Protective effects of Nigella sativa oil on propoxur-induced toxicity and oxidative stress in rat brain regions

Propoxur (PPr) is a widely used broad spectrum carbamate insecticide mainly used to control household pests. Because of the widespread use of pesticides for domestic and industrial applications, evaluation of their neurotoxic effects is of major concern to public health. The aim of the present study was to evaluate the possible protective effects of Nigella sativa oil (NSO), an antioxidant agent, against PPr-induced toxicity and oxidative stress in different brain regions of rats including cerebellum, cortex and hippocampus. In the present study, 32 male Sprague-Dawley rats were used and divided into four equal groups. Group 1 was allocated as the control group. Groups 2-4 were orally administered 1 ml/kg/bw/day NSO, 8.51 mg/kg/bw/day PPr or NSO plus PPr, respectively, for 30 days. Lipid peroxidation (LPO), protein carbonyl content (PCC) and acetylcholine esterase activity (AChE) were determined. Enzymatic antioxidant activities [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST)] and non-enzymatic antioxidants [reduced glutathione (GSH)] were determined. PPr treatment significantly increased the levels of LPO, PCC and oxidized glutathione (GSSG) in brain regions. On the contrary, levels of GSH and the activities of SOD, CAT, GSH-Px, GST and AChE were significantly decreased. NSO treatment to PPr intoxicated rats restored such biochemical parameters to within control levels except GST activity, emphasizing its antioxidant role. We conclude that NSO significantly reduces PPr-induced toxicity and oxidative stress in rat brain regions via a free radicals scavenging mechanism.     

Endosulfan-induced neurotoxicity and serum acetylcholinesterase inhibition in rabbits: The protective effect of Vit C

The neurotoxic effects and acetylcholinesterase inhibition induced by endosulfan, and the amelioration of these effects by Vitamin C (Vit C), were studied in the brains of New Zealand white rabbits. The cerebrum and cerebellum of each rabbit was examined grossly and histopathologically, and caspase-3 activity was determined by immunohistochemical methods. Twenty-four rabbits were divided into four groups (n = 6). Rabbits in Group I (END) were given a sublethal dose of endosulfan (1 mg/kg bw) in corn oil daily by oral gavage for 6 weeks. Group II (END + C) received the same dose of endosulfan and also Vit C (20 mg/kg bw) every second day during the 6 week period. Group III (OIL + C) received oral corn oil daily and Vit C every second day for 6 weeks. Group IV (OIL) received corn oil daily by oral gavage throughout the experiment. A significant reduction in acetylcholinesterase activity was observed in the END group, which was ameliorated in the END + C group. Hyperemia and slight hemorrhages in brains and cerebellums were seen in some rabbits in the END group. There were no gross cerebral or cerebellar lesions in the other groups. Hemorrhages, degenerations and slight gliosis were the marked histopathological findings of some rabbits belonging to the END group. A positive caspase-3 reaction was more severe in the END group than in the others. An ameliorating effect of Vit C on gross, histopathological, and immunohistochemical findings was observed in the END + C group. Thus, although endosulfan could cause neurotoxic effects in rabbits, this toxicity was decreased by Vit C treatment, which increased serum acetylcholinesterase activity.     

处理重组牛朊蛋白对接种金黄地鼠脑组织朊蛋白的效应

将纯化的重组牛朊蛋白经理化因子处理后,脑内接种金黄地鼠。临床观察200天后,对大脑、小脑和脑干,进行蛋白酶抗性朊蛋白的WesternBlot检测和朊蛋白基因表达绝对定量。结果表明,处理的重组牛朊蛋白对金黄地鼠脑组织检测部位的基因表达有特定的影响;接种后在检测时间内处理重组牛朊蛋白没有导致金黄地鼠脑内酶抗性朊蛋白的出现。研究结果为重组朊蛋白的生物学提供了基础数据。     

