RESUMO
BACKGROUND: Liver cirrhosis (LC) is one of the chronic liver diseases with high disability and mortality accompanying hepatic encephalopathy (HE) followed by cognitive dysfunctions. In this work, the effect of berberine (Ber) on spatial cognition was studied in a rat model of LC induced by thioacetamide (TAA). MATERIALS AND METHODS: Male Wistar rats (200-250 g) were divided into six groups: (1) control; (2) TAA, 200 mg/kg/day, i.p.; (3-5) TAA + Ber; received Ber (10, 30, and 60 mg/kg, i.p., daily after last TAA injection); (6) Dizocilpine (MK-801) + TAA, received MK-801 (2 mg/kg/day, i.p.) 30 m before TAA injection. The spatial memory, BBB permeability, brain edema, liver enzymes, urea, serum and brain total bilirubin, oxidative stress and cytokine markers in the hippocampus were measured. Furthermore, a histological examination of the hippocampus was carried out. RESULTS: The BBB permeability, brain edema, liver enzymes, urea, total bilirubin levels in serum and hippocampal MDA and TNF-α increased significantly after TAA injection (p < 0.001); the spatial memory was impaired (p < 0.001), and hippocampal IL-10 decreased (p < 0.001). Ber reversed all the above parameters significantly (p < 0.05, p < 0.01 and p < 0.001). MK-801 prevented the development of LC via TAA (p < 0.001). CONCLUSION: Results showed that Ber improves spatial learning and memory in TAA-induced LC by improving the BBB function, oxidative stress and neuroinflammation. Ber might be a promising therapeutic agent for cognitive improvement in LC.
RESUMO
Exposure to dust storm particulate matter (PM) is detrimental to kidney tissue. In this study, the impacts of chronic intake of dusty PM were explored as a major objective in a specified compartment to make a real-like dust storm (DS) model, and the role of hesperidin (HSP) as an antioxidant on kidney tissue was assessed in rats. Thirty-two male Wistar rats (200-220 g) were randomly allocated into 4 groups: CA+NS: (clean air and normal saline as a vehicle of HSP). Dusty PM and NS (DS+NS). HSP+ CA: rats received 200 mg/kg of HSP by gavage for 28 days, once daily in addition to exposure to clean air. HSP+DS: HSP plus DS. In DS groups, the animals were exposed to dust storms at a concentration of 5000-8000 µg/m3 in the chamber for 1 h daily, for 4 consecutive weeks, except Thursdays and Fridays. At the end of the experiment, the animals were sacrificed for biochemical, inflammatory, oxidative stress, molecular parameters, and histological evaluation. DS significantly enhanced blood urea nitrogen and creatinine, inflammatory (tumor necrosis factor-α, and interleukin-1ß), and oxidative stress indexes. Likewise, a significant increase was seen in mRNA Smads, collagen-I, and transforming growth factor-ß1 (TGF-ß1) expressions in the kidney. Histological findings showed contracted glomeruli and kidney structure disorder. In addition, Masson's trichrome staining demonstrated renal fibrosis. Nevertheless, HSP could significantly reverse these changes. Our data confirmed that DS results in kidney fibrosis through enhancing Smads/TGF-ß1 signaling. However, HSP was able to inhibit these changes as confirmed by histological findings.
Assuntos
Hesperidina , Nefropatias , Ratos , Masculino , Animais , Fator de Crescimento Transformador beta1/metabolismo , Hesperidina/farmacologia , Hesperidina/uso terapêutico , Material Particulado/toxicidade , Material Particulado/metabolismo , Ratos Wistar , Rim , Nefropatias/induzido quimicamente , Nefropatias/tratamento farmacológico , Nefropatias/prevenção & controle , Fibrose , PoeiraRESUMO
RATIONALE: Disorders caused by total sleep deprivation can be modulated by the administration of growth hormone, which could affect the expression of microRNA-9 and dopamine D2 receptor expressions followed by improvement in the hippocampal synaptic potential, spatial cognition, and inflammation in rats. OBJECTIVES: The present study aimed to elucidate the putative effects of exogenous growth hormone (GH) against total sleep deprivation (TSD)-induced learning and memory dysfunctions and possible involved mechanisms. METHODS: To induce TSD, rats were housed in homemade special cages equipped with stainless steel wire conductors to induce general and inconsistent TSD. They received a mild repetitive electric shock to their paws every 10 min for 21 days. GH (1 mg/kg, sc) was administered to adult young male rats once daily for 21-day-duration induction of TSD. Spatial learning and memory performance, inflammatory status, microRNA-9 (miR-9) expression, dopamine D2 receptor (DRD2) protein level, and hippocampal histological changes were assayed at scheduled times after TSD. RESULTS: The results indicated that TSD impaired spatial cognition, increased TNF-α, decreased level of miR-9, and increased DRD2 levels. Treatment with exogenous GH improved spatial cognition, decreased TNF-α, increased level of miR-9, and decreased DRD2 levels after TSD. CONCLUSIONS: Our findings suggest that GH may play a key role in the modulation of learning and memory disorders as well as the ameliorating abnormal DRD2-related functional disorders associated with miR-9 in TSD.
