RESUMO
AIMS: Central melanocortin 4 receptor (MC4R) has been reported to induce anhedonia via eliciting dysfunction of excitatory synapses. It is evident that metabolic signals are closely related to chronic stress-induced depression. Here, we investigated that a neural circuit is involved in melanocortin signaling contributing to susceptibility to stress. METHODS: Chronic social defeat stress (CSDS) was used to develop depressive-like behavior. Electrophysiologic and chemogenetic approaches were performed to evaluate the role of paraventricular thalamus (PVT) glutamatergic to nucleus accumbens shell (NAcsh) circuit in stress susceptibility. Pharmacological and genetic manipulations were applied to investigate the molecular mechanisms of melanocortin signaling in the circuit. RESULTS: CSDS increases the excitatory neurotransmission in NAcsh through MC4R signaling. The enhanced excitatory synaptic input in NAcsh is projected from PVT glutamatergic neurons. Moreover, chemogenetic manipulation of PVTGlu -NAcsh projection mediates the susceptibility to stress, which is dependent on MC4R signaling. Overall, these results reveal that the strengthened excitatory neurotransmission in NAcsh originates from PVT glutamatergic neurons, facilitating the susceptibility to stress through melanocortin signaling. CONCLUSIONS: Our results make a strong case for harnessing a thalamic circuit to reorganize excitatory synaptic transmission in relieving stress susceptibility and provide insights gained on metabolic underpinnings of protection against stress-induced depressive-like behavior.
Assuntos
Núcleo Accumbens , Receptor Tipo 4 de Melanocortina , Núcleo Accumbens/metabolismo , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo , Tálamo , Neurônios/metabolismo , Transmissão SinápticaRESUMO
OBJECTIVE: In this prospective cohort study, we aimed to evaluate the association between dietary habits and the risk of developing hepatocellular carcinoma (HCC) in hepatitis B surface antigen (HBsAg)-positive carriers in Qidong, an hepatitis B virus (HBV)-epidemic area in China. METHODS: A total of 3199 HBsAg carriers aged 30-70 years in a prospective cohort in Qidong, China from 2007 to 2011 were included in the study. At baseline, all participants self-reported their dietary habits in a questionnaire interview. A follow-up check-up was performed every 6 months to identify HCC cases until November 2017. Cox's regression analysis and an interaction analysis were performed to estimate the relative risks of HCC in terms of baseline diet. RESULTS: Among 3199 HBsAg-positive participants, 270 developed HCC (143.86/100 000 person-years [PYs]). Compared with participants who rarely consume garlic, the risk of HCC in those who consumed it ≥ once per week decreased along with the increase in frequency (HR = 1.00, 0.90 and 0.62 in those who consumed it rarely vs those who consumed it 1-6 times per week and ≥ 7 times per week, respectively). This study found a synergistic effect between garlic and tea consumption on the risk of HCC (P = 0.039 for a multiplicative interaction). CONCLUSIONS: HBsAg carriers should improve their diet. Regular consumption of garlic and tea drinking may reduce the HCC incidence in HBsAg carriers.
Assuntos
Carcinoma Hepatocelular , Dieta , Antígenos de Superfície da Hepatite B/sangue , Hepatite B Crônica , Neoplasias Hepáticas , Carcinoma Hepatocelular/epidemiologia , China , Alho , Vírus da Hepatite B , Hepatite B Crônica/epidemiologia , Humanos , Neoplasias Hepáticas/epidemiologia , Estudos Prospectivos , Fatores de Risco , CháRESUMO
Sulforaphane is a redox-active natural product present in cruciferous vegetables like broccoli. Broccoli sprout-derived products are promising agents for the prevention of oxidative stress-related diseases, but some have long been suspected of thyroidal toxicity. Recent findings also raise the possibility that long-term exposure to sulforaphane, or to other natural substances or drugs that modulate the activity of the transcription factor Nrf2 (NFE2-related factor 2) may lead to thyroid dysfunction or thyroid autoimmune disease, questioning the safety of trials with sulforaphane-containing products. Previous studies addressing possible effects of sulforaphane-related compounds from natural product extracts on the thyroid were quite short and/or inconsistent. To investigate whether long-term exposure to a beverage enriched with sulforaphane and its precursor glucoraphanin may affect thyroid function, we analyzed biochemical measures of thyroid function and thyroid autoimmunity in 45 female participants in a randomized clinical trial at baseline and after 84 days of beverage administration. Serum levels of thyroid-stimulating hormone, free thyroxine and thyroglobulin were not affected by the treatment, and neither was the thyroid autoimmunity status of participants. These results provide evidence in favor of the safety of chemoprevention strategies that target the activation of Nrf2 to protect against environmental exposures and other oxidative stress-related pathologies.