Effect of naoluo xintong on expression of Fas,Fas L in hippocampus CA1 area and Fas mRNA in the cortex of frontal or parietal lobe after local cerebral ischemia/reperfusion in MCAO rats

AIM: To investigate the effets of naoluo xintong on the expression of Fas, FasL protein in hippocampus CA1 area and Fas mRNA in the cortex of frontal or parietal lobe after local cerebral ischemia/reperfusion in MCAO rats. METHODS: The local cerebral ischemia /reperfusion model was established by intraluminal thread occlusion of the middle cerebral arteries (MCAO), the middle cerebral arteries of rats were occluded for 2 hours and reperfused for 1, 3 and 7 days. The animals were divided into pseudo surgery group(sham group), model group, Yiqi group, Huoxue group and naoluo xintong group. Using the techniques of immuno-histochemical staining and in situ hybridization, the expression of Fas and FasL was observed in hippocampus CA1 area, the expression of Fas mRNA was also observed in the cortex of frontal and parietal lobe. RESULTS: A value of Fas and FasL protein expression or A value and positive unit of Fas mRNA expression in control group were higher than those in sham in hippocampus CA1 area, the cortex of frontal or parietal lobe after local cerebral ischemia/reperfusion in MCAO rats (P<0.01). A value and/or positive unit of their expression in naoluo xintong group were lower than those in control group (P<0.05 or P<0.01). A value and/or positive unit of their expression in Yiqi and Huoxue groups were higher than those in naoluo xintong group for 3 and/or 7 days (P<0.05 or P<0.01). CONCLUSION: naoluo xintong could resist neuron apoptosis, alleviate pathologic injury after local cerebral ischemia/reperfusion in MCAO rats by inhibiting the expression of Fas, FasL protein and Fas mRNA.     

Study on the damage of auditory path of the experimental autoimmune encephalomyelitis

AIM: To explore if there is lesion in the auditory path in the brainstem of the Wistar rat with experimental autoimmune encephalomyelitis（EAE）.METHODS: EAE was induced by guinea pig spinal cord homogenate (GPSCH),then the evoked potential in both EAE and control groups was examined.The HE staining and myelin staining of the auditory nucleus were conducted in order to corroborate the damage of the auditory path in the brainstem.Through studying the pathological changes using light microscopy and behavior changes of rats,we defined that the model was successful.RESULTS: The latency period of auditory evoked potentials of EAE rats was much longer than that in control group.The pathological pictures manifested that auditory nucleus were invaded by a great number of lymphocytes,demyelinations were discovered in it.CONCLUSION: The auditory path in the brainstem of the Wistar rat with EAE is suffered from inflammation and demyelination.     

Effect of aminoguanidine on TNF-α,IL-1β and neuronal apoptosis after focal cerebral ischemic injury in rats

AIM: To evaluate the effect of aminoguanidine (AG) on inflammatory factors and neuronal apoptosis after focal cerebral ischemic injury in rats and the possible mechanism of protective effect of AG against cerebral ischemic injury.METHODS: Thirty male SD rats (weighing 250 g-280 g) were randomly divided into three groups: (1) sham operated group (SH group,n=10),(2) ischemic groups (IS group,n=10),(3) AG group (n=10).In AG group,AG at dose of 100 mg·kg-1 was given intraperitoneally twice a day for 3 consecutive days.In IS group,normal saline was given instead of AG.Focal cerebral ischemia was produced by middle cerebral artery occlusion (MCAO) for 12 h.A nylon thread with rounded tip was inserted into left internal carotid artery cranially until resistance was felt.The distance from bifurcation of common carotid artery to the tip of the thread was about 18-19 mm.Focal cerebral ischemia was confirmed by left Horners syndrome and right side hemiplegia.In SH group,the carotid artery was exposed but no thread was inserted.The expression of tumor necrosis factor-α(TNF-α) was determined by immunochemistry and the content of interleulin-1β(IL-1β) was measured by radioimmunoassay.The expressions of Bcl-2 and Bax protein were detected by flow cytometry.RESULTS: The expression of TNF-α and the content of IL-1β were markedly increased after MCAO.Significantly increased DNA fragmentation,the indication of apoptosis,was detected after MCAO.The expression of TNF-α and the content of IL-1β were significantly lower in AG group than those in IS group.The percentage of apoptosis cells and expression of Bax protein were markedly lower in AG group than those in IS group but still significantly higher than those in SH group.The expression of Bcl-2 protein was markedly higher in AG group than that in IS group.No significant difference in the expression of Bcl-2 protein between IS and SH group was observed.CONCLUSION: AG inhibits the increase in the expression of TNF-α and the content of IL-1β,and protects neurons from apoptosis induced by focal cerebral ischemia through increasing the Bcl-2 protein expression and inhibiting the Bax protein expression.     

