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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

The antidepressant properties of selected methylene blue analogues / Anzelle Delport

Delport, Anzelle January 2014 (has links)
The shortcomings of current antidepressant agents prompts the design of novel multimodal antidepressants and the identification of new antidepressant targets, especially those located at sub-cellular level. Such antidepressants should possess improved response rates as well as safety profiles. Methylene blue (MB) is reported to possess diverse pharmacological actions and is attracting increasing attention for the treatment of a variety of disorders including Alzheimer’s disease, bipolar disorder, anxiety and depression. MB acts on both monoamine oxidase (MAO) and the nitric oxide (NO)-cGMP pathway, and possesses antidepressant activity in rodents. The principal goal of this study was to design a close structural analogue of MB and to evaluate the effects of these structural changes on MAO inhibition, a well-known antidepressant target. Furthermore, MAO inhibition is also responsible for cardiovascular toxicity in clinically used MAOI inhibitors. For this purpose we investigated the antidepressant properties of the synthetic MB analogue (ethyl-thioniniumchloride; ETC) as well as azure B, the major metabolite of MB, in the forced swim test (FST). ETC was synthesized with a high degree of purity from diethyl-p-phenylenediamine with 6% yield. ETC was firstly evaluated as a potential inhibitor of recombinant human MAO-A and MAO-B. Azure B and ETC were evaluated over a dosage range of 4-30 mg/kg for antidepressant-like activity in the acute FST in rats, and the results were compared to those obtained with saline, imipramine (15 mg/kg) and MB (15 mg/kg) treated rats. Locomotor activity was evaluated to ensure that changes in swim motivation are based on antidepressant response and not due to an indirect effect of the drug on locomotor activity. The results document that ETC inhibits MAO-A and MAO-B with IC50 values of 0.51 μM and 0.592 μM, respectively. Furthermore, ETC inhibits MAO-A and MAO-B reversibly, while the mode of inhibition is most likely competitive. In the acute FST, azure B and ETC were more effective than imipramine and MB in reversing immobility, without inducing locomotor effects. Azure B and ETC increased swimming behaviour during acute treatment, which is indicative of enhanced serotonergic neurotransmission. Azure B and ETC did not affect noradrenergicmediated climbing behaviour. These results suggest that azure B may be a contributor to the antidepressant effect of MB, and acts via increasing serotonergic transmission. Secondly, small structural changes made to MB do not abolish its antidepressant effect even though ETC is a less potent MAO-A inhibitor than MB. / MSc (Pharmaceutical Chemistry), North-West University, Potchefstroom Campus, 2014
62

The role of the NO-cGMP pathway as a putative target in antidepressant action / Renché Retief