Assuntos
Autoimunidade , Brassica/metabolismo , Sucos de Frutas e Vegetais/análise , Fator 2 Relacionado a NF-E2/metabolismo , Glândula Tireoide/metabolismo , Tri-Iodotironina/metabolismo , Adulto , Idoso , Brassica/química , Feminino , Humanos , Isotiocianatos/metabolismo , Masculino , Pessoa de Meia-Idade , Fator 2 Relacionado a NF-E2/genética , Preparações de Plantas/química , Preparações de Plantas/metabolismo , Estudos Retrospectivos , Sulfóxidos , Tireotropina/metabolismo , Adulto JovemRESUMO
In this review, we summarize the involvement of vitamin C in mental disorders by presenting available evidence on its pharmacological effects in animal models as well as in clinical studies. Vitamin C, especially its reduced form, has gained interest for its multiple functions in various tissues and organs, including central nervous system (CNS). Vitamin C protects the neuron against oxidative stress, alleviates inflammation, regulates the neurotransmission, affects neuronal development and controls epigenetic function. All of these processes are closely associated with psychopathology. In the past few decades, scientists have revealed that the deficiency of vitamin C may lead to motor deficit, cognitive impairment and aberrant behaviors, whereas supplement of vitamin C has a potential preventive and therapeutic effect on mental illness, such as major depressive disorder (MDD), schizophrenia, anxiety and Alzheimer's disease (AD). Although several studies support a possible role of vitamin C against mental disorders, more researches are essential to accelerate the knowledge and investigate the mechanism in this field.
Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Transtornos Mentais/prevenção & controle , Vitaminas/farmacologia , Animais , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/uso terapêutico , Sistema Nervoso Central/efeitos dos fármacos , Humanos , Transtornos Mentais/tratamento farmacológico , Vitaminas/administração & dosagem , Vitaminas/uso terapêuticoRESUMO
Methionine (Met) sulfoxide reductase A (MsrA) is a key endogenous antioxidative enzyme with longevity benefits in animals. Only very few approaches have been reported to enhance MsrA function. Recent reports have indicated that the antioxidant capability of MsrA may involve a Met oxidase activity that facilities the reaction of Met with reactive oxygen species (ROS). Herein, we used a homology modeling approach to search the substrates for the oxidase activity of MsrA. We found that dimethyl sulfide (DMS), a main metabolite that produced by marine algae, emerged as a good substrate for MsrA-catalytic antioxidation. MsrA bounds to DMS and promoted its antioxidant capacity via facilitating the reaction of DMS with ROS through a sulfonium intermediate at residues Cys72, Tyr103, and Glu115, followed by the release of dimethyl sulfoxide (DMSO). DMS reduced the antimycin A-induced ROS generation in cultured PC12 cells and alleviated oxidative stress. Supplement of DMS exhibited cytoprotection and extended longevity in both Caenorhabditis elegans and Drosophila. MsrA knockdown abolished the cytoprotective effect and the longevity benefits of DMS. Furthermore, we found that the level of physiologic DMS was at the low micromolar range in different tissues of mammals and its level decreased after aging. This study opened a new window to elucidate the biological role of DMS and other low-molecular sulfides in the cytoprotection and aging.
