8-Hydroxyquinolylnitrones as multifunctional ligands for the therapy of neurodegenerative diseases

We describe the development of quinolylnitrones (QNs) as multifunctional ligands inhibiting cholinesterases (ChEs: acetylcholinesterase and butyrylcholinesterase-hBChE) and monoamine oxidases (hMAO-A/B) for the therapy of neurodegenerative diseases. We identified QN 19, a simple, low molecular weight nitrone, that is readily synthesized from commercially available 8-hydroxyquinoline-2-carbaldehyde. Quinolylnitrone 19 has no typical pharmacophoric element to suggest ChE or MAO inhibition, yet unexpectedly showed potent inhibition of hBChE (IC50 = 1.06 ± 0.31 nmol/L) and hMAO-B (IC50 = 4.46 ± 0.18 μmol/L). The crystal structures of 19 with hBChE and hMAO-B provided the structural basis for potent binding, which was further studied by enzyme kinetics. Compound 19 acted as a free radical scavenger and biometal chelator, crossed the blood-brain barrier, was not cytotoxic, and showed neuroprotective properties in a 6-hydroxydopamine cell model of Parkinson's disease. In addition, in vivo studies showed the anti-amnesic effect of 19 in the scopolamine-induced mouse model of AD without adverse effects on motoric function and coordination. Importantly, chronic treatment of double transgenic APPswe-PS1δE9 mice with 19 reduced amyloid plaque load in the hippocampus and cortex of female mice, underscoring the disease-modifying effect of QN 19.

Inhibition connexin 43 by mimetic peptide Gap27 mediates protective effects on 6-hydroxydopamine induced Parkinson's disease mouse model / 北京大学学报(医学版)

OBJECTIVE@#To explore whether the using of mimetic peptide Gap27, a selective inhibitor of connexin 43 (Cx43), could block the death of dopamine neurons and influence the expression of Cx43 in 6-hydroxydopamine (6-OHDA)-induced Parkinson's disease mouse models.@*METHODS@#Eighteen C57BL/6 mice were randomly divided into control group, 6-OHDA group and 6-OHDA+Gap27 group, with 6 mice in each group. Bilateral substantia nigra stereotactic injection was performed. The control group was injected with ascorbate solution, 6-OHDA group was injected with 6-OHDA solution, and 6-OHDA+Gap27 group was injected with 6-OHDA and Gap27 mixed solution. Immuno-histochemical staining was used to detect the number of dopamine neurons, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of Cx43 messenger ribonucleic acid (mRNA), immuno-fluorescence staining was used to detect the distribution of Cx43 protein, the contents of Cx43 protein and Cx43 phosphorylation at serine 368 (Cx43-ps368) in mouse midbrain were detected by Western blot.@*RESULTS@#After injection of 6-OHDA, numerous dopamine neurons in substantia nigra died as Cx43 content increased, Cx43-ps368 content decreased. Mixing Gap27 while injecting 6-OHDA could reduce the number of death dopamine neurons and weaken the changes of Cx43 and Cx43-ps368 content caused by 6-OHDA. The number of tyrosine hydroxylase (TH) immunoreactive positive neurons in 6-OHDA group decreased to 27.7% ± 0.02% of the control group (P < 0.01); The number of TH immunoreactive positive neurons in 6-OHDA+Gap27 group was (1.64±0.16) times higher than that in 6-OHDA group (P < 0.05); The content of total Cx43 protein in 6-OHDA group was (1.44±0.07) times higher than that in 6-OHDA+Gap27 group (P < 0.05) while (1.68±0.07) times higher than that in control group (P < 0.01). In 6-OHDA group, the content of Cx43-ps368 protein and its proportion in total Cx43 protein were significantly lower than that in 6-OHDA+Gap27 group (P < 0.05).@*CONCLUSION@#In 6-OHDA mouse models, mimetic peptide Gap27 played a protective role in reducing the damage to substantia nigra dopamine neurons, which was induced by 6-OHDA. The overexpression of Cx43 protein might have neurotoxicity to dopamine neuron. Meanwhile, decreasing Cx43 protein level and keeping Cx43-ps368 protein level may be the protective mechanisms of Gap27.

