RESUMO
There is a lack of information concerning the molecular events underlying the depressive-like effect of an intracerebroventricular injection of streptozotocin (ICV-STZ) in mice. The elevated activity of the tryptophan-degrading enzyme indoleamine-2,3-dioxygenase (IDO) has been proposed to mediate depression in inflammatory disorders. In the present study, we reported that ICV-STZ activates IDO in the hippocampus of mice and culminates in depressive-like behaviors, as measured by the increased duration of immobility in the tail suspension test and decreased sucrose intake in the sucrose preference test. The blockade of IDO activation by the IDO inhibitor 1-methyltryptophan (1-MT) prevents the development of depressive-like behaviors and attenuates STZ-induced up-regulation of proinflammatory cytokines in the hippocampus. 1-MT abrogates kynurenine production and normalizes brain-derived neurotrophic factor (BDNF) and the kynurenine/tryptophan ratio, but does not protect the biomarkers of the serotonin (5-HT) system in the hippocampus of STZ-injected mice. These results implicate IDO as a critical molecular mediator of STZ-induced depressive-like behavior, likely through activation of the kynurenine pathway and subsequent reduction of BDNF levels. Impairment of the 5-HT system may reflect the inflammatory response induced by STZ and also contributes to observed depression symptoms. The present study not only provides evidence that IDO plays a critical role in mediating inflammation-induced depression but also supports the notion that neuroinflammation and the kynurenine pathway are important targets for novel therapeutic drugs for depression. In addition, this study provides new insights on the neurobiological mechanisms underlying ICV-STZ and indicates that this model could be employed in preclinical research of depression.
Assuntos
Comportamento Animal/efeitos dos fármacos , Depressão/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Estreptozocina/farmacologia , Animais , Depressão/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Cinurenina/efeitos dos fármacos , Cinurenina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Serotonina/metabolismoRESUMO
Emerging evidence indicates that the activation of indoleamine-2,3-dioxygenase (IDO), a first and rate-limiting enzyme in the kynurenine (KYN) pathway, is involved in amyloid-beta (Aß1-42)-neurotoxicity and Alzheimer's disease (AD) pathogenesis. Physical exercise has been considered an effective intervention in AD, attenuating or limiting their progression. Nevertheless, the neurobiological mechanisms underlying the neuroprotective effects of exercise have not yet been fully elucidated. In present study, we investigated the protective effect of an 8-week swimming training (ST) exercise on cognitive and non-cognitive functions and its role in modulating biomarkers of KYN pathway, before an intracerebroventricular (i.c.v.) injection of Aß1-42 (400pmol/animal; 3µl/site) peptide in mice. Our results demonstrated that ST was effective in preventing the following behavioural disturbances caused by Aß1-42 injection: memory impairment in the object recognition test and depressive/anxiety-like behaviour in the tail suspension test and elevated plus-maze test, respectively. ST abrogated the neuroinflammatory response and neurotrophic deficiency in the prefrontal cortex and hippocampus induced by Aß1-42. Also, Aß1-42 increased IDO activity, KYN and tryptophan (TRP) levels and KYN:TRP ratio in the prefrontal cortex and hippocampus - alterations that were blocked by ST. It can be concluded that ST prevented behavioural and neurobiological deficits induced by Aß1-42, and suggest that these neuroprotective effects are likely to involve the inhibition of inflammation/IDO activation and up-regulation of neurotrophic factors in brain of mice. Thus, it is possible that physical exercise can be used as a non-pharmacological approach to alleviates both cognitive and non-cognitive symptoms of AD.