Assuntos
Biocatálise/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Drosophila melanogaster/fisiologia , Longevidade/fisiologia , Metionina Sulfóxido Redutases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Sulfetos/farmacologia , Aminoácidos/metabolismo , Animais , Antioxidantes/farmacologia , Sítios de Ligação , Caenorhabditis elegans/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Sequestradores de Radicais Livres/metabolismo , Técnicas de Silenciamento de Genes , Longevidade/efeitos dos fármacos , Modelos Biológicos , Células PC12 , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Polygonum multiflorum Thunb is a traditional Chinese medicine with anti-aging effect. 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG) is generally considered as the main active component in Polygonum multiflorum Thunb. However, the effect of TSG on memory in adult is unclear till now. AIM OF STUDY: 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG) is a polyphenols compound from Polygonum multiï¬orum Thunb. The present study aimed to evaluate the effect of chronic administration of TSG on hippocampal memory in normal mice. MATERIALS AND METHODS: Behavioral test, electrophysiology and golgi staining were used to evaluate the effect of TSG on hippocampus-dependent memory and synaptic plasticity. Western blotting was used to determine the expression of ERK1/2, CaMKII, and SIRT1. Real-time quantitative PCR was explored to measure miR-134. RESULTS: It was found that TSG enhanced hippocampus-dependent contextual fear memory and novel object recognition, facilitated hippocampal LTP and increased dendrite spine density in the CA1 region of hippocampus. TSG obviously promoted the phosphorylations of ERK1/2, CaMKII, CREB and the expression of BDNF in the hippocampus, with upregulation of silent information regulator 1 (SIRT1) and downregulation of miR-134. CONCLUSIONS: Chronic administration of TSG promotes hippocampal memory in normal mice, suggesting that supplementary of TSG might serve as an enhancement of memory.
Assuntos
Comportamento Animal/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glucosídeos/farmacologia , Hipocampo/efeitos dos fármacos , Memória/efeitos dos fármacos , MicroRNAs/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Nootrópicos/farmacologia , Sirtuína 1/metabolismo , Estilbenos/farmacologia , Animais , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/enzimologia , Ativação Enzimática , Medo/efeitos dos fármacos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Fosforilação , Reconhecimento Psicológico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fatores de TempoRESUMO
AIMS: Anxiety disorders are characterized by a deficient extinction of fear memory. Evidence is growing that leptin influences numerous neuronal functions. The aims of this study were to investigate the effects and the mechanism of leptin on fear extinction. METHODS AND RESULTS: Leptin (1 mg/kg, i.p) was applied to evaluate the anxiolytic effect in rat behavioral tests. Field potentials recording were used to investigate the changes in synaptic transmission in the thalamic-lateral amygadala (LA) pathway of rat. We found that leptin produced strong anxiolytic effects under basal condition and after acute stress. Systemic administration and intra-LA infusions of leptin facilitated extinction of conditioned fear responses. The antagonist of NMDA receptor, MK-801, blocked the effect of leptin on fear extinction completely. Furthermore, these effects of leptin on fear extinction were accompanied by a reversal of conditioning-induced synaptic potentiation in the LA. Leptin facilitated NMDA receptor-mediated synaptic transmission, and reversed amygdala long-term potentiation (LTP) in a dose-dependent manner in vitro, and this LTP depotentiation effect was mediated by NMDA receptor and MAPK signaling pathway. CONCLUSIONS: These results identify a key role of leptin in dampening fear conditioning-induced synaptic potentiation in the LA through NMDA receptor and indicate a new strategy for treating anxiety disorders.
