C-phycocyanin shows neuroprotective effect against rotenone-induced Parkinson’s disease in mice

Objective:To investigate the neuroprotective effect of C-phycocyanin in a mouse model of rotenone-induced Parkinson’s disease.Methods:C-phycocyanin(50 mg/kg,i.p.,daily)was administered to rotenone(30 mg/kg,p.o.,daily)treated mice for 28 days.Behavioral studies(Y-maze,rotarod,round beam walk,and wire-hang tests)were carried out to assess neurobehavioral deficits.Glutathione and malondialdehyde were determined in both serum and striatal tissue.Molecular proteins(AKT,AMPK,NF-κB,BDNF,and alpha-synuclein)in the striatum were estimated using ELISA.Histopathological analyses(hematoxylin and eosin stainning as well as Nissl staining)were carried out to assess structural abnormalities in the striatum.Results:C-phycocyanin significantly increased BDNF levels and decreased alpha-synuclein levels.It also slightly upregulated AMPK and AKT levels without significant difference compared with the rotenone group.Additionally,rotenone-induced elevated oxidative stress and structural abnormalities in the striatum were markedly mitigated by C-phycocyanin.Conclusions:C-phycocyanin might have potential neuroprotective effects against Parkinson’s disease.Further studies are warranted to verify its efficacy and to understand the molecular mechanisms behind the neuroprotective effects of C-phycocyanin in Parkinson’s disease.

α-Synuclein redistributed and aggregated in rotenone-induced Parkinson’s disease rats

Objective To observe the influence of rotenone on the distribution of α-synuclein （ASN） in rat model of Parkinson＇s disease （PD）. Methods Wistar rats were randomly divided into two groups and received 2 mg/kg rotenone （s.c.） or sunflower oil （as control group） for about 4 weeks. The hippocampus, substantia nigra and striatum of brain were observed. Hematoxylin and eosin stain were used to observe the Lewy body like inclusion. The expression of tyrosine hydroxylase （TH） or ASN protein was determined by anti-TH or anti-α-synuclein immunohistochemistry, respectively. Results In control rats, ASN protein distributed widely in brain, especially in hippocampus, cortex and striatum. Rotenone obviously increased TH positive neurons and fibers loss in substantia nigra and striatum （P 〈 0.05）. In rotenone treated rats, ASN positive cells increased in global brain but not distributed in an even manner. In substantia nigra, ASN positive stuff was found aggregate in both cytoplasm and nucleus, and some formed spherical inclusion; in striatum, ASN positive neurites end aggregated and agglomerated around neurons; and in hippocampus, few dot-like ASN were aggregated in cell body, and no notable change was found in nucleus. Conclusion In rotenone administrated PD rats, ASN protein aggregated in several brain regions but most obviously in striatum and substantia nigra, and the distribution region of ASN was changed from peri-synapse to the cytoplasm and nucleus of dopaminergic neuron.

Gastrodin inhibits neuroinflammation in rotenone-induced Parkinson's disease model rats

The present study showed that the latency of rats moving on a vertical grid was significantly prolonged, and the number of rats sliding down from the declined plane was increased remarkably, in rotenone-induced Parkinson＇s disease model rats compared with control rats. The moving latency recovered to normal levels, but the number of slides was significantly increased at 28 days after model establishment. The slope test is a meaningful approach to evaluate the symptoms of Parkinson＇s disease model rats treated with rotenone. In addition, loss of substantia nigral dopaminergic neurons in model rats was observed at 1 day after the model was established, and continued gradually at 14 and 28 days. The expression of tyrosine hydroxylase-positive cells was significantly increased in gastrodin-treated rats at 14 days. Significant numbers of activated microglia cells were observed in model rats at 14 and 28 days; treatment of rats with Madopar at 28 days suppressed microglial activation. Treatment of rats with gastrodin or Madopar at 28 days significantly reduced interleukin-1β expression. The loss of substantia nigral dopaminergic neurons paralleled the microglial activation in Parkinson＇s disease model rats treated with rotenone. The inflammatory factors tumor necrosis factor-a and interleukin-1β are involved in the substantia nigral damage. Gastrodin could protect dopaminergic neurons via inhibition of interteukin-1β expression and neuroinflammation in the substantia nigra.