Expression of dopamine receptors in rat olfactory bulb and its role in hyposmia of Parkinson' s disease rat model / 解剖学报

Objective: To observe the localization and expression of dopamine receptors in olfactory bulb (OB) of rats and explore the effect of L-levodopa (L-DOPA) treatment on hyposmia in Parkinson' s disease (PD) rat model. Methods: Western blotting, immunohistochemistry and immunofluorescence were used to observe the expression and localization of dopamine receptors in the OB. PD rat model was established by bilateral 6-hydroxy dropamine(6-OHDA) injection to detect the effect of L-DOPA treatment on the hyposmia and the expression of glutamic decarboxylase (GAD) and brain derived neurotrophic factor (BNDF) of PD rats. Results Dl and D2 receptors were the major subtypes in the OB.D1 and D2 receptors were expressed by GAD positive Î3-aminobutyric acid (GABA) ergic neurons in the granule cell layer(GCL) which surrounded by tyrosine hydroxylase (TH) positive nerve fibers. The expression of TH in the GCL layer of PD rats decreased significantly (0. 05±0. 01 vs 0. 01±0. 00,P<0. 001). After L-DOPA treatment, the time of finding food balls in PD rats was significantly reduced [(624. 4±113.4)s vs (312. 4±79. 35) s, P<0.05]and the expression of BDNF in the OB was increased (0. 02±0. 01 vs 0. 07±0. 01, P<0. 01). Conclusion Dl and D2 are expressed in the GABAergic neurons in the GCL layer of OB. L-DOPA treatment alleviates the hyposmia of PD rats, which may be related to the D1-D2 receptor heteromeractivation and its downstream BDNF expression of GABAergic neurons.

7,8,4′-Trihydroxyisoflavone, a Metabolized Product of Daidzein, Attenuates 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Cells

Daidzein isolated from soybean (Glycine max) has been widely studied for its antioxidant and anti-inflammatory activities. However, the protective effects of 7,8,4′-trihydroxyisoflavone (THIF), a major metabolite of daidzein, on 6-hydroxydopamine (OHDA)-induced neurotoxicity are not well understood. In the current study, 7,8,4′-THIF significantly inhibited neuronal cell death and lactate dehydrogenase (LDH) release induced by 6-OHDA in SH-SY5Y cells, which were used as an in vitro model of Parkinson's disease (PD). Moreover, pretreatment with 7,8,4′-THIF significantly increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) activity in 6-OHDA-induced SH-SY5Y cells. In addition, 7,8,4′-THIF significantly recovered 6-OHDA-induced cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), increased Bax, and decreased Bcl-2 levels. Additionally, 7,8,4′-THIF significantly restored the expression levels of phosphorylated c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), phosphatidylinositol 3-kinases (PI3K)/Akt, and glycogen synthase kinase-3 beta (GSK-3β) in 6-OHDA-induced SH-SY5Y cells. Further, 7,8,4′-THIF significantly increased the reduced tyrosine hydroxylase (TH) level induced by 6-OHDA in SH-SY5Y cells. Collectively, these results suggest that 7,8,4′-THIF protects against 6-OHDA-induced neuronal cell death in cellular PD models. Also, these effects are mediated partly by inhibiting activation of the MAPK and PI3K/Akt/GSK-3β pathways.

Evaluation of the protective effect of Paeonia emodi Wall on rat model of Parkinson’s disease induced by 6 hydroxy dopamine

Background: Generation of reactive oxygen species together with paucity of antioxidant defense is considered as an important cause for dopaminergic neuronal death. Review of literature indicates that none of the drugs so far studied for preventing the PD were found to be promising for use. Therefore, the present study was planned to evaluate the neuroprotective effect of Paeonia emodi Wall (PEW) in 6-hydroxy dopamine induced Parkinson’s disease (PD) model.Methods: The study was conducted on Wistar rats where Parkinson’s disease was induced by producing the striatal 6-hydroxy dopamine lesions. The test animals received ethanolic extract of PEW at dose of 200 and 300mg/kg for 28 days. Circling behavior, spontaneous locomotor activity, muscular coordination and akinesia were studied. Antioxidant levels were assessed by biochemical estimation and histopathology was carried out for dopaminergic neuronal loss.Results: PEW ethanolic extract showed significant dose dependent recovery in number of circlings, line crossing, muscular coordination and akinesia. A significant increase in MDA levels and decreased GSH level in PEW treated groups was observed in test groups as compared to control group (p<0.05). Normal architecture was retained only in PEW 300mg/Kg (p<0.05). L-Dopa did not showed effect on biochemical and histological parameters.Conclusions: The ethanolic extract of PEW showed neuroprotective activity against 6-hydroxy dopamine induced Parkinson’s disease in rats in both 200 and 300mg/kg doses. The protective action of PEW in PD can be because of its ability to reduce the oxidative stress.