Assuntos
Ansiolíticos/farmacologia , Ansiedade/tratamento farmacológico , Extinção Psicológica/efeitos dos fármacos , Medo/efeitos dos fármacos , Leptina/farmacologia , Animais , Ansiedade/fisiopatologia , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/fisiopatologia , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Maleato de Dizocilpina/farmacologia , Relação Dose-Resposta a Droga , Antagonistas de Aminoácidos Excitatórios/farmacologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/fisiologia , Camundongos Endogâmicos C57BL , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Distribuição Aleatória , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Proteínas Recombinantes/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Tálamo/efeitos dos fármacos , Tálamo/fisiopatologia , Técnicas de Cultura de TecidosRESUMO
Considerable evidence indicates that methionine sulfoxide (MetO) reductase A (MsrA) plays an important role in cytoprotection against oxidative stress and serves as a potential drug target. To screen for MsrA regulators, a rapid and specific assay to monitor MsrA activity is required. Most of current assays for MsrA activity are based on the reduction of radioactive substrates such as [3H]-N-acetyl-MetO or fluorescent derivatives such as dimethylaminoazo-benzenesulfonyl-MetO. However, these assays require extraction procedures and special instruments. Here, we developed a specific colorimetric microplate assay for testing MsrA activity quickly, which was based on the fact that MsrA can catalyze the reduction of methyl sulfoxides and simultaneously oxidize dithiothreitol (DTT), whose color can be produced by reacting with Ellman's reagent (dithio-bis-nitrobenzoic acid, DTNB). The corresponding absorbance change at 412nm was recorded with a microplate reader as the reaction proceeded. This method to monitor MsrA activity is easy to handle. Our findings may serve as a rapid method for the characterization of recombinant enzyme and for the screening of enzyme inhibitors, pharmacological activators, gene expression regulators and novel substrates.
Assuntos
Colorimetria/métodos , Oxirredutases/metabolismo , Animais , Ácido Ditionitrobenzoico , Ditiotreitol/metabolismo , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Estresse Oxidativo , Oxirredutases/antagonistas & inibidores , Oxirredutases/genética , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrofotometria , Especificidade por Substrato , Sulfóxidos/metabolismoRESUMO
In order to investigate the dynamic processes of mRNA levels of proenkephalin, proopiomelanocortin, prodynorphin, and opioid receptors (δ-, µ-, and κ-receptor) induced by electroacupuncture (EA) in the central nerve system, goats were stimulated by EA of 60 Hz for 0.5 h at a set of Baihui, Santai, Ergen, and Sanyangluo points. The pain threshold was measured using the method of potassium iontophoresis. The mRNA levels of the three opioid peptide precursors and three opioid receptors were determined with quantitative real-time PCR and the levels of Met-enkephalin with SABC immunohistochemistry at 0.5 h before and at 0, 2, 4, 6, 8, 12, and 24 h after EA. The results showed that the pain threshold correlated (P < 0.01) with Met-enkephalin immunoactivities in the measured nuclei and areas of goats. The analgesic aftereffect lasted for 12 h at least. The mRNA levels of the three opioid peptide precursors and three opioid receptors began to increase at 0 h, reached the peak during the time from 4 h to 6 h or at 12 h, and remained higher at 24 h after EA was discontinued. These results suggested that the initiation of gene expression of opioid peptides and the three receptors may be associated with EA-induced analgesic aftereffect.
RESUMO
Specialized bracts are thought to be important for the successful reproduction of some plants and are regarded as adaptations to diverse driving forces. However, few empirical studies have quantified the adaptive significance of bracts within a cost-benefit framework. We explored the adaptive significance of large and showy bracts for reproduction in Rheum nobile, a giant herb endemic to the high Himalayas. We examined whether the bracts enhance reproductive success during flowering and seed development. Bracts increased flower and fruit temperature on sunny days, greatly decreased the intensity of ultraviolet-B (UV-B) radiation reaching flowers and fruits, and prevented pollen grains being washed away by rain. Experiments indicated that high temperature could promote pollen germination, while pollen grains exposed to rain and UV-B radiation at ambient levels were seriously damaged. Furthermore, bract removal decreased the number of pollinators visiting flowers. When bracts were removed before or after flowering, fecundity and progeny quality were adversely affected, but seed predation by larvae of pollinators decreased. A cost-benefit analysis demonstrated that the cost of bracts, i.e., increased seed predation, is modest. Our results suggest that the bracts of R. nobile promote pollen germination, protect pollen grains from rain and intense UV-B radiation, enhance pollinator visitation during flowering, and facilitate the development of fertilized ovules during seed development. We conclude that multifunctional bracts of R. nobile are an effective adaptive strategy in alpine environments and might have been selected for because of abiotic environmental conditions as well as for enhancing pollination success.