Retief, Renché January 2004 (has links)
Depressive disorders are among the most frequent psychiatric diseases in the Western world with prevalence between 9% and 18%. Poor compliance and inappropriate antidepressant discontinuation invokes long-term morbidity, and appear linked to hippocampal shrinkage. Despite major advances in pharmacological treatment of the illness over the past 3040 years, currently available agents have distinct shortfalls both in clinical efficacy and in maintenance of response. This implies a greater long-term morbidity with significant impact on the patient, the patient's family as well as economic implications to health care managers and providers. The major reason for this state of affairs is our poor understanding of the neurobiology of depression and hence, of antidepressant (AD) action. AD drugs are thus not addressing the crucial neurobiological target underlying the illness, and new strategies and treatments are urgently needed. In recent years, depression has been associated with disturbances in excitotoxic glutamatergic activity, yet this has not been systematically evaluated. While the role of neurotransmitters such as serotonin, noradrenaline and dopamine has been extensively studied, new evidence suggests a role for the unique neurotransmitter nitric oxide (NO). Nitric oxide (NO), is activated by glutamatergic systems in various limbic and other regions of the brain, and has recently also been implicated in anxiety and affective disorders. Of special interest is the putative role of NO in cellular memory, synaptic plasticity and cell survival, all-important processes in the neuropathology and neurodevelopment of depression. Recent clinical studies have provided evidence of the role of the NO-pathway in depression, while preclinical studies have demonstrated the anxiolytic and antidepressant actions of nitric oxide synthase (NOS)-inhibitors. Moreover, NO interacts with other classical transmitters that have a regulatory role on mood, particularly the monoamines, as well as glutamate and gammaaminobutyric acid (GABA). In the current study the role of the NO-cGMP pathway in AD action was investigated, after chronic imipramine (IMI) and after IMI withdrawal, using a learned helplessness paradigm. Behavioural changes, hippocampal NOS activity and cGMP accumulation was determined together with pharmacological manipulation of the NO-cGMP pathway. Chronic IMI, 15 mg/kg/day intraperitoneal (ip) administration induced a pronounced reduction in swim immobility time in the forced swim test (FST), with no effect on horizontal or vertical locomotor activity. These behavioural changes were accompanied by a significant reduction in NOS enzyme activity and cGMP accumulation. In order to confirm the involvement of the NO-cGMP pathway in the AD action of IMI, chronic (3 weeks) IMI treatment was followed by an acute withdrawal of 7 days. Acute withdrawal, after chronic IMI treatment, resulted in a significant increase in swim immobility time and an increase in NOS enzyme activity and cGMP levels. In fact, NOS activity was raised above that of control, not just higher than the effect of chronic IMI. In order to assess the possible role of the NMDA-NO-cGMP pathway in AD withdrawal, the NMDA receptor antagonist, memantine, and the NOS/guanylyl cyclase (GC) inhibitor, methylene blue (MB), were administered during the 7 day IMI withdrawal period. Memantine (5 mg/kg/d ip), during the 7 day IMI withdrawal period, significantly reversed the increase in immobility time evoked after IMI withdrawal. This was accompanied by a significant reduction in NOS enzyme activity and a tendency to decrease cGMP levels. This data confirms that the antidepressant action of IMI, as well as IMI withdrawal, is associated with actions on the NMDA-GIu-NO-cGMP pathway. Particularly. IMI withdrawal evokes an increase in glutamate activity that is responsible for NOS activation. During the 7 day IMI withdrawal period, MB (15 mg/kg/d ip) also significantly reversed the increased immobility time after IMI withdrawal and was accompanied by a tendency to decrease NOS enzyme activity and cGMP levels in the rat hippocampus, however statistical significance was not reached. Although not emphatic, this data implies a possible role of the NO-cGMP pathway in AD action and AD withdrawal. In order to determine whether the observed IMI withdrawal effects on the NO-cGMP pathway may occur through an initial destabilisation in the serotonergic system, the 5-HT2a/2c receptor antagonist, ritanserin (4 mg/kg/d ip), was administered during the IMI withdrawal period. These studies revealed that antidepressant withdrawal evokes an increase in 5-HT2-mediated activity, and that antidepressant-induced NOS activation after withdrawal has its origin in serotonergic hyperactivity. Clearly, this is supportive of a distinct relationship between the NO and serotonergic system in antidepressant response. On its own, ritanserin was found to increase NOS and cGMP levels, yet during IMI withdrawal this response was lost, suggesting that IMI withdrawal alters the response to a 5-HT2a/2c receptor antagonist, which may have major clinical implications. In conclusion, the AD action of IMI, as well as chronic IMI withdrawal, involves actions on the NO-cGMP pathway. Withdrawal of ADS is associated with a loss of AD efficacy together with an increase in release of NO and cGMP. The NMDA antagonist, memantine, and the NOS/GC inhibitor, MB, reversed these responses therefore suggesting that the NMDA-GIu-NO-cGMP pathway may be a new putative target in understanding the neurobiology of AD action. Finally, NOS activation following withdrawal suggest that inappropriate withdrawal during the treatment of depression may mediate neurodegenerative pathology observed in recurrent depression, possibly by severely increased hippocampal NOS activity which is toxic to neurons. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2005.
63

Electrophysiological Studies on the Impact of Repeated Electroconvulsive Shocks on Catecholamine Systems in the Rat Brain

Tsen, Peter 10 June 2011 (has links)
Electroconvulsive therapy (ECT) effectively treats depression by administration of repeated seizure-inducing electrical stimuli. Sprague-Dawley rats were administered 6 electroconvulsive shocks (ECS) over 2 weeks, and in vivo single unit extracellular electrophysiological activity was recorded after 48 hours. Overall firing activity in the locus coeruleus and ventral tegmental area was unchanged, suggesting the therapeutic efficacy of ECT may not be attributed to increased norepinephrine and dopamine release. There were more spontaneously active neurons in the substantia nigra pars compacta (SNc), indicating greater dopamine tone in the nigrostriatal motor pathway, which may contribute to alleviation of psychomotor retardation. In the facial motor nucleus (FMN), locally administered norepinephrine, but not serotonin, facilitated greater glutamate-induced firing, which may contribute to improved facial motricity. Current results indicate that repeated ECS enhances postsynaptic norepinephrine neurotransmission in the FMN and SNc dopamine neurotransmission, which could represent the mechanism behind the alleviation of depressive symptoms including psychomotor retardation.
64

Voice of the drug interpreting medicalized disempowerment in women's narratives of depression /

Hoogen, Siri Rebecca. January 2006 (has links)
Thesis (M.A.)--Miami University, Dept. of Psychology, 2006. / Title from first page of PDF document. Includes bibliographical references (p. 44-56).
65

Obtenção de frações de valepotriatos através de fluido supercrítico e triagem psicofarmacológica de valeriana glechomifolia Meyer