Assuntos
MicroRNAs , Privação do Sono , Ratos , Masculino , Animais , Privação do Sono/tratamento farmacológico , Fator de Necrose Tumoral alfa/metabolismo , Hipocampo/metabolismo , Receptores de Dopamina D2/metabolismo , Cognição , Inflamação/tratamento farmacológico , Inflamação/complicações , Hormônio do CrescimentoRESUMO
Total sleep deprivation (TSD) causes several harmful changes including anxiety, inflammation, and increased expression of extracellular signal-regulated kinase (ERK) and tropomyosin receptor kinase B (TrkB) genes in the hippocampus. The current study was conducted to explain the possible effects of exogenous GH against the above parameters caused by TSD and the possible mechanisms involved. Male Wistar rats were divided into 1) control, 2) TSD and 3) TSD + GH groups. To induce TSD, the rats received a mild repetitive electric shock (2 mA, 3 s) to their paws every 10 min for 21 days. Rats in the third group received GH (1 ml/kg, sc) for 21 days as treatment for TSD. The motor coordination, locomotion, the level of IL-6, and expression of ERK and TrkB genes in hippocampal tissue were measured after TSD. The motor coordination (p < 0.001) and locomotion indices (p < 0.001) were impaired significantly by TSD. The concentrations of serum corticotropin-releasing hormone (CRH) (p < 0.001) and hippocampal interleukin-6 (IL-6) (p < 0.001) increased. However, there was a significant decrease in the interleukin-4 (IL-4) concentration and expression of ERK (p < 0.001) and TrkB (p < 0.001) genes in the hippocampus of rats with TSD. Treatment of TSD rats with GH improved motor balance (p < 0.001) and locomotion (p < 0.001), decreased serum CRH (p < 0.001), IL-6 (p < 0.01) but increased the IL-4 and expression of ERK (p < 0.001) and TrkB (p < 0.001) genes in the hippocampus. Results show that GH plays a key role in modulating the stress hormone, inflammation, and the expression of ERK and TrkB genes in the hippocampus following stress during TSD.
Assuntos
Interleucina-4 , Privação do Sono , Ratos , Masculino , Animais , Privação do Sono/complicações , Privação do Sono/tratamento farmacológico , Ratos Wistar , Hormônio do Crescimento , Interleucina-6 , Hormônio Liberador da Corticotropina , InflamaçãoRESUMO
Neonatal seizures commonly caused by hypoxia can lead to long-term neurological outcomes. Early inflammation plays an important role in the pathology of these outcomes. Therefore, in the current study, we explored the long-term effects of Fingolimod (FTY720), an analog of sphingosine and potent sphingosine 1-phosphate (S1P) receptors modulator, as an anti-inflammatory and neuroprotective agent in attenuating anxiety, memory impairment, and possible alterations in gene expression of hippocampal inhibitory and excitatory receptors following hypoxia-induced neonatal seizure (HINS). Seizure was induced in 24 male and female pups (6 in each experimental group) at postnatal day 10 (P10) by premixed gas (5% oxygen/ 95% nitrogen) in a hypoxic chamber for 15 minutes. Sixty minutes after the onset of hypoxia, FTY720 (0.3 mg/kg) or saline (100 µl) was administered for 12 days (from P10 up to P21). Anxiety-like behavior and hippocampal memory function were assessed at P90 by elevated plus maze (EPM) and novel object recognition (NOR), respectively. Long-term potentiation (LTP) was recorded from hippocampal dentate gyrus region (DG) following stimulation of perforant pathway (PP). In addition, the hippocampal concentration of superoxide dismutase activity (SOD), malondialdehyde (MDA), and thiol as indices of oxidative stress were evaluated. Finally, the gene expression of NR2A subunit of N-Methyl-D-aspartic acid (NMDA) receptor, GluR2 subunit of (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) AMPA receptor and γ2 subunit of γ-Aminobutyric acid (GABAA) receptor were assessed at P90 by the quantitative real-time PCR. FTY720 significantly reduced later-life anxiety-like behavior, ameliorated object recognition memory and increased the amplitude and slope of the field excitatory postsynaptic potential (fEPSP) in the rats following HINS. These effects were associated with restoration of the hippocampal thiol content to the normal values and the regulatory role of FTY720 in the expression of hippocampal GABA and glutamate receptors subunits. In conclusion, FTY720 could restore the dysregulated gene expression of excitatory and inhibitory receptors. It also increased the reduced hippocampal thiol content, which was accompanied with attenuation of HINS-induced anxiety, reduced the impaired hippocampal related memory, and prevented hippocampal LTP deficits in later life following HINS.