Feline immunodeficiency virus infection: a valuable model to study HIV-1 associated encephalitis

Feline immunodeficiency virus (FIV), like human immunodeficiency virus (HIV)-1, is a neurotropic lentivirus and is associated with neuropathology in natural and experimental infections. FIV enters the brain early following experimental infection, and virus has been proposed to enter the brain via the blood–brain barrier and blood–CSF barrier, within infected lymphocytes and monocytes/macrophages. However the entry of cell-free virus or the direct infection of brain endothelial cells and astrocytes of the blood–brain barrier may also contribute to CNS infection. This review explores the role played by the FIV model in the elucidation of mechanism of lentiviral entry to the brain and viral interactions with the CNS, particularly in relation to lymphotropic lentiviruses.     

Wireless telemetry and analysis of electrical activity of infralimbic cortex in morphine-addicted rats

AIM：To telemeter and analyze the real-time changes of electrical activity of infralimbic cortex (IL) before and after preparation of the conditioned place preference (CPP) model in morphine-addicted rats. METHODS：The male SD rats were selected and randomly divided into morphine withdrawal group and normal saline control group (12 rats per group). An operation of brain stereotaxic electrode embedding was made. The CPP model of morphine-addicted rats was prepared by morphine injection and CPP training. The rats in control group received normal saline. The changes of CPP and electrical activity of IL in the rats were detected before and after modeling by CPP video system and electroencephalogram (EEG) wireless telemetry system. RESULTS：Compared with before modeling and control group, the time of withdrawal group staying in white box was prolonged significantly on withdrawal 1~3 d. Compared with control group, when the rats in withdrawal group stayed in white box on withdrawal 3 d, the electrical activity of IL showed that δ wave decreased obviously, and β wave (β 2) increased obviously, but no significant change of α wave and θ wave was observed. However, when the rats in withdrawal group shuttled from black box to white box, δ wave increased significantly, and α wave (α 1, α 2) and β wave (β 1, β 2) decreased significantly, but θ wave had no evident change. When the rats stayed in black box or shuttled from white box to black box, no significant difference of the electrical activity of IL between the 2 groups was detected. CONCLUSION：The change mechanism of electrical activity of IL may be different, when morphine-addicted rats shuttle to seek drug and stay in drug-related environment. There is possibly duality in neuronal function of IL.     

中华绒螯蟹脑和胸腹神经团的组织学观察

利用组织切片技术研究中华绒螯蟹(Eriocheir sinensis)脑和胸腹神经团的形态学和组织学结构。结果表明中华绒螯蟹的脑位于2个眼柄基部之间,由前脑、中脑、后脑和各部分发出的神经束组成;在脑的切片中可以观察到多种髓质和不同类型的细胞体群。中华绒螯蟹胸腹神经团呈圆盘状,靠近腹甲中央,向外发出多条神经束;在其切片中也可观察到多种类型的细胞体群。详细地描述了中华绒螯蟹的脑和胸腹神经团的组织学结构,为进一步研究中华绒螯蟹的神经分泌细胞奠定了基础,同时也为研究其它甲壳类生物的脑和胸腹神经团的组织结构提供参考。