Salles, Luisa de Andrade January 2010 (has links)
Espécies do gênero Valeriana são tradicionalmente utilizadas para tratar ansiedade, irritabilidade e desordens de sono. A Organização Mundial da Saúde indica o uso de preparações farmacêuticas como alternativa aos benzodiazepínicos para tratamento da ansiedade e insônia. Entre as substâncias ativas presentes no gênero Valeriana destacam-se os óleos voláteis, valepotriatos, flavonóides e lignanas. Entretanto, estudos farmacológicos com produtos isolados são escassos. Espécies nativas de Valeriana, que ocorrem no Rio Grande do Sul, têm sido estudadas em relação a sua composição química, sendo a espécie Valeriana glechomifolia a que possui maior teor de valepotriatos. Neste estudo, diferentes métodos de extração de valepotriatos foram comparados e extratos enriquecidos em valepotriatos foram testados em modelos animais de sedação, ansiedade e depressão. Valepotriatos isolados foram submetidos a ensaios de ligação a receptores benzodiazepínico e serotonérgico (5HT1A) e ensaios de atividade da enzima Na+K+ATPase. A extração por fluido supercrítico com dióxido de carbono (SCCO2) foi realizada em temperatura constante de 40 oC e pressões variáveis (90, 120, 150 e 200 bar) e demonstrou maior teor de valepotriatos que os métodos de extração por maceração em ultrassom e maceração Entre as diferentes pressões de extração utilizadas no método de SCCO2, o maior teor de valepotriatos foi apresentado pela fração obtida na pressão de 90 bar. Todos os extratos mostraram o mesmo perfil qualitativo de valepotriatos. Flavonóides também foram obtidos através de maceração por ultrassom em metanol. A dose letal mediana dos valepotriatos obtidos por maceração por ultrassom foi de 42±3 mg/kg, i.p. Esta mesma solução extrativa, na dose de 10 mg/kg, v.o. (gavage), foi inefetiva no labirinto em cruz elevado e tempo de sono barbitúrico, sugerindo a ausência de propriedades ansiolíticas e hipnótico-sedativas. Resultados similares foram obtidos com a solução extrativa enriquecida em flavonóides. Valtrato, acevaltrato, 1-b-acevaltrato, diavaltrato e o flavonóide codificado como B6 não apresentaram ligação ao sítio benzodiazepínico do complexo receptor GABAA, nem ao receptor serotonérgico (5HT1A) viii na faixa de concentração de 1-100 μM. Os valepotriatos inibiram a atividade da enzima Na+K+-ATPase na faixa de concentração micromolar. A fração de valepotriatos obtida por SCCO2 (10 mg/kg, gavage) foi efetiva no teste da natação forçada, sem interferir na atividade locomotora espontânea, sugerindo uma atividade do tipo antidepressiva. Em conclusão, a extração por fluido supercrítico com dióxido de carbono mostrou-se eficiente para a obtenção de frações enriquecidas em valepotriatos e estas substâncias representam uma nova classe química com atividade inibitória não seletiva da enzima Na+K+ATPase, e com atividade do tipo antidepressiva. / Species of the genus Valeriana are traditionally used to treat anxiety, irritability and sleep disorders. The World Health Organization indicates pharmaceutical preparations of V. officinalis as an alternative to benzodiazepine drugs for treating anxiety and insomnia. Volatile oil, valepotriates, flavonoids and lignan have been suggested as active substances of the Valeriana genus. However pharmacological studies on isolated compounds are scarce. Species of Valeriana native to Rio Grande do Sul have been studied regarding their chemical composition being Valeriana glechomifolia the species with highest valepotriate’ contents. In this study different methods of extraction of valepotriates from aerial parts of V. glechomifolia were compared, and valepotriate’ enriched extracts were tested in mice models of sedation, anxiety and depression. Isolated valepotriates were submitted to binding to benzodiazepine and 5HT1A receptors, and assayed for the Na+K+ATPase inhibitory activity. The extraction by supercritical carbon dioxide (SCCO2) was carried out at 40 oC under 90, 120, 150 or 200 bar affording higher valepotriates contents than maceration with dichloromethane and ultrasound. The highest valepotriates yielding was obtained with SCCO2 (40 oC , 90 bar). All extracts presented the same qualitative valepotriate’ profile. Flavonoids were also obtained from methanol extracts. The median lethal dose of valepotriates obtained by maceration was determined as 42±3 mg/kg, i.p. This valepotriate’ enriched extract (10 mg/kg, p.o., gavage) was ineffective in the elevated plus maze and barbiturate sleeping time tests suggesting that it does not present anxiolitic or hypnotic-sedative properties. Similar results were obtained with flavonoids’ enriched extract. Valtrate, acevaltrate, 1-b-acevaltrate, diavaltrate and the flavonoid named B6 did not bind to benzodiazepine site of receptor GABAA complex neither to serotonergic receptor (5HT1A) at 1-100 μM. The valepotriates inhibited the Na+K+ATPase activity at micromolar concentration range. The valepotriates fraction obtained by SCCO2 (10 mg/kg, gavage) was effective in the forced swimming test without interfering with the spontaneous locomotor activity suggesting that it presents an antidepressant-like activity. In conclusion the extraction by supercritical carbon dioxide is valuable to obtain valepotriates enriched fractions; and valepotriates seem to represent new chemical entities with no selective inhibitory activity of Na+K+ATPase, as well as with antidepressant-like activity.
66