Comparsion of the Effects of Succinate and NADH on Postmortem Metmyoglobin Redcutase Activity and Beef Colour Stability

In two experiments, the effects of succinate and NADH（reduced nicotinamide adenine dinucleotide） on metmyoglobin reductase activity and electron transport chain-linked metmyoglobin reduction were investigated and compared. In experiment 1, metmyoglobin（MetMb）, substrate and inhibitors were incubated with mitochondria. Comparsion of the effects of succinate and NADH on MetMb reduction was investigated. The MetMb percentage in sample treated with 8 mol L-1 succinate decreased by about 69% after 3 h incubation, and the effect was inhibited by the addition of 10 mol L-1 electron transfer chain complex II inhibitor malonic acid; the MetMb percentage in samples treated with 2 mol L-1 NADH decreased by 56% and the effect was inhibited by the addition of 0.02 mol L-1 electron transport chain complex I inhibitor rotenone. These results indicated that electron transport chain played an important role in MetMb reduction. Both complex II and complex I take part in the MetMb reduction in mitochondria through different pathways. NADH-MetMb reduction system was less stable than succinateMetMb system. In experiment 2, the beef longissimus dorsi muscle was blended with different concentrations of succinate or NADH. Enhancing patties with higher concentration of succinate or NADH improved colour stability in vacuum packaged samples（P〈0.05）. These results verified that mitochondria electron transport chain is related to the MetMb reduction in meat system.

H_2O_2预处理抑制α-Synuclein的聚集并减轻Rotenone对PC12细胞的损伤

目的探讨H2O2预处理(HPP)对Rotenone诱导PC12细胞损伤及α-Synuclein聚集的影响。方法采用四甲基偶氮唑盐法(MTT法)、流式细胞仪、免疫印迹(western blot)技术及共聚焦显微镜分别检测细胞活力、细胞凋亡率、α-Synuclein的表达及聚集。结果H2O2预处理能够减少α-Synuclein寡聚体的表达及聚集体的形成,增加PC12细胞活力(Rot组47%±3.67%,HPP+Rot组82%±6.69%),抑制细胞凋亡(Rot组49.68%±4.55%,HPP+Rot组18.73%±5.64%)。结论H2O2预处理能减轻Rotenone对PC12细胞的毒性损伤作用,这种保护作用可能是通过抑制α-Synuclein寡聚体表达实现的。

Neurotoxicity of the pesticide rotenone on neuronal polarization: a mechanistic approach

Neurons are the most extensive and polarized cells that display a unique single long axon and multiple dendrites, which are compartments exhibiting structural and functional differences. Polarity occurs early in neuronal development and it is maintained by complex subcellular mechanisms throughout cell life. A well-defined and controlled spatio-temporal program of cellular and molecular events strictly regulates the formation of the axon and dendrites from a non-polarized cell. This event is critical for an adequate neuronal wiring and therefore for the normal functioning of the nervous system. Neuronal polarity is very sensitive to the harmful effects of different factors present in the environment. In this regard, rotenone is a crystalline, colorless and odorless isoflavone used as insecticide, piscicide and broad spectrum pesticide commonly used earlier in agriculture. In the present review we will summarize the toxicity mechanism caused by this pesticide in different neuronal cell types, focusing on a particular biological mechanism whereby rotenone could impair neuronal polarization in cultured hippocampal neurons. Recent advances suggest that the inhibition of axonogenesis produced by rotenone could be related with its effect on microtubule dynamics, the actin cytoskeleton and their regulatory pathways, particularly affecting the small RhoGTPase RhoA. Unveiling the mechanism by which rotenone produces neurotoxicity will be instrumental to understand the cellular mechanisms involved in neurodegenerative diseases influenced by this environmental pollutant, which may lead to research focused on the design of new therapeutic strategies.

Effect of moxibustion on mTOR-mediated autophagy in rotenone-induced Parkinson's disease model rats

Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson’s disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin （mTOR）, with subsequent elimination of α-syn. A Parkinson’s disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli （ST36）, Guanyuan （CV4）and Fengfu （GV16）, for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson’s disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-II protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity,the expression of phosphorylated mTOR and phosphorylated ribosomal protein S6 kinase （p-p70S6K） in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson’s disease model rats. The protective mechanism may be associated with suppression of the mTOR/p70S6K pathway.