Assuntos
Peptídeos beta-Amiloides/farmacologia , Comportamento Animal/efeitos dos fármacos , Citocinas/metabolismo , NF-kappa B/metabolismo , Fragmentos de Peptídeos/farmacologia , Natação , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/administração & dosagem , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/metabolismo , Camundongos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/administração & dosagem , Condicionamento Físico Animal , Natação/fisiologiaRESUMO
Chrysin is a flavonoid which is found in bee propolis, honey and various plants. Antidepressant-like effect of chrysin in chronically stressed mice was previously demonstrated by our group. Conversely, neurochemical factors associated with this effect require further investigations. Thus, we investigated the possible involvement of pro-inflammatory cytokines, kynurenine pathway (KP), 5-hydroxytryptamine (5-HT) metabolism and caspases activities in the effect of chrysin in mice exposed to unpredictable chronic stress (UCS). UCS applied for 28 days induced a depressive-like behavior, characterized by decrease in the time of grooming in the splash test and by increase in the immobility time in the tail suspension test. Oral treatment with chrysin (5 or 20mg/kg, 28 days), similarly to fluoxetine (10mg/kg, positive control), culminated in the prevention of these alterations. UCS elevated plasma levels of corticotropin-releasing hormone and adrenocorticotropic hormone, as well the tumor necrosis factor-α, interleukin-1ß, interleukin-6 and kynurenine levels in the prefrontal cortex (PFC) and hippocampus (HP). UCS induced the decrease in the 5-HT levels in the HP and the increase in the indoleamine-2,3-dioxygenase, caspase 3 and 9 activities in the PFC and HP. Treatment with chrysin, similarly to fluoxetine, promoted the attenuation of these alterations occasioned by UCS. These results corroborated with the antidepressant potential of chrysin in the treatment of psychiatric diseases. Furthermore, this work indicated the association of pro-inflammatory cytokines synthesis, KP, 5-HT metabolism and caspases activities with the action exercised by chrysin in mice exposed to UCS.
Assuntos
Antidepressivos/farmacologia , Flavonoides/farmacologia , Neuroquímica , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Hormônio Adrenocorticotrópico/sangue , Animais , Antidepressivos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Caspases/metabolismo , Citocinas/metabolismo , Feminino , Flavonoides/uso terapêutico , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Cinurenina/metabolismo , Camundongos , Receptores de Hormônio Liberador da Corticotropina/sangue , Serotonina/metabolismo , Triptofano/metabolismoRESUMO
Depression is one of the most common mental disorders and a primary cause of disability. To better treat patients suffering this illness, elucidation of the underlying psychopathological and neurobiological mechanisms is urgently needed. Based on the above-mentioned evidence, we sought to investigate the effects of neuropeptide Y (NPY) treatment in tricyclic antidepressant treatment-resistant depression induced by adrenocorticotropic hormone (ACTH) administration. Mice were treated with NPY (5.84, 11.7 or 23.4mmol/µl) intracerebroventricularly (i.c.v.) for one or five days. The levels of serum corticosterone, tryptophan (TRP), kynurenine (KYN), serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and indoleamine 2,3-dioxygenase (IDO) activity in the hippocampus were analyzed. The behavioral parameters (depressive-like and locomotor activity) were also verified. This study demonstrated that ACTH administration increased serum corticosterone levels, KYN, 5-HIAA levels, IDO activity (hippocampus), immobility in the forced swimming test (FST) and the latency to feed in the novelty suppressed feeding test (NSFT). In addition, ACTH administration decreased the BDNF and NGF levels in the hippocampus of mice. NPY treatment was effective in preventing these hormonal, neurochemical and behavioral alterations. It is suggested that the main target of NPY is the modulation of corticosterone and neuronal plasticity protein levels, which may be closely linked with pharmacological action in a model of tricyclic antidepressant treatment-resistant depression. Thus, this study demonstrated a protective effect of NPY on the alterations induced by ACTH administration in mice, indicating that it could be useful as a therapy for the treatment of tricyclic antidepressant treatment-resistant depression.