Avaliação do envolvimento do sistema monoaminérgico na atividade antidepressiva de um extrato obtido por dióxido de carbono supercrítico de valeriana glechomifolia meyer / Evaluation of the monoaminergic system involvement in the antidepressantlike effect of a supercritical carbon dioxide Valeriana glechomifolia Meyer extract

Müller, Liz Girardi January 2011 (has links)
Espécies do gênero Valeriana são tradicionalmente utilizadas no tratamento de insônia e ansiedade. Valepotriatos constituem um importante grupo de metabólitos do gênero que contribui para os efeitos farmacológicos. Trabalhos recentes demonstraram a atividade do tipo antidepressiva de diversas espécies de Valeriana, como V. glechomifolia, nativa do Rio Grande Sul, o que representa uma nova abordagem para o emprego terapêutico do gênero. Objetivos: Investigar o envolvimento da neurotransmissão monoaminérgica na atividade antidepressiva de um extrato de V. glechomifolia obtido por dióxido de carbono supercrítico (SCCO2) e avaliar a influência do tempo e condições de armazenamento no teor de valepotriatos diênicos. Materiais e Métodos: Partes aéreas e subterrâneas de V. glechomifolia foram submetidas a SCCO2 e o extrato obtido foi armazenado (a - 20ºC) seco ou solubilizado em metanol. As concentrações de valepotriatos diênicos foram determinadas, durante 8 meses, através de cromatografia líquida de alta eficiência. A atividade do tipo antidepressiva foi avaliada em camundongos no teste da suspensão pela cauda (TSC) e da natação forçada (TNF). Para a investigação do envolvimento do sistema monoaminérgico, antagonistas de receptores de monoaminas e um inibidor da síntese de serotonina foram administrados. A interação do extrato com antidepressivos convencionais foi avaliada no TNF através da co-administração de doses sub-efetivas. Resultados e Conclusões: V. glechomifolia reduziu a imobilidade dos animais no TSC e TNF, confirmando o potencial antidepressivo. O efeito foi mediado pelos sistemas neurotransmissores noradrenérgico (receptor α2) e dopaminérgico (receptores D1 e D2), o que representa uma ação dual diferenciada. V. glechomifolia potencializou o efeito de imipramina, desipramina e bupropiona no TNF. Em ambas as condições de armazenamento do extrato, observaram-se conversão molecular de valepotriatos diênicos em valtrato. Houve formação de produtos de degradação somente quando o extrato foi armazenado em metanol. / Species of the genus Valeriana are traditionally used to treat sleep disorders and anxiety. Valepotriates represent an important group of metabolites that contribute to the pharmacological properties of the genus. Studies have demonstrated the antidepressant-like activity of Valeriana species, like V. glechomifolia, a south Brazil native species, representing a new approach to the therapeutic use of the genus. Objectives: To further investigate the antidepressant-like activity of a V. glechomifolia supercritical carbon dioxide (SCCO2) extract as well as to evaluate the influence of time and storage conditions on diene valepotriates content of this extract. Material and Methods: Aerial and subterranean parts of V. glechomifolia were submitted to SCCO2 and the extract was stored (at -20 ºC) dry or in methanol. Diene valepotriates concentrations were determined through 8 months by high efficiency liquid chromatography. The antidepressant-like activity was evaluated in mice forced swimming test (FST) or tail suspension test (TST). To investigate the involvement of the monoaminergic system in this effect, different groups of mice were pre-treated with monoamine receptors antagonists or an inhibitor of serotonin synthesis. The interaction of the extract with antidepressants was evaluated in the FST by mice co-administration of sub-effective doses. Results and Conclusions: V. glechomifolia was active in the FST and TST, confirming its antidepressant-like effect, which was impaired by adrenergic (α2) and dopaminergic D1 and D2 antagonists, representing a distinct dual action. V. glechomifolia potentiated the antidepressant-like effect of imipramine, desipramine and bupropione in the FST. In both conditions of extract storage, a molecular interconvertion of diene valepotriates into valtrate was observed. Degradation products formation occurred only when the extract was stored in methanol.
67