The protective effects of Citrus aurantium flower extract against 6-hydroxydopamine-mediated cell damage in human neuroblastoma SH-SY5Y cells / Los efectos protectores del extracto de flor de Citrus aurantium contra el daño celular mediado por 6-hidroxidopamina en células humanas de neuroblastoma SH-SY5Y

Parkinson's disease (PD) is described as a neurological condition, resulting from continuous degeneration of dopaminergic neurons. Currently, most treatments for neurodegenerative diseases are palliative. In traditional Iranian medicine, Citrus aurantium flower extract is used to treat some neural diseases, such as sleep disorders and anxiety. The tendency towards the use of medicinal herbs for the treatment of diseases (eg, seizure) is growing. Accordingly, we evaluated the antioxidant effects of C. aurantium flowers and analyzed their protective effects against 6-hydroxydopamine (6-OHDA)-mediated oxidative stress. In this study, 150 mM of 6-OHDA was used to induce cellular damage. Also, MTT assay was performed to analyze cellular viability. Fluorescence spectrophotometry was performed to measure the intracellular reactive oxygen species (ROS) and calcium levels. Based on the findings, 6-OHDA could reduce cell viability. We also analyzed the effects of C. aurantium against neurotoxicity. The intracellular levels of ROS and calcium greatly improved in cells exposed to 6-OHDA. SH-SY5Y cell incubation with C. aurantium (400 and 600 mg/mL) induced protective effects and decreased the biochemical markers of cell apoptosis. According to the findings, C. aurantium showed protective effects against neurotoxicity, caused by 6-OHDA; these protective properties were accompanied by antiapoptotic features. According to the findings, it seems that hydromethanolic C. aurantium extract can be used to prevent seizures.

La enfermedad de Parkinson (EP) se describe como una afección neurológica que resulta de la degeneración continua de las neuronas dopaminérgicas. Actualmente, la mayoría de los tratamientos para las enfermedades neurodegenerativas son paliativos. En la medicina tradicional iraní, el extracto de flor de Citrus aurantium se usa para tratar algunas enfermedades neurológicas, como los trastornos del sueño y la ansiedad. La tendencia hacia el uso de las medicinas para el tratamiento de enfermedades (por ejemplo, convulsiones) está creciendo. Por consiguiente, el objetivo de este trabajo consistió en evaluar los efectos antioxidantes de las flores de C. aurantium y analizar sus efectos protectores contra el estrés oxidativo mediado por la 6- hidroxidopamina (6-OHDA). En este estudio, se usó 150 mM de 6-OHDA para inducir daño celular. Además, se realizó un ensayo de MTT para analizar la viabilidad celular. La espectrofotometría de fluorescencia se realizó para medir las especies reactivas de oxígeno (ROS) intracelulares y los niveles de calcio. En base a los hallazgos, 6-OHDA podría reducir la viabilidad celular. También analizamos los efectos de C. aurantium contra la neurotoxicidad. Los niveles intracelulares de ROS y calcio se expandieron a las células expuestas a 6-OHDA. La incubación de células SH-SY5Y con C. aurantium (400 y 600 mg / ml) indujo efectos protectores y disminuyó los marcadores bioquímicos de la apoptosis celular. De acuerdo con los hallazgos, C. aurantium mostró efectos protectores contra la neurotoxicidad, causada por 6-OHDA; estas propiedades protectoras fueron acompañadas por características antiapoptóticas. Según los hallazgos, parece que el extracto hidrometanólico de C. aurantium se puede usar para prevenir las convulsiones.

Chronic treatment with carvacrol improves passive avoidance memory in a rat model of Parkinson's disease / O tratamento com carvacrol melhora a memória de esquiva passiva em um modelo da doença de Parkinson em ratos

ABSTRACT The present study investigated the effects of carvacrol on motor and memory deficits as well as hyperalgesia in the 6-OHDA-lesioned rat model of Parkinson's disease. The animals were subjected to unilateral microinjection of 6-OHDA into the medial forebrain bundle and treated with carvacrol (25, 50 and 100 mg/kg, ip) for six weeks after surgery. The 6-OHDA-lesioned rats showed contralateral rotations towards the lesion side, which was accompanied by learning and memory deficits in a passive avoidance test and a decrease in tail withdrawal latency in a tail flick test at the end of week 6. The results also showed that treatment with carvacrol at a dose of 25 mg/kg ameliorated memory deficits, with no effect on rotations and hyperalgesia in lesioned rats. In conclusion, carvacrol improves memory impairments in rats with Parkinson's disease; therefore, it may serve as an adjunct therapy for the alleviation of memory deficits in Parkinson's disease patients.

RESUMO O presente estudo investigou os efeitos do carvacrol nos déficits motores e de memória, bem como na hiperalgesia, em um modelo da doença de Parkinson (DP) em ratos com lesões 6-OHDA. Os animais foram submetidos a microinjeção unilateral de 6-OHDA no feixe mediano do prosencéfalo e tratados com carvacrol (25, 50 e 100 mg / kg, ip) durante 6 semanas após a cirurgia. Os ratos com lesões 6-OHDA mostraram rotações contralaterais para o lado da lesão, que foram acompanhadas de déficits de aprendizagem e de memória em um teste de evitação passiva, e de uma diminuição da latência de retirada da cauda em um teste de cauda no final da semana 6. Os resultados também mostraram que o tratamento crônico com carvacrol a uma dose de 25 mg / kg aliviou os déficits de memória, sem efeito sobre rotações e hiperalgesia em ratos lesados. Em conclusão, o carvacrol melhora a deficiência de memória em ratos com DP e, portanto, pode servir como uma terapia complementar para aliviar os déficits de memória em pacientes com DP.