Assuntos
Epilepsia , Potenciação de Longa Duração , Ratos , Animais , Masculino , Feminino , Potenciação de Longa Duração/fisiologia , Cloridrato de Fingolimode/farmacologia , Hipocampo , Convulsões , Hipóxia , Transtornos da Memória/etiologia , Receptores de N-Metil-D-Aspartato , Ácido gama-Aminobutírico/farmacologiaRESUMO
Neuroinflammation is a key pathological event triggering neurodegenerative process, resulting in neurologic sequelae. Curcumin (cur) has recently received increasing attention due to its anti-inflammatory properties. Therefore, we investigated the protective effects of curcumin on lipopolysaccharide (LPS)-induced memory impairments, long-term potentiation (LTP) deficits, hippocampal inflammatory cytokines, and neuronal loss in male rats. Rats were randomly divided into four groups as follows: (1) Vehicle; (2) cur; (3) LPS; and (4) cur/LPS. Following curcumin pretreatment (50 mg/kg, per oral via gavage, 14 consecutive days), animals received a single dose of LPS (1 mg/kg, intraperitoneally) or saline. Twenty-four hours after LPS/or saline administration, passive avoidance test (PAT), hippocampal LTP, inflammatory cytokines (TNFα, IL-1ß), and neuronal loss were assessed in hippocampal tissue of rats. Our results indicated that pretreatment with curcumin in LPS-challenged rats attenuates memory impairment in PAT, which was accompanied by significant increase in the field excitatory post-synaptic potential (fEPSP) slope and population spike (PS) amplitude. Hence, pretreatment with curcumin in LPS-treated rats decreased hippocampal concentration of tumor necrosis factor-alpha (TNF-α) and interleukin-1ß (IL-1ß), as well as reduced neuronal loss in the hippocampal tissue. This study provide evidence that pretreatment with curcumin attenuates LPS-induced memory impairment and LTP deficiency, which may be partly related to the amelioration of inflammatory cytokines and neuronal loss in the hippocampal tissue.
Assuntos
Curcumina , Citocinas , Ratos , Masculino , Animais , Citocinas/metabolismo , Lipopolissacarídeos/farmacologia , Potenciação de Longa Duração , Curcumina/farmacologia , Curcumina/uso terapêutico , Hipocampo/metabolismo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Fator de Necrose Tumoral alfaRESUMO
It has been consistently found that exposure to ambient air pollution, such as particulate matter (PM), results in cognitive impairments and mental disorders. This study aimed to investigate the possible neuroprotective effects of curcumin, a polyphenol compound, on the neurobehavioral deficits and to identify the role of oxidative stress in dusty PM exposure rats. Rats received curcumin (50 mg/kg, daily, gavage, 2 weeks) 30 min before placing animals in a clean air chamber (≤ 150 µg/m3, 60 min daily, 2 weeks) or ambient dusty PM chamber (2000-8000 µg/m3, 60 min daily, 2 weeks). Subsequently, the cognitive and non-cognitive functions of the animals were evaluated using standard behavioral tests. Moreover, blood-brain barrier (BBB) permeability, brain water content (BWC), oxidative-antioxidative status, and histological changes were determined in the cerebral cortex and hippocampal areas of the rats. Our results showed that curcumin administration in dusty PM exposure rats attenuates memory impairment, decreases anxiety-/depression-like behaviors, and improves locomotor/exploratory activities. These findings were accompanied by reduced BBB permeability and BWC, decreasing oxidative stress, and lessening neuronal loss in the cerebral cortex and different hippocampal areas. The results of this study suggest that curcumin's antioxidant properties may contribute to its efficacy in improving neurobehavioral deficits and preventing neuronal loss associated with dusty PM exposure.