Assuntos
Flores/fisiologia , Folhas de Planta/fisiologia , Pólen/fisiologia , Rheum/fisiologia , Sementes/crescimento & desenvolvimento , Adaptação Fisiológica , Animais , China , Flores/crescimento & desenvolvimento , Germinação , Polinização , Chuva , Reprodução/fisiologia , Temperatura , Raios UltravioletaRESUMO
OBJECTIVE: To study the traditional Chinese medicine (TCM) syndrome distribution in patients with hepatitis B virus (HBV) infection in Qidong region of Jiangsu Province, China. METHODS: A cross-sectional survey was performed. Subjects from Qidong of Jiangsu Province of China were screened among the locally enrolled residents by detecting hepatitis B surface antigen (HBsAg) from May 2007 to May 2011 and were assigned to HBsAg-negative cohort or HBsAg-positive cohort. Then, the subjects were diagnosed according to alanine aminotransferase, alpha-fetoprotein and B ultrasound. The syndrome of the subjects was determined using a TCM questionnaire consisting of signs and symptoms. RESULTS: A total of 5 908 subjects were enrolled in this survey, among whom, 4 718 were diagnosed with HbsAg infection (positive result of HbsAg detection) and 1 147 were negative. 143 subjects were excluded for not receiving the blood examination. The final diagnoses of the subjects were non-HBV infection (n=1128), HBV carrier (n=4019), chronic hepatitis B (n=225), posthepatitic cirrhosis (n=263) or liver cancer (n=111). The TCM syndrome differentiation results showed that there were differences in syndrome distribution between HBV-infected and non-HBV-infected patients. The main syndromes of the HBV-infected patients were qi deficiency, qi stagnation, blood stasis and dampness heat, related to the Zang of liver and spleen. The distribution principles of TCM syndrome among patients of HBV carrier, chronic hepatitis B and cirrhosis were similar. Moreover, with the progression of the patients' condition, the scores of syndromes increased, and the number of accompanying syndromes increased as well. The main syndromes of patients with liver cancer were blood stasis and excess heat, which was slightly different from that of the other HBV-infected patients. CONCLUSION: The TCM syndrome distribution in patients of HBV infection in Qidong region of Jiangsu Province shows regularity. The disorder is mainly due to qi stagnation and blood stasis and is also related to deficiency of healthy qi, especially deficiency of spleen qi.
Assuntos
Hepatite B/diagnóstico , Hepatite B/epidemiologia , Medicina Tradicional Chinesa , Adulto , China/epidemiologia , Estudos Transversais , Feminino , Antígenos de Superfície da Hepatite B/sangue , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/epidemiologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Astrocytes are implicated in information processing, signal transmission, and regulation of synaptic plasticity. Aquaporin-4 (AQP4) is the major water channel in adult brain and is primarily expressed in astrocytes. A growing body of evidence indicates that AQP4 is a potential molecular target for the regulation of astrocytic function. However, little is known about the role of AQP4 in synaptic plasticity in the amygdala. Therefore, we evaluated long-term potentiation (LTP) in the lateral amygdala (LA) and associative fear memory of AQP4 knockout (KO) and wild-type mice. We found that AQP4 deficiency impaired LTP in the thalamo-LA pathway and associative fear memory. Furthermore, AQP4 deficiency significantly downregulated glutamate transporter-1 (GLT-1) expression and selectively increased NMDA receptor (NMDAR)-mediated EPSCs in the LA. However, low concentration of NMDAR antagonist reversed the impairment of LTP in KO mice. Upregulating GLT-1 expression by chronic treatment with ceftriaxone also reversed the impairment of LTP and fear memory in KO mice. These findings imply a role for AQP4 in synaptic plasticity and associative fear memory in the amygdala by regulating GLT-1 expression.