Divalent metal transporter 1 expression and iron deposition in the substantia nigra of a rat model of Parkinson's disease

Extensive iron deposition has been observed in the midbrain substantia nigra （SN） of Parkinson＇s disease （PD） patients, but the mechanisms of iron deposition in the SN remain poorly understood. The present study investigated the relationship between dopaminergic neuronal damage, iron content changes, and divalent metal transporter 1 （DMT1） in the midbrain SN of PD rats to explore the relationship between time of iron deposition and DMT1 expression. Frozen midbrain SN sections from model rats were stained with Perls＇ iron. Results showed massive loss of tyrosine hydroxylase （TH）-positive cells in the SN and increased DMT1 expression in model group rats. No obvious iron deposition was observed in the SN during early stages after damage, but significant iron deposition was detected at 8 weeks post-injury. Results demonstrate that the loss of TH-positive cells in the SN appeared simultaneously with increased DMT1 expression. Extensive iron deposition occurred at 8 weeks post injury, which could be regarded as an early time window of iron deposition.

Baicalin and deferoxamine alleviate iron accumulation in different brain regions of Parkinson's disease rats

Previous studies found that iron accumulates in the substantia nigra of Parkinson＇s disease patients However, it is still unclear whether other brain regions have iron accumulation as well. In this experiment, rats with rotenone-induced Parkinson＇s disease were treated by gastric perfusion of baicalin or intraperitoneal injection of deferoxamine. Immunohistochemical staining demonstrated that iron accumulated not only in the substantia nigra pars compacta, but also significantly in the striatum globus pallidus, the dentate gyrus granular layer of the hippocampus, the dentate-interpositus and the facial nucleus of the cerebellum. Both baicalin and deferoxamine, which are iron chelating agents, significantly inhibited iron deposition in these brain areas, and substantially reduced the loss of tyrosine hydroxylase-positive cells. These chelators also reduced iron content in the substantia nigra. In addition to the substantia nigra, iron deposition was observed in other brain regions as well. Both baicalin and deferoxamine significantly inhibited iron accumulation in different brain regions, and had a protective effect on dopaminergic neurons.

Parallel relationship between microglial activation and substantia nigra damage in a rotenone-induced Parkinson's disease rat model

BACKGROUND： Inflammatory injury induced by microglial activation plays an important role in the occurrence and development of Parkinson＇s disease （PD）. However, few studies have examined the relationship between microglia and substantia nigra damage or dopaminergic neuron loss in animals with rotenone-induced PD.OBJECTIVE： To explore the relationship between activated microglia and loss of the substantia nigra, and the changes in concentration and dose of rotenone in the brain of rats with rotenone-induced PD.DESIGN, TIME AND SETTING： The neuropathological experiment was performed at the School of Traditional Chinese Medicine, Capital Medical University, China, from July 2007 to July 2008. MATERIALS： Rotenone was purchased from Sigma, USA. METHODS： The Parkinson＇s model was induced by injection of a rotenone oily-emulsion （2 mg/kg daily） subcutaneously into the back of 58 male adult Wistar rats for 3-6 weeks. Another three rats served as normal controls.MAIN OUTCOME MEASURES： Neurobehavioral changes were observed and recorded following rotenone treatment. Tyrosine hydroxylase and complement receptor OX42 were separately analyzed by immunohistochemical staining within 4 weeks following stopping rotenone treatment. Rotenone content was measured using high performance liquid chromatography in the cerebellum of rats that scored 2.4-6.RESULTS： Rotenone induced a loss of dopaminergic neurons in the substantia nigra as well as microglial activation, with increased behavior scores. Dopaminergic loss was still ongoing even when rotenone was stopped. Dopaminergic neuronal degeneration in the substantia nigra was initially 6%, but was 85% at 2 weeks after scoring, and degeneration depended on activated microglia. Rotenone was detected in the cerebellum at concentrations between 78.9 μg/L and 309.6 μg/L. CONCLUSION： Nigrostriatal dopaminergic degeneration paralleled the microglial activation. Rotenone absorbed into the brain in its original form initiated pathological injury in the substantia niara of PD rats.

Neuroprotective role of(Val^8)GLP-1-Glu-PAL in an in vitro model of Parkinson's disease

The growth factor glucagon-like peptide-1（GLP-1） is neuroprotective in several animal models of neurodegeneration. Here, we analyzed the neuroprotective effects of a novel protease-resistant GLP-1 analogue,（Val^8）GLP-1-Glu-PAL, which has advantages over older analogues, such as improvement of hippocampal neurogenesis, glucose homeostasis, and insulin secretion. We established an in vitro model of Parkinson＇s disease using the mitochondrial stressor rotenone in primary cultured mouse neurons pretreated with（Val^8）GLP-1-Glu-PAL.（Val^8）GLP-1-Glu-PAL alone did not affect neuronal viability, but prevented the rotenone-induced reduction in cell viability in a dose-dependent manner. In addition,（Val^8）GLP-1-Glu-PAL pretreatment prevented rotenone-induced proapoptotic changes manifesting as downregulation of procaspase-3 and Bcl-2 and upregulation of cleaved caspase-3. These results demonstrate that the novel agent（Val^8）GLP-1-GluPAL shows promise as a drug treatment for Parkinson＇s disease.