Assuntos
Curcumina , Material Particulado , Ratos , Animais , Material Particulado/toxicidade , Poeira , Curcumina/farmacologia , Curcumina/uso terapêutico , Encéfalo , Estresse Oxidativo , Antioxidantes/farmacologia , Antioxidantes/uso terapêuticoRESUMO
INTRODUCTION: Non-motor symptoms (NMS) have high prevalence in patients with Parkinson's disease (PD). These symptoms are mainly the result of increased oxidative stress and neuronal damage. In this study we investigated the possible neuroprotective effects of anethole as a potent antioxidant on rotenone-induced behavioral deficits, hippocampal neuronal death, and oxidative stress profile in rats. METHODS: Male Wistar rats were administered with anethole (62.5, 125, and 250 mg/kg, i.g) concomitantly with rotenone (2 mg/kg, s.c) for 35 days. Shuttle box and novel object recognition tests were performed to determine cognitive functions, and tail flick test was used to measure pain sensitivity. The levels of BDNF, MDA, SOD, and GPx were assayed in the hippocampus. Hippocampal neuronal damage was evaluated using cresyl violet staining technique. RESULTS: Chronic administration of rotenone induced cognitive deficit and reduced thermal pain threshold. Rotenone also decreased SOD and GPx activities, increased MDA level, and reduced the expression of BDNF in the hippocampus. In addition, hippocampal neuronal loss was increased in rotenone treated rats. Treatment with high dose of anethole (250 mg/kg) improved cognitive function and increased pain threshold in all three doses (62.5, 125, and 250 mg/kg). Despite the unchanged SOD and GPx activities, hippocampal levels of MDA was significantly decreased after high-dose anethole treatment. Moreover, High dose of anethole increased the number of surviving neurons in the hippocampus, but couldn't increase the BDNF expression. CONCLUSION: Our findings indicated that anethole has antioxidant and neuroprotective effects against non-motor disorders induced by rotenone toxicity.
Assuntos
Fármacos Neuroprotetores , Doença de Parkinson , Animais , Ratos , Masculino , Rotenona/farmacologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson/metabolismo , Antioxidantes/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ratos Wistar , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Modelos Animais de DoençasRESUMO
OBJECTIVE: Total sleep deprivation (TSD) causes several harmful changes in the brain, including memory impairment, increased stress and depression levels, as well as reduced antioxidant activity. Growth hormone (GH) has been shown to boost antioxidant levels while improving memory and depression. The present study was conducted to explain the possible effects of exogenous GH against behavioral and biochemical disorders caused by TSD and the possible mechanisms involved. MAIN METHODS: To induce TSD, rats were housed in homemade special cages equipped with stainless steel wire conductors to induce general and inconsistent TSD. They received a mild repetitive electric shock to their paws every 10 min for 21 days. GH (1 ml/kg, sc) was administered to rats during induction of TSD for 21 days. Memory retrieval, anxiety, depression-like behaviors, pain behaviors, antioxidant activity, hippocampal level of BDNF, and simultaneously brain electrical activity were measured at scheduled times after TSD. KEY FINDINGS: The results showed that GH treatment improved memory (p < 0.001) in the PAT test of rats exposed to TSD. These beneficial effects were associated with lowering the level of anxiety and depression-like behavior (p < 0.001), rising the pain threshold (p < 0.01), increasing the activity of antioxidants (p < 0.01), hippocampal BDNF (p < 0.001), and regular brain electrical activity. SIGNIFICANCE: Our findings show that GH plays a key role in modulating memory, anxiety and depression behaviors, as well as reducing oxidative stress and improve hippocampal single-unit activity in the brain during TSD.