Tianeptina e neuroprogressão no transtorno bipolar

Kapczinski, Natalia Soncini January 2016 (has links)
O curso longitudinal do transtorno bipolar é altamente variável, mas um subconjunto de pacientes parece apresentar uma evolução progressiva associada a alterações cerebrais e comprometimento funcional. Em nosso primeiro artigo, discutimos a teoria da neuroprogressão no transtorno bipolar. Este conceito considera a resposta ao estresse que ocorre nos episódios de humor e déficits no funcionamento e cognição, bem como alterações neuroanatômicas nos estágios tardios da doença. Discutimos também refratariedade ao tratamento que pode ocorrer em alguns casos de transtorno bipolar. Foi executada uma busca na base de dados PubMed para artigos publicados em qualquer idioma até 04 de junho de 2016. Foram encontrados 315 resumos e 87 estudos foram incluídos em nossa revisão. Somos da opinião de que o uso de estratégias farmacológicas específicas e remediação funcional pode ser potencialmente útil em pacientes bipolares em estágios tardios. Novas abordagens analíticas que utilizam dados multimodais têm o potencial para ajudar na identificação de assinaturas de subgrupos de pacientes que irão desenvolver um curso neuroprogressivo. Com base em nossa hipótese de neuroprogressão, decidimos realizar um ensaio clínico randomizado com o antidepressivo tianeptina como tratamento adjuvante para o transtorno bipolar, a fim de melhorar o comprometimento funcional, desfechos clínicos e aumentar os níveis do Brain-Derived Neurothrofic Factor (BDNF). Tianeptina é um fármaco seguro, que atua sobre o sistema glutamatérgico e tem um efeito antidepressivo. Esse estudo teve como objetivo avaliar a eficácia e tolerabilidade da tianeptina como tratamento adjuvante para a depressão bipolar. Foi realizado um ensaio clínico duplo-cego randomizado de manutenção controlado por placebo com tianeptina 37,5 mg/dia. Os participantes (n = 161) tinham uma pontuação na Montgomery Asberg Depression Rating ≥12 no início do ensaio. Após oito semanas de tratamento com tianeptina na fase aberta, aqueles que responderam a tianeptina foram randomizados para o placebo ou tianeptina adjuvante. Os participantes foram recrutados na rede pública de saúde. Tempo para qualquer intervenção foi o desfecho primário do estudo. Mudanças nos sintomas de humor, funcionamento, ritmos biológicos, qualidade de vida, taxas de virada maníaca e níveis séricos de BDNF foram considerados como desfechos secundários. Houve uma diminuição importante nos sintomas depressivos, assim como melhoras no funcionamento, qualidade de vida e pontuações no ritmo biológico durante a fase aberta de tratamento com tianeptina por oito semanas. Durante as 24 semanas do ensaio duplo-cego randomizado e controlado por placebo, não houve diferença em relação ao desfecho primário: tempo para qualquer intervenção. Além disso, não houve diferenças significativas entre os grupos em relação aos sintomas de humor, funcionamento e níveis de BDNF. Tianeptina foi bem tolerada e não foi associada a virada maníaca em comparação com o placebo. Estes achados sugerem que tianeptina é um medicamento seguro e pode ser eficaz no tratamento da depressão bipolar aguda. No entanto, tianeptina não mostrou efeitos benéficos na fase de manutenção. Este é o primeiro ensaio clínico duplo-cego randomizado de manutenção e de longo prazo com antidepressivo no transtorno bipolar. / The longitudinal course of bipolar disorder is highly variable, and a subset of patients seems to present a progressive course associated with brain changes and functional impairment. In our first article, we discussed the theory of neuroprogression in bipolar disorder. This concept considers the systemic stress response that occurs within mood episodes and late-stage deficits in functioning and cognition as well as neuroanatomic changes. We also discuss treatment refractoriness that may take place in some cases of bipolar disorder. We searched PubMed for articles published in any language up to June 4th, 2016. We found 315 abstracts and included 87 studies in our review. We are of the opinion that the use of specific pharmacological strategies and functional remediation may be potentially useful in bipolar patients at late-stages. New analytic approaches using multimodal data hold the potential to help in identifying signatures of subgroups of patients who will develop a neuroprogressive course. Based on our hypothesis of neuroprogression, we decided to perform a randomized clinical trial with tianeptine as adjunctive treatment for bipolar disorder in order to improve functional impairment and increase serum Brain-Derived Neurothrophic Factor BDNF levels. Tianeptine is a safe medication that acts on the glutamatergic system and has an antidepressant effect. The present study aimed at assessing the efficacy and tolerability of tianeptine as an adjunctive treatment for bipolar depression. We performed an enriched maintenance multi-center double-blind randomized controlled trial of tianeptine 37•5mg/day. Participants (n = 161) had a Montgomery Asberg Depression Rating Score ≥12 at trial entry. After eight weeks of open-label tianeptine treatment, those who responded to tianeptine were randomized to adjunctive tianeptine or placebo in addition to usual treatment. Participants were recruited from public health services and through advertisement. Time to any intervention was the primary endpoint of the study. Changes in mood symptoms, functioning, biological rhythms, quality of life, rates of mania switch and serum BDNF assessments were considered as secondary outcomes. There was a robust decrease in depressive symptoms along with improvements in functioning, quality of life and biological rhythms scores during the eight-week open-label tianeptine treatment phase. During the subsequent 24-week double-blind controlled phase, there was no difference regarding the primary outcome: time to intervention. In addition, there were no significant differences between groups in mood symptoms, functioning and BDNF levels. Tianeptine was well tolerated and not associated with mania switch as compared to placebo. These findings suggest that tianeptine is a safe medication and may be effective in the treatment of acute bipolar depression. However, tianeptine did not show beneficial effects in the maintenance phase. This is the first long-term randomized, double-blind maintenance trial of antidepressant augmentation in bipolar disorder.
68

ENVOLVIMENTO DO SISTEMA DOPAMINÉRGICO NA AÇÃO DO TIPO ANTIDEPRESSIVA DO FENILSELENOMETIL EM CAMUNDONGOS FÊMEAS / ROLE OF DOPAMINERGIC SYSTEM ON THE ANTIDEPRESSANT-LIKE ACTION OF METHYL PHENYL SELENIDE IN FEMALE MICE

