via an increase in membrane fluidity and lipid raft clustering. In this context, another n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), was tested with a special emphasis on physical and chemical alteration of lipid rafts. Pretreatment of hepatocytes with DHA reduced significantly ethanol-induced oxidative stress and cell death. DHA protection could be related to an alteration of lipid rafts. Indeed, rafts exhibited a marked increase in membrane fluidity and packing defects leading to the exclusion of a raft protein marker, flotillin. Furthermore, DHA strongly inhibited disulfide bridge formation, even in control cells, thus suggesting a disruption of protein-protein interactions inside lipid rafts. This particular spatial organization of lipid rafts due to DHA subsequently prevented the ethanol-induced lipid raft clustering. Such a prevention was then responsible for the inhibition of phospholipase C-γ translocation into rafts, and consequently of both lysosome accumulation and elevation in cellular low-molecular-weight iron content, a prooxidant factor. In total, the present study suggests that DHA supplementation could represent a new preventive approach for patients with alcoholic liver disease based upon modulation of the membrane structures.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Etanol/toxicidade , Hepatócitos/efeitos dos fármacos , Microdomínios da Membrana/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Microdomínios da Membrana/metabolismo , Proteínas de Membrana/metabolismo , Peso Molecular , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipases Tipo C/metabolismo
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