Assuntos
Antioxidantes , Privação do Sono , Animais , Ratos , Privação do Sono/complicações , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo , Hormônio do Crescimento/uso terapêutico , Transtornos da Memória/etiologia , Transtornos da Memória/complicaçõesRESUMO
Oxidative stress is a well-known risk factor for the development of anxiety and depression disorders. Curcumin, a natural compound, is an antioxidant with well-known neuroprotective functions. In the present study, we aimed to investigate the putative anxiolytic and antidepressant-like properties of curcumin, and its protective effects on blood-brain barrier (BBB) dysfunction and brain edema in lipopolysaccharide (LPS)-challenged rats, and the potential involvement of antioxidant properties of curcumin pretreatment. For this purpose, rats received 50 mg/kg of curcumin (gavage, 14 consecutive days) or saline prior to intraperitoneal administration of LPS. Subsequently, animals were submitted to the elevated plus maze (EPM), open field tests (OFT), and forced swimming test (FST), 24 h after LPS administration. Furthermore, BBB permeability and brain water contents were assessed in the brain tissue. Hence, GPX and SOD enzyme activity and MDA concentration were determined in the brain tissue using ELISA assay. Our results showed that curcumin significantly reduced LPS-induced anxiety-like behavior in EPM and OFT, increased exploratory activity, but without significant change in the locomotor activity. Pretreatment with curcumin attenuate LPS-induced BBB permeability and brain water content. Our biochemical assays showed that curcumin significantly increased the activity of SOD and GPX enzymes, as well as reduced MDA concentration in the brain tissue after LPS administration. Together, these results suggest that pretreatment with curcumin might mitigate LPS- induced anxiety and depressive-like behaviors, and attenuate brain edema and BBB permeability, possibly by its antioxidant properties.
Assuntos
Edema Encefálico , Curcumina , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Ansiedade/induzido quimicamente , Ansiedade/tratamento farmacológico , Barreira Hematoencefálica/metabolismo , Edema Encefálico/tratamento farmacológico , Curcumina/farmacologia , Curcumina/uso terapêutico , Depressão/induzido quimicamente , Depressão/tratamento farmacológico , Lipopolissacarídeos/farmacologia , Masculino , Estresse Oxidativo , Ratos , Superóxido Dismutase/metabolismo , Água/farmacologiaRESUMO
OBJECTIVES: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome that causes brain disturbances. Thymoquinone (TQ) has a wide spectrum of activities such as antioxidant, anti-inflammatory, and anticancer. This study aimed to evaluate the effects of TQ on spatial memory and hippocampal long-term potentiation (LTP) in rats with thioacetamide (TAA)-induced liver injury and hepatic encephalopathy. MATERIALS AND METHODS: Adult male Wistar rats were divided into six groups randomly: 1) Control; 2) HE, received TAA (200 mg/kg); 3-5) Treated groups (HE+TQ5, HE+TQ10, and HE+TQ20). TQ (5, 10, and 20 mg/kg) was injected intraperitoneally (IP) for 12 consecutive days from day 18 to 29. Subsequently, spatial memory performance was evaluated by the Morris water maze paradigm and hippocampal LTP was recorded from the dentate gyrus (DG) region. Activity levels of Malondialdehyde (MDA) and superoxide dismutase (SOD) were measured in the hippocampal tissue. RESULTS: Data showed that the hippocampal content of MDA was increased while SOD activities were decreased in TAA-induced HE. TQ treatment significantly improved spatial memory and LTP. Moreover, TQ restored the levels of MDA and SOD activities in the hippocampal tissue in HE rats. CONCLUSION: Our data confirm that TQ could attenuate cognitive impairment and improve LTP deficit by modulating the oxidative stress parameters in this model of HE, which leads to impairment of spatial cognition and LTP deficit. Thus, these results suggest that TQ may be a promising agent with positive therapeutic effects against liver failure and HE defects.
RESUMO
Hepatic encephalopathy (HE) is a prevalent complication of the central nervous system (CNS) that is caused by acute or chronic liver failure. This study was designed to evaluate the effects of thymoquinone (TQ) on thioacetamide (TAA)-induced HE in rats, and determine the consequential behavioral, biochemical, and histological changes. HE was induced in male Wistar rats by intraperitoneal (i.p.) injection of 200 mg/kg TAA once every 48 h for 14 consecutive days. Control groups received the normal saline containing 5 % DMSO. Thymoquinone (5, 10, and 20 mg/kg) was administered for ten consecutive days intraperitoneally (i.p.) after HE induction and it was continued until the end of the tests. Then, the passive avoidance memory, extracellular single unit, BBB permeability, and brain water content were evaluated. Moreover, hippocampal tissues were used for evaluation of oxidative stress index, inflammatory biomarkers, and histological parameters following HE. As result of the treatment, TQ improved passive avoidance memory, increased the average number of simultaneous firing of spikes/bins, improved the integrity of BBB, and decreased brain water content in the animal model of HE. Furthermore, the results indicated that treatment with TQ decreased the levels of inflammatory cytokines (TNF-α and IL-1ß) but increased the levels of glutathione (GSH) and anti-inflammatory cytokine (IL-10) of the surviving cells in the hippocampal tissues. This study demonstrates that TQ may have beneficial therapeutic effects on cognitive, oxidative stress, neuroinflammatory, and histological complications of HE in rat.