Oliveira, Carla Elena Sartori 05 August 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Depression affects millions of people of different ages, races, religions and income at some period of their lives. The etiology of most mood disorders, although not fully understood, has come into sharper focus in the recent past. This might also be of relevance in psychiatry as a poor treatment response often results from giving every patient the same treatment. Selenium-containing molecules show promising pharmacological properties. The antidepressant-like action of methyl phenyl selenide (CH3SePh) in the mouse forced swimming test (FST) and the tail suspension test (TST), models predictive of depressant activity, were investigated in this study. Moreover, the involvement of dopaminergic system in the antidepressant-like action of CH3SePh was studied. The behavioral results showed that CH3SePh significantly reduced the immobility time in the FST (25 and 50 mg/kg, intragastrically; i.g.) and the TST (50 mg/kg, i.g.), without accompanying changes in ambulation when assessed in the open-field test (OFT). The anti-immobility effect of CH3SePh (50 mg/kg, intragastrically; i.g.) in the FST was prevented by pretreatment of mice with haloperidol (0.2 mg/kg, i.p., a dopamine D2 receptor antagonist), SCH 23390 (R-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol) (0.05 mg/kg, s.c., a dopamine D1 receptor antagonist) and sulpiride (50 mg/kg, i.p., a dopamine D2 and D3 antagonist). These results suggest that CH3SePh produced an antidepressant-like action in the mouse FST and TST. The antidepressant-like action of CH3SePh, a simple selenium-containing molecule, seems most likely to be mediated through an interaction with the dopaminergic system. / A depressão é uma doença altamente incapacitante que atinge milhões de pessoas ao redor do mundo. Os tratamentos disponíveis para este transtorno embora eficazes apresentam efeitos adversos e altos índices de não responsividade ao tratamento. Moléculas orgânicas que contem selênio apresentam promissoras propriedades farmacológicas. Neste estudo, a ação do tipo antidepressiva do fenilseleniometil (CH3SePh) em camundongos fêmeas foi investigada utilizando-se o teste do nado forçado (TNF) e o teste de suspensão da cauda (TSC), que são modelos preditivos de atividade depressiva. Além disso, o envolvimento do sistema dopaminérgico na ação do tipo antidepressiva do CH3SePh foi estudado. Os resultados comportamentais demonstraram que o CH3SePh (25 e 50 mg/kg, administrado pela via intragastrica; i.g.) reduziu significativamente o tempo de imobilidade no TNF e no TSC (50 mg/kg, i.g.), sem alterar a locomoção quando analisados no teste do campo aberto (TCA). O efeito anti-imobilidade do CH3SePh (50 mg/kg, i.g.) no TNF foi prevenido pelo pré-tratamento dos camundongos com haloperidol (0.2 mg/kg, administrado pela via intraperitoneal, i.p., antagonista dos receptores dopaminérgicos D2), SCH 23390 (R-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol) (0.05 mg/kg, s.c., antagonista dos receptores dopaminérgicos D1) e sulpiride (50 mg/kg, i.p antagonista dos receptores dopaminérgicos D2 e D3). Estes resultados sugerem que o CH3SePh produziu uma ação do tipo antidepressiva no TNF e TSC em camundongos, dois modelos bem aceitos para triagem de novas drogas com potencial antidepressivo. Portanto, a ação do tipo antidepressiva do CH3SePh, uma molécula orgânica de selênio e de síntese simples, parece estar sendo mediada por uma interação com o sistema dopaminérgico.
69