Updates in the pathophysiological mechanisms of Parkinson's disease: Emerging role of bone marrow mesenchymal stem cells

AIM: To explore the approaches exerted by mesenchymal stem cells (MSCs) to improve Parkinson’s disease (PD) pathophysiology.METHODS: MSCs were harvested from bone marrow of femoral bones of male rats, grown and propagated in culture. Twenty four ovariectomized animals were classified into 3 groups: Group (1) was control, Groups (2) and (3) were subcutaneously administered with rotenone for 14 d after one month of ovariectomy for induction of PD. Then, Group (2) was left untreated, while Group (3) was treated with single intravenous dose of bone marrow derived MSCs (BM-MSCs). SRY gene was assessed by PCR in brain tissue of the female rats. Serum transforming growth factor beta-1 (TGF-β1), monocyte chemoattractant protein-1 (MCP-1) and brain derived neurotrophic factor (BDNF) levels were assayed by ELISA. Brain dopamine DA level was assayed fluorometrically, while brain tyrosine hydroxylase (TH) and nestin gene expression were detected by semi-quantitative real time PCR. Brain survivin expression was determined by immunohistochemical procedure. Histopathological investigation of brain tissues was also done.RESULTS: BM-MSCs were able to home at the injured brains and elicited significant decrease in serum TGF-β1 (489.7 ± 13.0 vs 691.2 ± 8.0, P < 0.05) and MCP-1 (89.6 ± 2.0 vs 112.1 ± 1.9, P < 0.05) levels associated with significant increase in serum BDNF (3663 ± 17.8 vs 2905 ± 72.9, P < 0.05) and brain DA (874 ± 15.0 vs 599 ± 9.8, P < 0.05) levels as well as brain TH (1.18 ± 0.004 vs 0.54 ± 0.009, P < 0.05) and nestin (1.29 ± 0.005 vs 0.67 ± 0.006, P < 0.05) genes expression levels. In addition to, producing insignificant increase in the number of positive cells for survivin (293.2 ± 15.9 vs 271.5 ± 15.9, P > 0.05) expression. Finally, the brain sections showed intact histological structure of the striatum as a result of treatment with BM-MSCs.CONCLUSION: The current study sheds light on the therapeutic potential of BM-MSCs against PD pathophysiology via multi-mechanistic actions.

Determination of Rotenone Residues in Foodstuffs by Solid-Phase Extraction (SPE) and Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS)

We developed a novel approach to determine rotenone residues in foodstuffs, by integrating solid-phase extraction （SPE） and liquid chromatography/tandem mass spectrometry （LC-MS/MS） technologies, to achieve high sensitivity and selectivity. In our method, the solvent extraction with n-hexane-dichloromethane （50：50, v/v） and cleanup with florisil SPE cartridges using ethyl acetate-ethyl ether （25：75, v/v） as eluents provided adequate recovery of rotenone. The detection of rotenone was then carried out by LC-MS/MS using acetonitrile-water with the 0.1% formic acid （w/v） as the mobile phase. The multiple reaction monitoring （MRM） scheme employed in the approach involved the transitions of the precursor ion to three selected product ions, in which one pair for quantification was m/z 395.3 〉 213.2 and the other two pairs for identification were m/z 395.3 〉 192.2 and 395.3 〉 367.0. The limits of quantification （LOQs） of the method ranged from 0.001 to 0.005 mg kg-1 depending on the matrix. Intra- and inter-day precisions （relative standard deviations, RSDs） for rotenone were less than 7.1 and 14.8%, respectively. Results from repetitive analysis suggested good reproducibility of the method for rotenone residue detection. The recoveries at three concentrations （LOQ, 10LOQ and 100LOQ） ranged from 79.3-118.3% in cabbage, potato, onion, carrot, apple, orange, banana, lichee, tea, and Shiitake mushroom. The proposed procedure was then applied to the analysis of 129 real samples collected from Xiamen, Fujian Province, China. The existence of rotenone was found in two tea products with concentrations of 0.012 and 0.016 mg kg-1, respectively. The method has great potential for routine analysis of monitoring rotenone residue in foodstuffs.