Moutan Cortex Radicis inhibits the nigrostriatal damage in a 6-OHDA-induced Parkinson's disease model / 中国天然药物

The traditionally used oriental herbal medicine Moutan Cortex Radicis [MCR; Paeonia Suffruticosa Andrews (Paeoniaceae)] exerts anti-inflammatory, anti-spasmodic, and analgesic effects. In the present study, we investigated the therapeutic effects of differently fractioned MCR extracts in a 6-hydroxydopamine (OHDA)-induced Parkinson's disease model and neuro-blastoma B65 cells. Ethanol-extracted MCR was fractionated by n-hexane, butanol, and distilled water. Adult Sprague-Dawley rats were treated first with 20 μg of 6-OHDA, followed by three MCR extract fractions (100 or 200 mg·kg) for 14 consecutive days. In the behavioral rotation experiment, the MCR extract-treated groups showed significantly decreased number of net turns compared with the 6-OHDA control group. The three fractions also significantly inhibited the reduction in tyrosine hydroxylase-positive cells in the substantia nigra pars compacta following 6-OHDA neurotoxicity. Western blotting analysis revealed significantly reduced tyrosine hydroxylase expression in the substantia nigra pars compacta in the 6-OHDA-treated group, which was significantly inhibited by the n-hexane or distilled water fractions of MCR. B65 cells were exposed to the extract fractions for 24 h prior to addition of 6-OHDA for 30 min; treatment with n-hexane or distilled water fractions of MCR reduced apoptotic cell death induced by 6-OHDA neurotoxicity and inhibited nitric oxide production and neuronal nitric oxide synthase expression. These results showed that n-hexane- and distilled water-fractioned MCR extracts inhibited 6-OHDA-induced neurotoxicity by suppressing nitric oxide production and neuronal nitric oxide synthase activity, suggesting that MCR extracts could serve as a novel candidate treatment for the patients with Parkinson's disease.

Research progress on animal models of Parkinson's disease / 中国比较医学杂志

Parkinson's disease(PD)is a progressive neurodegenerative disorder, with an etiology that is now considered to be due to interaction between genetic and environmental factors. Typical PD features include loss of dopaminergic neurons in the nigrostriatal region, with typical motor traits of PD associated with dopamine deficiency. Animal models have contributed to determining PD etiology and pathogenesis,as well as testing new therapeutic schedules and novel drug research. Rodents, tree shrews, primates, and other animal models of PD have been established by different method. These models each have their own advantages and limitations, showing different clinical features and pathological mechanisms to those in humans. Therefore, the appropriate model for scientific research must be carefully considered. This article reviews the main neurotoxic and transgenic models of PD.

Moutan Cortex Radicis inhibits the nigrostriatal damage in a 6-OHDA-induced Parkinson's disease model / 中国天然药物

The traditionally used oriental herbal medicine Moutan Cortex Radicis [MCR; Paeonia Suffruticosa Andrews (Paeoniaceae)] exerts anti-inflammatory, anti-spasmodic, and analgesic effects. In the present study, we investigated the therapeutic effects of differently fractioned MCR extracts in a 6-hydroxydopamine (OHDA)-induced Parkinson's disease model and neuro-blastoma B65 cells. Ethanol-extracted MCR was fractionated by n-hexane, butanol, and distilled water. Adult Sprague-Dawley rats were treated first with 20 μg of 6-OHDA, followed by three MCR extract fractions (100 or 200 mg·kg) for 14 consecutive days. In the behavioral rotation experiment, the MCR extract-treated groups showed significantly decreased number of net turns compared with the 6-OHDA control group. The three fractions also significantly inhibited the reduction in tyrosine hydroxylase-positive cells in the substantia nigra pars compacta following 6-OHDA neurotoxicity. Western blotting analysis revealed significantly reduced tyrosine hydroxylase expression in the substantia nigra pars compacta in the 6-OHDA-treated group, which was significantly inhibited by the n-hexane or distilled water fractions of MCR. B65 cells were exposed to the extract fractions for 24 h prior to addition of 6-OHDA for 30 min; treatment with n-hexane or distilled water fractions of MCR reduced apoptotic cell death induced by 6-OHDA neurotoxicity and inhibited nitric oxide production and neuronal nitric oxide synthase expression. These results showed that n-hexane- and distilled water-fractioned MCR extracts inhibited 6-OHDA-induced neurotoxicity by suppressing nitric oxide production and neuronal nitric oxide synthase activity, suggesting that MCR extracts could serve as a novel candidate treatment for the patients with Parkinson's disease.