Assuntos
Benzoquinonas/farmacologia , Encefalopatia Hepática/tratamento farmacológico , Inflamação/tratamento farmacológico , Transtornos da Memória/tratamento farmacológico , Memória/efeitos dos fármacos , Animais , Glutationa/metabolismo , Encefalopatia Hepática/induzido quimicamente , Encefalopatia Hepática/metabolismo , Encefalopatia Hepática/patologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Masculino , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Tioacetamida , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Hepatic encephalopathy (HE) is a cerebral function alteration in patients with liver dysfunction. The present study aimed to evaluate the therapeutic effects of thymoquinone (TQ) on behavioral deficits and its possible mechanism(s) in a thioacetamide (TAA)-induced HE model. HE was induced in male Wistar rats by intraperitoneal (i.p.) injection of TAA (200 mg/kg) for once every 48 h for 14 consecutive days. Thymoquinone (5, 10, and 20 mg/kg) was administered for seven consecutive days (i.p.) after HE induction. Anxiety and depression-like behaviors assessed by standard paradigms respectively. Finally, their brain hippocampus sections prepared to evaluate the oxidative stress changes in rats. Data showed treatment HE rats with TQ ameliorated anxiety and depression-like behaviors. TQ administration also reduced oxidative stress due to its potential to enhance the levels of glutathione-peroxidase (GPx), catalase (CAT), and total thiol content in the hippocampus. These findings suggest that TQ has notable effects against acute hepatic failure and HE complications through modulation of oxidative stress.
Assuntos
Benzoquinonas/uso terapêutico , Encefalopatia Hepática/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos dos fármacos , Tioacetamida/toxicidade , Animais , Benzoquinonas/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Encefalopatia Hepática/induzido quimicamente , Encefalopatia Hepática/metabolismo , Hipocampo/química , Hipocampo/metabolismo , Locomoção/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Ratos , Ratos WistarRESUMO
OBJECTIVES: Exposure of healthy subjects to ambient airborne dusty particulate matter (PM) causes brain dysfunction. This study aimed to investigate the effect of sub-chronic inhalation of ambient PM in a designed special chamber to create factual dust storm (DS) conditions on spatial cognition, hippocampal long-term potentiation (LTP), inflammatory cytokines, and oxidative stress in the brain tissue. METHODS: Adult male Wistar rats (250-300 g) were randomly divided into four groups: Sham (clean air, the concentration of dusty PM was <150 µg/m3), DS1 (200-500 µg/m3), DS2 (500-2000 µg/m3) and DS3 (2000-8000 µg/m3). Experimental rats were exposed to clean air or different sizes and concentrations of dust PM storm for four consecutive weeks (exposure was during 1-4, 8-11, 15-16 and 20-23 days, 30 min, twice daily) in a real-ambient dust exposure chamber. Subsequently, cognitive performance, hippocampal LTP, blood-brain barrier (BBB) permeability and brain edema of the animals evaluated. As well as, inflammatory cytokines and oxidative stress indexes in the brain tissue measured using ELISA assays. RESULTS: Exposing to dust PM impaired spatial memory (p < 0.001), hippocampal LTP (p < 0.001). These disturbances were in line with the severe damage to respiratory system followed by disruption of BBB integrity (p < 0.001), increased brain edema (p < 0.001), inflammatory cytokines (p < 0.001) excretion and oxidative stress (p < 0.001) in brain tissue. CONCLUSIONS: Our study showed that exposure to ambient dust PM increased brain edema and BBB permeability, induced memory impairment and hippocampal LTP deficiency by increasing the inflammatory responses and oxidative stress in the brain of the rats.
