RESUMO
Chlorogenic acid (CGA) is known to have antioxidant potentials, yet the effect of CGA on brain ischemia has not been sufficiently understood. Brain ischemia such as transient global ischemia disrupts many areas of the brain of rats, including the hippocampus. Male Wistar rats were randomly assigned into five groups, that is, sham-operated (SO), bilateral common carotid occlusion (BCCO), and BCCO+ 15, 30, and 60 mg/kg bw CGA groups (CGA15, CGA30, and CGA60, respectively). Brain ischemia was induced in Wistar rats with BCCO for 20 min followed by intraperitoneal injection of CGA. The rats were examined for the spatial memory in a Morris water maze test on the 3rd day and were euthanized on the 10th day after BCCO. The total number of pyramidal cells was estimated, and the mRNA expressions of Bcl2, Bax, caspase-3, SOD2, SOD1, GPx, ET-1, eNOS, CD31, and VEGF-A were measured. The BCCO group spent less time and distance in the target quadrant than any other group in the spatial memory retention test. The CA1 pyramidal cell numbers in the BCCO and CGA15 groups were lower than in the CGA30 and CGA60 groups. The mRNA expressions of Bcl2, SOD2, and CD31 in the BCCO group were lower than in the CGA15, CGA30, and CGA60 groups. The ET-1 expression was higher in the BCCO and CGA15 groups than in the SO, CGA30, and CGA60 groups. CGA improves the spatial memory and prevents the CA1 pyramidal cell death after BCCO by increasing Bcl2, SOD2, and CD31 expressions and decreasing ET-1 expression.
Assuntos
Isquemia Encefálica , Ácido Clorogênico , Animais , Isquemia Encefálica/tratamento farmacológico , Morte Celular , Hipocampo , Isquemia , Masculino , Aprendizagem em Labirinto , Transtornos da Memória , Ratos , Ratos WistarRESUMO
A number of studies have investigated the effects of ischemic injury on functional and cellular characteristics of hippocampus. There is only a limited study on vascular remodeling of it. The present study aimed at examining vascular remodeling in hippocampus and spatial memory disturbances after transient brain ischemia. Male Wistar rats were randomly divided into four groups, i.e. sham operated (SHAM), transient brain ischemia with 1 day reperfusion (IR1), 3 day reperfusion (IR3), and 10 days reperfusion (IR10) groups. Transient brain ischemia was induced by bilateral common carotid artery occlusion (BCCAO). The spatial memory test was performed using the Morris water maze (MWM) in SHAM and IR10 groups. The rats were euthanized at day 1, 3 or 10 after BCCAO depending on the groups. The mRNA expressions of SOD2, Bcl-2, NeuN, eNOS, endothelin-1 (ET-1), CD31, VE-cadherin and vascular remodeling of the hippocampus were examined. There were deteriorations of spatial learning ability in IR10 group. The percentages of SOD2 and Bcl-2, the expression of NeuN, decreased and the vascular remodeling was observed in the ischemic groups. The eNOS and CD31 expressions were less in IR10, the VE-cadherin expression was less in all ischemic groups than in SHAM group, while ET-1 expression in IR1 group was higher than any other groups. The spatial memory deterioration after BCCAO is associated with vascular remodeling in hippocampus, characterized by lumen narrowing and smooth muscle thickening of microvessels.
Assuntos
Hipocampo/irrigação sanguínea , Hipocampo/fisiopatologia , Ataque Isquêmico Transitório/psicologia , Transtornos da Memória/etiologia , Remodelação Vascular/fisiologia , Animais , Antígenos CD/genética , Antígenos Nucleares/genética , Caderinas/genética , Modelos Animais de Doenças , Endotelina-1/genética , Expressão Gênica , Genes bcl-2 , Hipocampo/fisiologia , Ataque Isquêmico Transitório/complicações , Ataque Isquêmico Transitório/patologia , Masculino , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/patologia , Transtornos da Memória/fisiopatologia , Proteínas do Tecido Nervoso/genética , Óxido Nítrico Sintase Tipo III/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Memória Espacial/fisiologia , Superóxido Dismutase/genética , Remodelação Vascular/genéticaRESUMO
Monosodium glutamate (MSG) is believed to exert deleterious effects on various organs, including the hippocampus, likely via the oxidative stress pathway. Garlic (Alium sativum L.), which is considered to possess potent antioxidant activity, has been used as traditional remedy for various ailments since ancient times. We have investigated the effects of black garlic, a fermented form of garlic, on spatial memory and estimated the total number of pyramidal cells of the hippocampus in adolescent male Wistar rats treated with MSG. Twenty-five rats were divided into five groups: C- group, which received normal saline; C+ group, which was exposed to 2 mg/g body weight (bw) of MSG; three treatment groups (T2.5, T5, T10), which were treated with black garlic extract (2.5, 5, 10 mg/200 g bw, respectively) and MSG. The spatial memory test was carried out using the Morris water maze (MWM) procedure, and the total number of pyramidal cells of the hippocampus was estimated using the physical disector design. The groups treated with black garlic extract were found to have a shorter path length than the C- and C+ groups in the escape acquisition phase of the MWM test. The estimated total number of pyramidal cells in the CA1 region of the hippocampus was higher in all treated groups than that of the C+ group. Based on these results, we conclude that combined administration of black garlic and MSG may alter the spatial memory functioning and total number of pyramidal neurons of the CA1 region of the hippocampus of rats.