Assuntos
Tonsila do Cerebelo/metabolismo , Tonsila do Cerebelo/fisiologia , Aquaporina 4/genética , Transportador 2 de Aminoácido Excitatório/biossíntese , Medo/psicologia , Memória/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Ceftriaxona/farmacologia , Regulação para Baixo/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciação de Longa Duração/fisiologia , Masculino , Camundongos , Camundongos Knockout , Vias Neurais/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , Tálamo/fisiologia , Regulação para Cima/efeitos dos fármacosAssuntos
Pontos de Acupuntura , Terapia por Acupuntura , Traumatismos do Tornozelo/terapia , Entorses e Distensões/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
Depression and related mood disorders are among the world's greatest public health problems. Previous studies have demonstrated that baicalein (Bai), one plant-derived active flavonoid, exhibits neuroprotection against ischemic brain injury and stimulates the levels of phosphorylation of extracellular signal-regulated kinase (pERK) and brain-derived neurotrophic factor (BDNF) expression in vivo. In this study, the antidepressant-like effects of baicalein was investigated using acute and chronic animal models of depression. The results showed that acute application of Bai at doses of 1, 2 and 4 mg/kg by intraperitoneal injection (i.p.) significantly reduced the immobility time in the forced swimming test (FST) and tail suspending test (TST) of mice. In addition, the chronic application of Bai by i.p. for 21 d also reduced the immobility time and improved locomotor activity in chronic unpredictable mild stress (CMS) model rats. Furthermore, it was shown that Bai reversed the reduction of extracellular ERKs phosphorylation and the level of BDNF expression in the hippocampus of CMS model rats. These results suggest that Bai produce an antidepressant-like effect and this effect is at least partly mediated by hippocampal ERK-mediated neurotrophic action.
Assuntos
Antidepressivos/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Depressão/tratamento farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Flavanonas/uso terapêutico , Fitoterapia , Scutellaria baicalensis/química , Animais , Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Depressão/metabolismo , Modelos Animais de Doenças , Flavanonas/farmacologia , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos , Atividade Motora/efeitos dos fármacos , Fosforilação , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Raízes de Plantas , Ratos , Ratos Sprague-Dawley , NataçãoRESUMO
AIM OF THE STUDY: Tanshinone IIA (Tan IIA) is one of the key components of Salvia miltiorrhiza Bunge that has been widely used for various cardiovascular and cerebrovascular disorders in Asian countries. Many studies have reported that Tan IIA has antioxidative properties, but whether Tan IIA can rescue neurons from oxidative insult has never been reported. The present study was undertaken to evaluate the possible neuroprotective effects of Tan IIA on hydrogen peroxide (H(2)O(2))-induced oxidative stress in rats. MATERIALS AND METHODS: H(2)O(2)-induced cytotoxicity was evaluated by the cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and flow cytometry with PI staining. Calcium imaging experiments were carried out to measure intracellular free calcium concentration. Western blotting was used to determine the expression of Bax and Bcl-2 protein. Electrophysiological studies in hippocampal slices were performed to investigate the effect of Tan IIA on synaptic function and cognitive impairment caused by H(2)O(2). RESULTS: It was found that pretreatment with Tan IIA protected primary rat cortical neurons against H(2)O(2)-induced cytotoxicity. Furthermore, Tan IIA markedly reduced the elevation of [Ca(2+)](i) evoked by H(2)O(2). Western blot analysis indicated that pretreatment with Tan IIA prevented the increase in Bax/Bcl-2 ratio induced by H(2)O(2). In addition, preincubation of Tan IIA 20 min prior to H(2)O(2) exposure could reverse H(2)O(2)-induced hippocampal LTP impairment, but without significant alteration in basal synaptic transmission and LTP induction. CONCLUSIONS: These findings demonstrate that Tan IIA might serve as a novel promising therapeutic agent for oxidative stress injury in neurodegenerative diseases.