Dimethyl sulfide, a metabolite of the marine microorganism, protects SH-SY5Y cells against 6-hydroxydopamine and MPP+-induced apoptosis / 中国药理学与毒理学杂志

Dimethyl sulfide (DMS) has been historically recognized as a metabolite of the marine microorganism or a disgusting component for the smell of halitosis patients. In our recent study, DMS has been identified as a cytoprotectant that protects against oxidative-stress induced cell death and aging. We found that at near- physiological concentrations, DMS reduced reactive oxygen species (ROS) in cultured PC12 cells and alleviated oxidative stress. The radical-scavenging capacity of DMS at near-physiological concentration was equivalent to endogenous methionine(Met)-centered antioxidant defense. Methionine sulfoxidereductase A (MsrA), the key antioxidant enzyme in Met-centered defense, bound to DMS and promoted its antioxidant capacity via facilitating the reaction of DMS with ROS through a sulfonium intermediate at residues Cys72, Tyr103, Glu115, followed by the release of dimethyl sulfoxide (DMSO). MTT assay and trypan blue test indicated that supplement of DMS exhibited cytopro?tection against 6-hydroxydopamine and MPP + induced cell apoptosis. Furthermore, MsrA knockdown abolished the cytoprotective effect of DMS at near- physiological concentrations. The present study reveals new insight into the potential therapeutic value of DMS in Parkinson disease.

Effect of pinealectomy and gonadectomy on dopaminergic neurons of mesencephalon in Parkinson's disease model rats / 中华行为医学与脑科学杂志

Objective To investigate the effect of PX and GDX on dopaminergic neurons of mesencephalon in Parkinson's disease model rats.Methods Eighty male Wistar rats were randomly divided into five groups:NS,N+6-OHDA,PX+6-OHDA,GDX+6-OHDA and PX+GDX+6-OHDA group;16 rats in each group.60 days after operation,6-OHDA was injected into SNc and VTA in the right side of the mesencephalon.Mter 14 days,the rats were sacrificed.HE staining was used to observe the proliferation of glial cells.The number of astrocytes was observed by GFAP staining.The number of apoptotic cells was observed by TUNEL staining.Immunohistochemical staining (S-P Method) was used to detect the changes of TH-positive cells and fiber,apoptosis-related proteins Bax and Bcl2.Results (1) The numbers of proliferated glial cells in SNc and VTA were significantly increased according to the following sequence:NS,N+6-OHDA,PX + 6-OHDA,GDX+ 6-OHDA,and PX+GDX+6-OHDA (HE staining:Hc =280.178,P＜0.01;Hc =334.260,P＜0.01) (GFAP staining:Hc=367.081,P＜0.01;Hc=376.049,P＜0.01).(2) The numbers of apoptotic cells in SNc and VTA were significantly increased according to the following sequence:NS,N+ 6-OHDA,PX+ 6-OHDA,GDX+6-OHDA,and PX+GDX+6-OHDA (Hc =344.401,P＜0.01;Hc =326.198,P＜0.01).(3) The numbers of TH (+) cells in SNc and VTA were significantly decreased according to the following sequence:NS,N+6-OHDA,PX+ 6-OHDA,GDX+ 6-OHDA,and PX+GDX+ 6-OHDA (Hc =366.532,P＜ 0.01;Hc =372.565,P＜0.01).(4) The gray values of TH(+) positive cells and fiber in SNc and VTA were significantly increased according to the following sequence:NS,N+6-OHDA,PX+6-OHDA,GDX+6-OHDA and PX+GDX+ 6-OHDA (F=517.239,P＜ 0.01;F=526.758,P＜ 0.01).(5) Bax expression:weakly positive in NS group,positive in N+6-OHDA group,and strongly positive in remaining three groups;Bcl2 expression:weakly positive in each group.Conclusion PX and GDX significantly aggravate neurotoxicity of 6-OHDA.And GDX is greater than PX,while PX + GDX is strongest.