Assuntos
Edema Encefálico/induzido quimicamente , Encéfalo/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/efeitos adversos , Memória Espacial/efeitos dos fármacos , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Exposição por Inalação/efeitos adversos , Masculino , Tamanho da Partícula , Ratos , Ratos WistarRESUMO
INTRODUCTION: To study the effect of gallic acid (GA) on hippocampal long-term potentiation (LTP) and histological changes in animal model of Alzheimer disease (AD) induced by beta-amyloid (Aß). METHODS: Sixty-four adult male Wistar rats (300±20 g) were divided into 8 groups: 1) Control (Cont); 2) AD; 3) Sham; 4-7) AD+GA (50, 100, and 200 mg/kg for 10 days, orally) or vehicle, 8) Cont+GA100, Aß (1µg/µL in each site) was infused into hippocampus bilaterally. Changes of amplitude and slope of LTP induced in hippocampal dentate gyrus (DG) were evaluated by high frequency stimulation (HFS) of perforant path (PP). RESULTS: Data showed that LTP amplitude and area under curve significantly impaired in AD rats (P<0.001), while significantly improved in AD rats treated with GA (P<0.05, P<0.01). CONCLUSION: Current findings suggest that GA reduces neural damage and brain amyloid neuropathology and improves cognitive function via free radicals scavenging and inhibiting oligomerization of Aß but with no effect on healthy rats.
RESUMO
A low-cost and simple cooling-assisted headspace liquid-phase microextraction device for the extraction and determination of 2,6,6-trimethyl-1,3 cyclohexadiene-1-carboxaldehyde (safranal) in Saffron samples, using volatile organic solvents, was fabricated and evaluated. The main part of the cooling-assisted headspace liquid-phase microextraction system was a cooling capsule, with a Teflon microcup to hold the extracting organic solvent, which is able to directly cool down the extraction phase while the sample matrix is simultaneously heated. Different experimental factors such as type of organic extraction solvent, sample temperature, extraction solvent temperature, and extraction time were optimized. The optimal conditions were obtained as: extraction solvent, methanol (10 µL); extraction temperature, 60°C; extraction solvent temperature, 0°C; and extraction time, 20 min. Good linearity of the calibration curve (R(2) = 0.995) was obtained in the concentration range of 0.01-50.0 µg/mL. The limit of detection was 0.001 µg/mL. The relative standard deviation for 1.0 µg/mL of safranal was 10.7% (n = 6). The proposed cooling-assisted headspace liquid-phase microextraction device was coupled (off-line) to high-performance liquid chromatography and used for the determination of safranal in Saffron samples. Reasonable agreement was observed between the results of the cooling-assisted headspace liquid-phase microextraction high-performance liquid chromatography method and those obtained by a validated ultrasound-assisted solvent extraction procedure.
Assuntos
Temperatura Baixa , Cicloexenos/análise , Microextração em Fase Líquida , Terpenos/análise , Compostos Orgânicos Voláteis/química , Cápsulas/química , Tamanho da Partícula , Solventes/químicaRESUMO
Ultrasound-assisted headspace solid-phase microextraction (UA-HS-SPME) and hydrodistillation (HD) methods, coupled to gas chromatography-mass spectrometry (GC-MS), were used for the extraction and analysis of volatile compounds from Hypericum perforatum and Hypericum scabrum collected from two different sites in Iran. In the UA-HS-SPME method, various experimental parameters such as the type of fiber coating, sonication time, extraction time, extraction temperature and desorption time were investigated. The highest extraction efficiency was achieved by a 100-µm polydimethylsiloxane (PDMS) fiber. Consequently, 36 compounds were identified in H. perforatum and H. scabrum samples, using the UA-HS-SPME-GC-MS method, of which 14 were the same in both species. On the other hand, 57 compounds of these species were identified by the HD-GC-MS method, of which 21 were the same. The predominant constituents identified using the UA-HS-SPME method in H. perforatum included ß-caryophyllene, α-pinene, γ-cadinene, α-selinene, germacrene-D, limonene and myrcene, and in H. scabrum were α-pinene, nonane, ß-pinene and limonene. The common constituents identified by the HD-GC-MS method for H. perforatum involved germacrene-D, limonene, ß-caryophyllene, α-pinene, ß-pinene and germacrene-B, and for H. scabrum were α-pinene, ß-pinene, germacrene-D, nonane, limonene and γ-cadinene. The results about the main constituents of the examined species correspond to the findings of other researchers. Additionally, comparing UA-HS-SPME-GC-MS and HD-GC-MS methods showed that the UA-HS-SPME-GC-MS method is much faster and simpler, and it requires much less sample size and lower temperature.