Tianeptina e neuroprogressão no transtorno bipolar

Kapczinski, Natalia Soncini January 2016 (has links)
O curso longitudinal do transtorno bipolar é altamente variável, mas um subconjunto de pacientes parece apresentar uma evolução progressiva associada a alterações cerebrais e comprometimento funcional. Em nosso primeiro artigo, discutimos a teoria da neuroprogressão no transtorno bipolar. Este conceito considera a resposta ao estresse que ocorre nos episódios de humor e déficits no funcionamento e cognição, bem como alterações neuroanatômicas nos estágios tardios da doença. Discutimos também refratariedade ao tratamento que pode ocorrer em alguns casos de transtorno bipolar. Foi executada uma busca na base de dados PubMed para artigos publicados em qualquer idioma até 04 de junho de 2016. Foram encontrados 315 resumos e 87 estudos foram incluídos em nossa revisão. Somos da opinião de que o uso de estratégias farmacológicas específicas e remediação funcional pode ser potencialmente útil em pacientes bipolares em estágios tardios. Novas abordagens analíticas que utilizam dados multimodais têm o potencial para ajudar na identificação de assinaturas de subgrupos de pacientes que irão desenvolver um curso neuroprogressivo. Com base em nossa hipótese de neuroprogressão, decidimos realizar um ensaio clínico randomizado com o antidepressivo tianeptina como tratamento adjuvante para o transtorno bipolar, a fim de melhorar o comprometimento funcional, desfechos clínicos e aumentar os níveis do Brain-Derived Neurothrofic Factor (BDNF). Tianeptina é um fármaco seguro, que atua sobre o sistema glutamatérgico e tem um efeito antidepressivo. Esse estudo teve como objetivo avaliar a eficácia e tolerabilidade da tianeptina como tratamento adjuvante para a depressão bipolar. Foi realizado um ensaio clínico duplo-cego randomizado de manutenção controlado por placebo com tianeptina 37,5 mg/dia. Os participantes (n = 161) tinham uma pontuação na Montgomery Asberg Depression Rating ≥12 no início do ensaio. Após oito semanas de tratamento com tianeptina na fase aberta, aqueles que responderam a tianeptina foram randomizados para o placebo ou tianeptina adjuvante. Os participantes foram recrutados na rede pública de saúde. Tempo para qualquer intervenção foi o desfecho primário do estudo. Mudanças nos sintomas de humor, funcionamento, ritmos biológicos, qualidade de vida, taxas de virada maníaca e níveis séricos de BDNF foram considerados como desfechos secundários. Houve uma diminuição importante nos sintomas depressivos, assim como melhoras no funcionamento, qualidade de vida e pontuações no ritmo biológico durante a fase aberta de tratamento com tianeptina por oito semanas. Durante as 24 semanas do ensaio duplo-cego randomizado e controlado por placebo, não houve diferença em relação ao desfecho primário: tempo para qualquer intervenção. Além disso, não houve diferenças significativas entre os grupos em relação aos sintomas de humor, funcionamento e níveis de BDNF. Tianeptina foi bem tolerada e não foi associada a virada maníaca em comparação com o placebo. Estes achados sugerem que tianeptina é um medicamento seguro e pode ser eficaz no tratamento da depressão bipolar aguda. No entanto, tianeptina não mostrou efeitos benéficos na fase de manutenção. Este é o primeiro ensaio clínico duplo-cego randomizado de manutenção e de longo prazo com antidepressivo no transtorno bipolar. / The longitudinal course of bipolar disorder is highly variable, and a subset of patients seems to present a progressive course associated with brain changes and functional impairment. In our first article, we discussed the theory of neuroprogression in bipolar disorder. This concept considers the systemic stress response that occurs within mood episodes and late-stage deficits in functioning and cognition as well as neuroanatomic changes. We also discuss treatment refractoriness that may take place in some cases of bipolar disorder. We searched PubMed for articles published in any language up to June 4th, 2016. We found 315 abstracts and included 87 studies in our review. We are of the opinion that the use of specific pharmacological strategies and functional remediation may be potentially useful in bipolar patients at late-stages. New analytic approaches using multimodal data hold the potential to help in identifying signatures of subgroups of patients who will develop a neuroprogressive course. Based on our hypothesis of neuroprogression, we decided to perform a randomized clinical trial with tianeptine as adjunctive treatment for bipolar disorder in order to improve functional impairment and increase serum Brain-Derived Neurothrophic Factor BDNF levels. Tianeptine is a safe medication that acts on the glutamatergic system and has an antidepressant effect. The present study aimed at assessing the efficacy and tolerability of tianeptine as an adjunctive treatment for bipolar depression. We performed an enriched maintenance multi-center double-blind randomized controlled trial of tianeptine 37•5mg/day. Participants (n = 161) had a Montgomery Asberg Depression Rating Score ≥12 at trial entry. After eight weeks of open-label tianeptine treatment, those who responded to tianeptine were randomized to adjunctive tianeptine or placebo in addition to usual treatment. Participants were recruited from public health services and through advertisement. Time to any intervention was the primary endpoint of the study. Changes in mood symptoms, functioning, biological rhythms, quality of life, rates of mania switch and serum BDNF assessments were considered as secondary outcomes. There was a robust decrease in depressive symptoms along with improvements in functioning, quality of life and biological rhythms scores during the eight-week open-label tianeptine treatment phase. During the subsequent 24-week double-blind controlled phase, there was no difference regarding the primary outcome: time to intervention. In addition, there were no significant differences between groups in mood symptoms, functioning and BDNF levels. Tianeptine was well tolerated and not associated with mania switch as compared to placebo. These findings suggest that tianeptine is a safe medication and may be effective in the treatment of acute bipolar depression. However, tianeptine did not show beneficial effects in the maintenance phase. This is the first long-term randomized, double-blind maintenance trial of antidepressant augmentation in bipolar disorder.
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Obtenção de frações de valepotriatos através de fluido supercrítico e triagem psicofarmacológica de valeriana glechomifolia Meyer