Changes of ionized calcium binding adapter molecule 1 and pro-opiome-lanocortin expression in arcuate nucleus of hypothalamus induced by substantia nigra lesion with 6-hydroxydopamine / 中国病理生理杂志

AIM:To observe the expression of tyrosine hydroxylase (TH), ionized calcium binding adapter molecule 1 (Iba1) and pro-opiomelanocortin (POMC) in rat arcuate nucleus (Arc) of hypothalamus induced by substantia nigra (SN) lesion with 6-hydroxydopamine (6-OHDA).METHODS:According to the random number table, 20 SD rats were randomly divided into 6-OHDA group and control group.6-OHDA was injected into the bilateral SN of the rats in 6-OHDA group, and the same volume of saline was injected into the same position of the rats in control group.After 6 weeks, the rats were sacrificed and the brains were obtained.Immunofluorescence staining and Western blot were used to detect TH expression in the SN, and TH, Iba1 and POMC expression in the Arc.RESULTS:Compared with control group, no significant change of body weight in 6-OHDA group was observed, but the weight of retroperitoneal fat decreased from (7.550±0.670) g to (3.895±0.465) g (P<0.01).The number of TH immunoreactive neurons in SN decreased from 56±5 to 14±2 (P<0.05), and the TH protein level decreased from 0.75±0.11 to 0.41±0.09 (P<0.01).In the Arc, the number of TH immunoreactive neurons decreased from 21±2 to 10±3 (P<0.05), the number of Iba1 immunoreactive neurons increased from 12±2 to 30±5 (P<0.05), and the number of POMC immunoreactive neurons increased from 16±4 to 31±2 (P<0.05).In the hypothalamus, the TH protein level decreased from 0.35±0.05 to 0.21±0.02 (P<0.01), the Iba1 protein level increased from 0.23±0.06 to 0.51±0.04 (P<0.01), and the POMC protein level increased from 0.37±0.05 to 0.65±0.03 (P<0.01).CONCLUSION:The changes of TH, Iba1 and POMC expression in Arc of 6-OHDA-treated rats may involved in the fat loss in Parkinson's disease.

Protective Effects of Zhen-Gan Xi-Feng Decoction-containing Serum on 6-OHDA-induced Oxidative Stress in PC12 Cells through Nrf2-ARE Pathway Activation / 世界科学技术-中医药现代化

This paper was aimed to study the protective effects and related mechanisms of Zhen-Gan Xi-Feng (ZGXF) decoction containing serum on 6-OHDA-induced oxidative stress in PC12 cells.The ZGXF decoction containing rat serum with low-,medium-,and high-dose (8,16,or 32 g.kg-1) or blank serum was used to preprocess PC12 cells for 1 h,and cultured together with 100 μM 6-OHDA for 24 h.And then,cells were collected.The fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH-DA) and fluorescence microplate reader were used to detect the level of reactive oxygen species (ROS).Real-time quantitative PCR was used to analyze the mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2),Nfe2l2,heme oxygenase-1 (HO-1),glutamate-cysteine ligase catalytic subunit (GCLc),and GCL modulatory subunit (GCLm).The luciferase report gene system was used to detect the antioxidant response element (ARE) activation.The results showed that ZGXF decoction-containing serum inhibited the 6-OHDA-induced oxidative stress,upregulated the Nfe2l2,HO-1 and GCLc mRNA expressions in cells processed with 6-OHDA.However,it has no significant effect on GCLm mRNA expression.It was concluded that ZGXF decoction-containing serum had protective effects on 6-OHDA-induced oxidative stress in PC 12 cells.Its mechanism may be correlated with the upregulation on Nfe2l2 mRNA expression,which activated ARE and further induced its downstream gene of phase Ⅱ detoxifying enzyme,as well as the HO-1 and GCLc mRNA expressions of antioxidant enzyme gene.

Effect of pinealectomy and gonadectomy on dopaminergic neurons of mesencephalon in Parkinson's disease model rats / 中华行为医学与脑科学杂志

Objective To investigate the effect of PX and GDX on dopaminergic neurons of mesencephalon in Parkinson's disease model rats.Methods Eighty male Wistar rats were randomly divided into five groups:NS,N+6-OHDA,PX+6-OHDA,GDX+6-OHDA and PX+GDX+6-OHDA group;16 rats in each group.60 days after operation,6-OHDA was injected into SNc and VTA in the right side of the mesencephalon.Mter 14 days,the rats were sacrificed.HE staining was used to observe the proliferation of glial cells.The number of astrocytes was observed by GFAP staining.The number of apoptotic cells was observed by TUNEL staining.Immunohistochemical staining (S-P Method) was used to detect the changes of TH-positive cells and fiber,apoptosis-related proteins Bax and Bcl2.Results (1) The numbers of proliferated glial cells in SNc and VTA were significantly increased according to the following sequence:NS,N+6-OHDA,PX + 6-OHDA,GDX+ 6-OHDA,and PX+GDX+6-OHDA (HE staining:Hc =280.178,P＜0.01;Hc =334.260,P＜0.01) (GFAP staining:Hc=367.081,P＜0.01;Hc=376.049,P＜0.01).(2) The numbers of apoptotic cells in SNc and VTA were significantly increased according to the following sequence:NS,N+ 6-OHDA,PX+ 6-OHDA,GDX+6-OHDA,and PX+GDX+6-OHDA (Hc =344.401,P＜0.01;Hc =326.198,P＜0.01).(3) The numbers of TH (+) cells in SNc and VTA were significantly decreased according to the following sequence:NS,N+6-OHDA,PX+ 6-OHDA,GDX+ 6-OHDA,and PX+GDX+ 6-OHDA (Hc =366.532,P＜ 0.01;Hc =372.565,P＜0.01).(4) The gray values of TH(+) positive cells and fiber in SNc and VTA were significantly increased according to the following sequence:NS,N+6-OHDA,PX+6-OHDA,GDX+6-OHDA and PX+GDX+ 6-OHDA (F=517.239,P＜ 0.01;F=526.758,P＜ 0.01).(5) Bax expression:weakly positive in NS group,positive in N+6-OHDA group,and strongly positive in remaining three groups;Bcl2 expression:weakly positive in each group.Conclusion PX and GDX significantly aggravate neurotoxicity of 6-OHDA.And GDX is greater than PX,while PX + GDX is strongest.