Assuntos
Abietanos/farmacologia , Peróxido de Hidrogênio/toxicidade , Potenciação de Longa Duração/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Células Cultivadas , Feminino , Citometria de Fluxo , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Masculino , Neurônios/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
More and more attention in the field of drug discovery has been focused on the neuroprotection of natural compounds from traditional medicinal herbs. Cerebral ischemia is a complex pathological process involving a series of mechanisms, and a framework for the development of neuroprotectants from traditional herb medicine is a promising treatment for cerebral ischemia. Natural compounds with the effects of anti-oxidation, anti-inflammation, calcium antagonization, anti-apoptosis, and neurofunctional regulation exhibit preventive or therapeutic effects on experimental ischemic brain injury. According to the pharmacological mechanisms underlying neuroprotection, we evaluated natural products from traditional medicinal herbs that exhibit protective effects on ischemic brain injury and characterized the promising targets.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/uso terapêutico , Plantas Medicinais/química , Traumatismo por Reperfusão/prevenção & controle , Animais , Isquemia Encefálica/prevenção & controle , Humanos , Medicina Tradicional , Fármacos Neuroprotetores/química , Fitoterapia , Extratos Vegetais/químicaRESUMO
OBJECTIVE: To investigate physiologic effects of electroacupuncture (EA) combined with xylazine administration in goats. ANIMALS: 48 healthy crossbred goats. PROCEDURES: Goats were randomly allotted to 8 groups of 3 (nonpregnant and nonlactating) female goats and 3 male goats each. The 8 treatment groups were as follows: 1 EA group, 3 xylazine (0.1, 0.2, and 0.4 mg/kg, IM) groups, 3 EA plus xylazine (0.1, 0.2, and 0.4 mg/kg, IM) groups, and 1 control group. Electroacupuncture was performed for 90 minutes. Xylazine was administered 20 minutes after EA was performed. Pain threshold, heart rate, mean arterial pressure (MAP), respiration rate, and rectal temperature were observed at 0, 5, 25, 45, 65, and 85 minutes after xylazine administration. RESULTS: Xylazine administered at 0.4 mg/kg increased the pain threshold and reduced MAP. Xylazine administered at 0.1, 0.2, or 0.4 mg/kg reduced heart rate, respiration rate, and temperature. Electroacupuncture increased the pain threshold but had no effect on heart rate, MAP, respiratory rate, or rectal temperature. Pain threshold in goats that underwent EA plus xylazine administration was higher than in goats that received EA or xylazine alone. Electroacupuncture combined with xylazine at 0.1 mg/kg did not affect heart rate, MAP, respiratory rate, or rectal temperature. Pain threshold in goats that underwent EA plus xylazine administration at 0.1 mg/kg was higher than in goats given xylazine at 0.4 mg/kg alone. CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture combined with xylazine, even at 0.1 mg/kg, provided analgesia without significantly affecting cardiorespiratory parameters or rectal temperature in goats.
Assuntos
Analgésicos/farmacologia , Eletroacupuntura/veterinária , Cabras , Dor/veterinária , Xilazina/farmacologia , Agonistas alfa-Adrenérgicos/administração & dosagem , Agonistas alfa-Adrenérgicos/farmacologia , Analgésicos/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Dor/tratamento farmacológico , Xilazina/administração & dosagemRESUMO
Many natural polyphenolic compounds have been shown to attenuate reactive oxygen/nitrogen species (ROS/RNS) formation and protect against ischemia/reperfusion injury both in vitro and in vivo. 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside (TSG), an active component of the rhizome extract from Polygonum multiflorum, exhibits antioxidative and anti-inflammatory effects. Here, we used an in vitro ischemic model of oxygen-glucose deprivation followed by reperfusion (OGD-R) and an in vivo ischemic model of middle cerebral artery occlusion (MCAO) to investigate the neuroprotective effects of TSG on ischemia/reperfusion brain injury and the related mechanisms. We demonstrated that OGD-R-induced neuronal injury, intracellular ROS generation, and mitochondrial membrane potential dissipation were reversed by TSG. The elevation of H2O2-induced [Ca2+]i was also attenuated by TSG. Inhibition of the c-Jun N-terminal kinase (JNK) and Bcl-2 family-related apoptotic signaling pathway was involved in the neuroprotection afforded by TSG. Meanwhile, TSG inhibited iNOS mRNA expression induced by OGD-R, which may be mediated by the activation of SIRT1 and inhibition of NF-kappaB activation. In vivo studies further demonstrated that TSG significantly reduced the brain infarct volume and the number of positive cells by TUNEL staining in the cerebral cortex compared to the MCAO group. Our study indicates that TSG protects against cerebral ischemia/reperfusion injury through multifunctional cytoprotective pathways.