Assuntos
Hormônio Adrenocorticotrópico , Antidepressivos Tricíclicos/uso terapêutico , Transtorno Depressivo/induzido quimicamente , Transtorno Depressivo/tratamento farmacológico , Resistência a Medicamentos/efeitos dos fármacos , Neuropeptídeo Y/farmacologia , Animais , Corticosterona/sangue , Transtorno Depressivo/sangue , Modelos Animais de Doenças , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Ácido Hidroxi-Indolacético/sangue , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neuropeptídeo Y/administração & dosagem , Natação/fisiologiaRESUMO
In this study, the effect of Chrysin (5,7-dihydroxyflavone), an important member of the flavonoid family, on memory impairment, oxidative stress and BDNF reduction generated by aging in mice were investigated. Young and aged mice were treated daily per 60days with Chrysin (1 and 10mg/kg; per oral, p.o.) or veichle (10ml/kg; p.o.). Mice were trained and tested in Morris Water Maze task. After the behavioural test, the levels of reactive species (RS), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), as well as the activity of Na(+), K(+)-ATPase and the levels of brain-derived neurotrophic factor (BDNF) were determined in the prefrontal cortex (PFC) and hippocampus (HC) of mice. Results demonstrated that the age-related memory decline was partially protected by Chrysin at a dose of 1mg/kg, and normalized at the dose of 10mg/kg (p<0.001). Treatment with Chrysin significantly attenuated the increase of RS levels and the inhibition of SOD, CAT and GPx activities of aged mice. Inhibition of Na(+), K(+)-ATPase activity in PFC and HP of aged mice was also attenuated by Chrysin treatment. Moreover, Chrysin marked mitigated the decrease of BDNF levels in the PFC and HC of aged mice. These results demonstrated that flavonoid Chrysin, an antioxidant compound, was able to prevent age-associated memory probably by their free radical scavenger action and modulation of BDNF production. Thus, this study indicates that Chrysin may represent a new pharmacological approach to alleviate the age-related declines during normal age, acting as an anti-aging agent.
Assuntos
Envelhecimento/psicologia , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Transtornos Cognitivos/prevenção & controle , Flavonoides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Biomarcadores/metabolismo , Encéfalo/enzimologia , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Masculino , Camundongos , Distribuição Aleatória , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
The administration of hesperidin elicits an antidepressant-like effect in mice by a mechanism dependent on an interaction with the L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway, whose stimulation is associated with the activation of potassium (K(+)) channels. Thus, this study investigated the involvement of different types of K(+) channels in the antidepressant-like effect of hesperidin in the mice tail suspension test (TST). The intracerebroventricular administration of tetraethylammonium (TEA, a nonspecific blocker of K(+) channels), glibenclamide (an ATP-sensitive K(+) channel blocker), charybdotoxin (a large- and intermediate-conductance calcium-activated K(+) channel blocker) or apamin (a small-conductance calcium-activated K(+) channel blocker) combined with a subeffective dose of hesperidin (0.01 mg/kg, intraperitoneally [i.p.]) was able to produce a synergistic antidepressant-like effect in the mice TST. Moreover, the antidepressant-like effect elicited by an effective dose of hesperidin (0.3 mg/kg, i.p.) in TST was abolished by the treatment of mice with pharmacological compounds K(+) channel openers (cromakalim and minoxidil). Results showed that the antidepressant-like effect of hesperidin in TST may involve, at least in part, the modulation of neuronal excitability through inhibition of K(+) channels and may act through a mechanism dependent on the inhibition of L-arginine-NO pathway.