Fucoidan attenuates 6-hydroxydopamine-induced neurotoxicity by exerting anti-oxidative and anti-apoptotic actions in SH-SY5Y cells

Parkinson's disease (PD) is an irreversible neurological disorder with related locomotor dysfunction and is haracterized by the selective loss of nigral neurons. PD can be experimentally induced by 6-hydroxydopamine (6-OHDA). It has been reported that reactive oxygen species, which deplete endogenous glutathione (GSH) levels, may play important roles in the dopaminergic cell death characteristic of PD. Fucoidan, a sulfated algal polysaccharide, exhibits anti-inflammatory and anti-oxidant actions. In this study, we investigated whether fucoidan can protect against 6-OHDA-mediated cytotoxicity in SH-SY5Y cells. Cytotoxicity was evaluated by using MTT and LDH assays. Fucoidan alleviated cell damage evoked by 6-OHDA dose-dependently. Fucoidan reduced the number of apoptotic nuclei and the extent of annexin-V-associated apoptosis, as revealed by DAPI staining and flow cytometry. Elevation of lipid peroxidation and caspase-3/7 activities induced by 6-OHDA was attenuated by fucoidan, which also protected against cytotoxicity evoked by buthionine-sulfoximine-mediated GSH depletion. Reduction in the glutathione/glutathione disulfide ratio induced by 6-OHDA was reversed by fucoidan, which also inhibited 6-OHDA-induced disruption of mitochondrial membrane potential. The results indicate that fucoidan may have protective action against 6-OHDA-mediated neurotoxicity by modulating oxidative injury and apoptosis through GSH depletion.

Effects of crocin on brain oxidative damage and aversive memory in a 6-OHDA model of Parkinson's disease / Efeitos da crocina no dano oxidativo cerebral e na memória aversiva em um modelo 6-OHDA de doença de Parkinson

ABSTRACT The purpose of the present study was to investigate the effect of crocin on brain oxidative damage and memory deficits in a 6-hydroxydopamine (6-OHDA) model of Parkinson’s disease. Male Wistar rats were subjected to unilateral injection of 6-OHDA (16 µg) into the medial forebrain bundle and treated with crocin (30 and 60 mg/kg) for six weeks. The rats were tested for memory performance at six weeks after 6-OHDA infusion, and then were killed for the estimation of biochemical parameters. The increase in thiobarbituric acid reactive substances (TBARS) and nitrite levels in the hippocampus were observed in the 6-OHDA lesioned rats, which was accompanied by memory deficits in a passive avoidance test at the end of week 6. Moreover, treatment with crocin decreased TBARS and nitrite levels in the hippocampus, and improved aversive memory. The present study conclusively demonstrated that crocin acts as an antioxidant and anti-inflammatory agent in the hippocampus of parkinsonian rats and could improve aversive memory through its properties.

RESUMO O objetivo do presente estudo foi investigar o efeito da crocina no dano oxidativo cerebral e nos déficits de memória em um modelo 6-OHDA de doença de Parkinson. Ratos Wistar machos foram submetidos à injeção unilateral de 6-OHDA (16 μg) em MFB e tratados com crocina (30 e 60 mg/kg), durante 6 semanas. Os ratos foram testados quanto ao desempenho da memória 6 semanas após a infusão de 6-OHDA, e, em seguida, foram sacrificados para a estimativa dos parâmetros bioquímicos. O aumento nos níveis de TBARS e de nitrito no hipocampo foram observados em ratos 6-OHDA lesionados, acompanhado por déficits de memória em um teste de esquiva passiva no final da semana 6. Além disso, o tratamento com crocina diminuiu os níveis de nitrito e de TBARS no hipocampo e melhorou a memória aversiva. O presente estudo demonstrou conclusivamente que a crocina age como um antioxidante e um agente anti-inflamatório no hipocampo de ratos parkinsonianos e pode melhorar a memória aversiva através de suas propriedades.