Assuntos
Antioxidantes/farmacologia , Encéfalo/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Glucosídeos/farmacologia , NF-kappa B/metabolismo , Estilbenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Células Cultivadas , Citoproteção/efeitos dos fármacos , Regulação para Baixo , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , NF-kappa B/genética , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Polygonum , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Nitrogênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidores , Rizoma , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/genética , Sirtuína 1/metabolismoRESUMO
Recent evidences indicate the existence of an atypical D(1) dopamine receptor other than traditional D(1) dopamine receptor in the brain that mediates PI hydrolysis via activation of phospholipase C(beta) (PLC(beta)). To further understand the basic physiological function of this receptor in brain, the effects of a selective phosphoinositide (PI)-linked D(1) dopamine receptor agonist SKF83959 on cytosolic free calcium concentration ([Ca(2+)](i)) in cultured rat prefrontal cortical astrocytes were investigated by calcium imaging. The results indicated that SKF83959 caused a transient dose-dependent increase in [Ca(2+)](i). Application of D(1) receptor, but not D(2), alpha(1) adrenergic, 5-HT receptor, or cholinergic antagonist prevented SKF83959-induced [Ca(2+)](i) rise, indicating that activation of the D(1) dopamine receptor was essential for this response. Increase in [Ca(2+)](i) was a two-step process characterized by an initial increase in [Ca(2+)](i) mediated by release from intracellular stores, supplemented by influx through voltage-gated calcium channels, receptor-operated calcium channels, and capacitative Ca(2+) entry. Furthermore, SKF83959-stimulated increase in [Ca(2+)](i) was abolished following treatment with a PLC inhibitor. Overall, these results suggested that activation of D(1) receptor by SKF83959 mediates a dose-dependent mobilization of [Ca(2+)](i) via the PLC signaling pathway in cultured rat prefrontal cortical astrocytes.
Assuntos
Astrócitos/metabolismo , Sinalização do Cálcio , Fosfatidilinositóis/metabolismo , Córtex Pré-Frontal/citologia , Receptores de Dopamina D1/metabolismo , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina/análogos & derivados , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/enzimologia , Canais de Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Feminino , Inositol 1,4,5-Trifosfato/metabolismo , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Fosfolipases Tipo C/metabolismoRESUMO
OBJECTIVE: To investigate the effects of total base of Sophora alopecuroides on expression of SOD, MDA, NO, MPO in rats with experimental colitis (UC). METHOD: SD rats were randomized into 6 groups and colitis was induced by administrating 2,4,6-trinitrobenzesulphonic acid (TNB) recatlly in rats. Rats were given drug by stomach after the first day for 3 weeks, and sacrificed at 23rd day to determine the content of MDA and activities of SOD, NO, MPO in colonic mucosa, and to estimate the symptom and colonic histology. RESULT: In UC rats, SOD was significantly decreased whereas MDA, NO, MPO were increased when compared with the normal group (P < 0.05). In all treatment groups, Sophora alopecuroides could increase SOD, decrease MDA, NO, MPO (P < 0.05), and improve the symptoms and histological damages. CONCLUSION: The total dose of S. alopecuroides may ameliorates or alleviate the symptoms of UC through inhibiting oxygen free radical reaction, decreasing the generation of NO and exerting anti-inflammatory effects.