Salles, Luisa de Andrade January 2010 (has links)
Espécies do gênero Valeriana são tradicionalmente utilizadas para tratar ansiedade, irritabilidade e desordens de sono. A Organização Mundial da Saúde indica o uso de preparações farmacêuticas como alternativa aos benzodiazepínicos para tratamento da ansiedade e insônia. Entre as substâncias ativas presentes no gênero Valeriana destacam-se os óleos voláteis, valepotriatos, flavonóides e lignanas. Entretanto, estudos farmacológicos com produtos isolados são escassos. Espécies nativas de Valeriana, que ocorrem no Rio Grande do Sul, têm sido estudadas em relação a sua composição química, sendo a espécie Valeriana glechomifolia a que possui maior teor de valepotriatos. Neste estudo, diferentes métodos de extração de valepotriatos foram comparados e extratos enriquecidos em valepotriatos foram testados em modelos animais de sedação, ansiedade e depressão. Valepotriatos isolados foram submetidos a ensaios de ligação a receptores benzodiazepínico e serotonérgico (5HT1A) e ensaios de atividade da enzima Na+K+ATPase. A extração por fluido supercrítico com dióxido de carbono (SCCO2) foi realizada em temperatura constante de 40 oC e pressões variáveis (90, 120, 150 e 200 bar) e demonstrou maior teor de valepotriatos que os métodos de extração por maceração em ultrassom e maceração Entre as diferentes pressões de extração utilizadas no método de SCCO2, o maior teor de valepotriatos foi apresentado pela fração obtida na pressão de 90 bar. Todos os extratos mostraram o mesmo perfil qualitativo de valepotriatos. Flavonóides também foram obtidos através de maceração por ultrassom em metanol. A dose letal mediana dos valepotriatos obtidos por maceração por ultrassom foi de 42±3 mg/kg, i.p. Esta mesma solução extrativa, na dose de 10 mg/kg, v.o. (gavage), foi inefetiva no labirinto em cruz elevado e tempo de sono barbitúrico, sugerindo a ausência de propriedades ansiolíticas e hipnótico-sedativas. Resultados similares foram obtidos com a solução extrativa enriquecida em flavonóides. Valtrato, acevaltrato, 1-b-acevaltrato, diavaltrato e o flavonóide codificado como B6 não apresentaram ligação ao sítio benzodiazepínico do complexo receptor GABAA, nem ao receptor serotonérgico (5HT1A) viii na faixa de concentração de 1-100 μM. Os valepotriatos inibiram a atividade da enzima Na+K+-ATPase na faixa de concentração micromolar. A fração de valepotriatos obtida por SCCO2 (10 mg/kg, gavage) foi efetiva no teste da natação forçada, sem interferir na atividade locomotora espontânea, sugerindo uma atividade do tipo antidepressiva. Em conclusão, a extração por fluido supercrítico com dióxido de carbono mostrou-se eficiente para a obtenção de frações enriquecidas em valepotriatos e estas substâncias representam uma nova classe química com atividade inibitória não seletiva da enzima Na+K+ATPase, e com atividade do tipo antidepressiva. / Species of the genus Valeriana are traditionally used to treat anxiety, irritability and sleep disorders. The World Health Organization indicates pharmaceutical preparations of V. officinalis as an alternative to benzodiazepine drugs for treating anxiety and insomnia. Volatile oil, valepotriates, flavonoids and lignan have been suggested as active substances of the Valeriana genus. However pharmacological studies on isolated compounds are scarce. Species of Valeriana native to Rio Grande do Sul have been studied regarding their chemical composition being Valeriana glechomifolia the species with highest valepotriate’ contents. In this study different methods of extraction of valepotriates from aerial parts of V. glechomifolia were compared, and valepotriate’ enriched extracts were tested in mice models of sedation, anxiety and depression. Isolated valepotriates were submitted to binding to benzodiazepine and 5HT1A receptors, and assayed for the Na+K+ATPase inhibitory activity. The extraction by supercritical carbon dioxide (SCCO2) was carried out at 40 oC under 90, 120, 150 or 200 bar affording higher valepotriates contents than maceration with dichloromethane and ultrasound. The highest valepotriates yielding was obtained with SCCO2 (40 oC , 90 bar). All extracts presented the same qualitative valepotriate’ profile. Flavonoids were also obtained from methanol extracts. The median lethal dose of valepotriates obtained by maceration was determined as 42±3 mg/kg, i.p. This valepotriate’ enriched extract (10 mg/kg, p.o., gavage) was ineffective in the elevated plus maze and barbiturate sleeping time tests suggesting that it does not present anxiolitic or hypnotic-sedative properties. Similar results were obtained with flavonoids’ enriched extract. Valtrate, acevaltrate, 1-b-acevaltrate, diavaltrate and the flavonoid named B6 did not bind to benzodiazepine site of receptor GABAA complex neither to serotonergic receptor (5HT1A) at 1-100 μM. The valepotriates inhibited the Na+K+ATPase activity at micromolar concentration range. The valepotriates fraction obtained by SCCO2 (10 mg/kg, gavage) was effective in the forced swimming test without interfering with the spontaneous locomotor activity suggesting that it presents an antidepressant-like activity. In conclusion the extraction by supercritical carbon dioxide is valuable to obtain valepotriates enriched fractions; and valepotriates seem to represent new chemical entities with no selective inhibitory activity of Na+K+ATPase, as well as with antidepressant-like activity.

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