Antioxidant Activity of Oral Administration of Rosmarinus Officinalis Leaves Extract on Rat's Hippocampus which Exposed to 6-Hydroxydopamine

Carnosic acid, a diterpene of Rosemarinus officinalis leaves extract (RE), has potent antioxidant activity in vitro. The dopaminergic connection of substantia nigra pars compacta to the hippocampus might be affected by oxidative stress which caused cognitive impairment observed in the early phase of Parkinson's disease (PD). Adult male Wistar rats were lesioned bilaterally by intra-nigral injection of 6-OHDA, and divided into six groups: four groups that orally given RE containing 40% of carnosic acid, at doses of 25, 50 and 100 mg/kg (treated rats) and distilled water (H2O), once daily for a period of 14 days before and after the injury. There were also two another groups as control rats which injected by normal saline and untreated lesion group. The injured animals were evaluated for their spatial memory performance by Morris Water Maze test. Lesioned rats showed significant increase in escape latency, as compared with control group. Two weeks after injury, tissue samples were collected from the hippocampus. Levels of catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase (SOD), malondialdehyde (MDA) and reactive oxygen species (ROS) were determined. There were significant increase of SOD, GPX and CAT enzymes activities in RE50 treated group as compared to lesioned rats. We found a significant decrease of ROS in RE50 treated group as compared to Lesioned rats. These findings provide evidence that 50 mg/kg of RE decreased oxidative damage of the hippocampus induced by 6-OHDA and serve as potential candidate for the treatment of PD.

The Effects of Crocin on 6-OHDA-Induced Oxidative/Nitrosative Damage and Motor Behaviour in Hemiparkinsonian Rats

Background: Crocin is considered to prevent oxidative stress-related diseases, such as ischemia and Alzheimer's. The aim of the present investigation was to evaluate the effects of crocin on motor behaviour and 6-OHDA-induced oxidative/nitrosative damage to the striatum in an experimental model of Parkinson's disease. Methods: Left medial forebrain bundle was lesioned by microinjection of 6-OHDA (16μg in 0.2% ascorbate-saline). Crocin (30 and 60 mg/kg) was injected intraperitoneally three days before surgery until six weeks. Rotational behaviour and biochemical analysis were used to evaluate the effect of crocin in a unilateral 6-OHDA-induced model of Parkinson's disease. Results: The contralateral rotations induced by apomorphine in 6-OHDA lesioned group were highly significant (P < 0.001) as compared to the sham group. Moreover, chronic administration of crocin at doses of 30 and 60 mg/kg over six weeks did not change the rotations. The TBARS and nitrite levels in the striatum were also significantly (P < 0.05) increased in lesioned group. Treatment with crocin at a dose of 60 mg/kg significantly decreased the nitrite levels (P < 0.05) in the striatum. Conclusion: Crocin at a dose of 60 mg/kg could be effective in preventing the nitrosative damage in the striatum. Further investigations using higher doses of crocin is suggested to get the full neuroprotective effects of crocin in Parkinson's disease.

Effects of Gypenosides on Dopaminergic Neuronal Cell Death in 6-Hydroxydopamine-lesioned Rat Model of Parkinson's Disease with Long-term L-DOPA Treatment

The goal of this study was to determine whether gypenosides (GPS) exert protective effects against dopaminergic neuronal cell death in a 6-hydroxydopamine (OHDA)-lesioned rat model of Parkinson's disease (PD) with or without long-term 3,4-dihydroxyphenylalanine (L-DOPA) treatment. Rats were injected with 6-OHDA in the substantia nigra to induce PD-like symptoms; 14 days after injection, groups of 6-OHDA-lesioned animals were treated for 21 days with GPS (25 or 50 mg/kg) and/or L-DOPA (20 mg/kg). Dopaminergic neuronal cell death was assessed by counting tyrosine hydroxylase (TH)-immunopositive cells in the substantia nigra and measuring levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the striatum. Dopaminergic neuronal cell death induced by 6-OHDA lesions was ameliorated by GPS treatment (50 mg/kg). L-DOPA treatment exacerbated 6-OHDA-induced dopaminergic neuronal cell death; however, these effects were partially reversed by GPS treatment (25 and 50 mg/kg). These results suggest that GPS treatment is protective against dopaminergic neuronal cell death in a 6-OHDA-lesioned rat model of PD with long-term L-DOPA treatment. Therefore, GPS may be useful as a phytotherapeutic agent for the treatment of PD.