Assuntos
Antidepressivos/farmacologia , Hesperidina/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio/fisiologia , Animais , Apamina/administração & dosagem , Arginina/farmacologia , Charibdotoxina/administração & dosagem , Sinergismo Farmacológico , Glibureto/administração & dosagem , Hesperidina/administração & dosagem , Elevação dos Membros Posteriores , Masculino , Camundongos , Bloqueadores dos Canais de Potássio/administração & dosagem , Bloqueadores dos Canais de Potássio/uso terapêutico , Canais de Potássio/efeitos dos fármacos , Tetraetilamônio/administração & dosagemRESUMO
CONTEXT: The organoselenium compounds have been described to demonstrate several biological activities, including pain management. OBJECTIVE: This study investigated the antinociceptive, hyperalgesic, and toxic effects of oral administration of bis(4-methylbenzoyl) diselenide (BMD) in mice. MATERIALS AND METHODS: The antinociceptive and anti-hyperalgesic effects of BMD (1, 5, 10, 25, and 50 mg/kg, p.o.) were evaluated using models of nociception: formalin, capsaicin, bradykinin (BK), cinnamaldehyde, phorbol myristate acetate (PMA), 8-bromo-cAM, and glutamate-induced nociception; and mechanical hyperalgesia induced by carrageenan (Cg) or complete Freund's adjuvant (CFA). The acute toxicity was evaluated by biochemical markers for hepatic and renal damages. RESULTS: BMD significantly inhibited the licking time of the injected paw in the early and late phases of a formalin test with ED50 values of 14.2 and 10.8 mg/kg, respectively. This compound reduced nociception produced by capsaicin (ED50 of 32.5 mg/kg), BK (ED50 of 24.6 mg/kg), glutamate (ED50 of 28.7 mg/kg), cinnamaldehyde (ED50 of 18.9 mg/kg), PMA (ED50 of 9.6 mg/kg), and 8-bromo-cAMP (ED50 of 24.8 mg/kg). In the glutamate test, the pretreatment with nitric oxide (NO) precursor, L-arginine, reversed antinociception caused by BMD or N(ω)-nitro-L-arginine (L-NOARG), but the effect of BMD was not abolished by naloxone. Mechanical hyperalgesia induced by Cg and CFA was attenuated by BMD, 70 ± 4% and 65 ± 4%, respectively. Furthermore, a single oral dose of BMD did not change plasma aspartate (AST) and alanine aminotransferase (ALT) activities or urea and creatinine levels. CONCLUSION: BMD demonstrated as a promising compound because of the antinociceptive and anti-hyperalgesic properties in mice.
Assuntos
Analgésicos/uso terapêutico , Hiperalgesia/tratamento farmacológico , Compostos Organosselênicos/uso terapêutico , Substâncias Protetoras/uso terapêutico , Analgésicos/farmacologia , Animais , Relação Dose-Resposta a Droga , Hiperalgesia/patologia , Masculino , Camundongos , Compostos Organosselênicos/farmacologia , Medição da Dor/efeitos dos fármacos , Medição da Dor/métodos , Substâncias Protetoras/farmacologiaRESUMO
AIMS: The study investigated the antidepressant-like effect and acute toxicity of 4-phenyl-1-(phenylselanylmethyl)-1,2,3-triazole (Se-TZ), an organoselenium-containing heterocycle compound in mice. MAIN METHODS: The antidepressant-like effect of Se-TZ (1-50mg/kg) and its mechanism of action, was analyzed in the tail suspension test (TST) in male C57BL/6J mice. Additionally, the levels of the monoamines and their metabolites in cerebral cortex and hippocampus were analyzed by high-performance liquid chromatography. To investigate the potential acute toxicity caused by Se-TZ, the mice received a single oral dose of Se-TZ (1-50mg/kg), and after 72h were performed the assays. KEY FINDINGS: The Se-TZ (5-50mg/kg) significantly reduced immobility time in TST without altering locomotor and exploratory activities. The antidepressant-like effect of Se-TZ (25mg/kg) in the TST was prevented by pre-treatment of mice with SCH23390, sulpiride and methysergide, but not with prazosin, yohimbine and propranolol. Se-TZ, increased monoamine neurotransmitters dopamine and serotonin levels in the cerebral cortex and hippocampus, whereas norepinephrine turnover was not changed. This study also demonstrated that the Se-TZ, did not cause the acute toxicity in biochemical markers hepatic and renal investigated. The results evidenced that exposure to Se-TZ caused a significant increase in the catalase (CAT) activity in the cerebral cortex and hippocampus, however the glutathione S-transferase (GST) activity increased only in the cerebral cortex. SIGNIFICANCE: These results suggest that Se-TZ demonstrated antidepressant-like effect, mediated via the central dopaminergic and serotoninergic neurotransmitter systems which may be of interest as a therapeutic agent for the treatment of depressive disorders.