Myricetin reduces cytotoxicity by suppressing hepcidin expression in MES23.5 cells

Multiple studies implicate iron accumulation in the substantia nigra in the degeneration of dopaminergic neurons in Parkinson’s disease.Indeed,slowing of iron accumulation in cells has been identified as the key point for delaying and treating Parkinson’s disease.Myricetin reportedly plays an important role in anti-oxidation,anti-apoptosis,anti-inflammation,and iron chelation.However,the mechanism underlying its neuroprotection remains unclear.In the present study,MES23.5 cells were treated with 1×10^-6 M myricetin for 1 hour,followed by co-treatment with 400 nM rotenone for 24 hours to establish an in vitro cell model of Parkinson’s disease.Our results revealed that myricetin alleviated rotenone-induced decreases in cell viability,suppressed the production of intracellular reactive oxygen species,and restored mitochondrial transmembrane potential.In addition,myricetin significantly suppressed rotenone-induced hepcidin gene transcription and partly relieved rotenone-induced inhibition of ferroportin 1 mRNA and protein levels.Furthermore,myricetin inhibited rotenone-induced phosphorylation of STAT3 and SMAD1 in MES23.5 cells.These findings suggest that myricetin protected rotenone-treated MES23.5 cells by potently inhibiting hepcidin expression to prevent iron accumulation,and this effect was mediated by alteration of STAT3 and SMAD1 signaling pathways.

Effect of rifampicin pre-and post-treatment on rotenone-induced dopaminergic neuronal apoptosis and alpha-synuclein expression

BACKGROUND： Rifampicin inhibits the formation of a-synuclein multimer and protects against 1-methyl-4-phenyl-1,2, 3, 6-tetrahydropyritine （MPTP）-induced PC12 cell apoptosis. OBJECTIVE： To compare the effect of rifampicin pre- and post-treatment on tyrosine hydroxylase and α-synuclein expression in substantia nigra pars compacta in a rat model of Parkinson＇s disease. DESIGN, TIME AND SE＇B＇ING： A randomized, controlled experiment was performed at the Experimental Animal Center of Sun Yat-sen University North Campus （China） from November 2006 to October 2008. MATERIALS： Rifampicin was purchased from MD, USA; rotenone was purchased from Sigma, USA; mouse anti-rat α-synuclein monoclonal antibody was purchased from B＆D, USA; and rabbit anti-rat tyrosine hydroxylase monoclonal antibody was purchased from Chemicon, USA. METHODS： A total of 72 male, Sprague Dawley rats, aged 8 weeks, were randomly assigned to 5 groups： blank control （n = 12）, rifampicin （n = 12）, rotenone （n = 16）, rifampicin pre-treatment （n = 16）, and rifampicin post-treatment （n = 16）. Parkinson＇s disease model rats were established via a subcutaneous injection of rotenone （1.5 mg/kg per day） in the three treatment groups, once a day for 3 successive weeks. Rifampicin （30 mg/kg per day） was intragastrically administered in the rifampicin pre-treatment group 3 days prior to rotenone induction and in the rifampicin post-treatment group 7 days after rotenone induction. Rats were treated with a subcutaneous injection of 1 mL/kg per day sunflower oil in the blank control group and an intragastric injection of 30 mg/kg per day rifampicin in the rifampicin group, once a day for 3 successive weeks in total. MAIN OUTCOME MEASURES： Prior to treatment and in the end of the 3^rd week after treatment, the rats were evaluated using the modified neurological severity score. The substantia nigra from the rats was extracted for hematoxylin-eosin staining. Western blot analysis was performed to determine tyrosine hydroxylase and α-synuclein expression. RESULTS： Hematoxylin-eosin staining revealed a significant reduction in the number of substantia nigral neurons in the rotenone group, in addition to neurodegradation, hypopigmentation, and pyknosis. In the rifampicin pre-treatment and post-treatment groups, the number of dopaminergic neurons was significantly increased compared with the rotenone group （P 〈 0.01）, with slight neuronal damage. Compared with the rotenone group, substantia nigral tyrosine hydroxylase expression was significantly increased in the rifampicin pre-treatment and post-treatment groups （P 〈 0.01）, but α-synuclein expression and modified neurological severity scores were significantly decreased （P 〈 0.01）. In addition, the effect of rifampicin in the pre-treatment group was superior to the post-treatment group. There was no significant difference in tyrosine hydroxylase and α-synuclein expression, or in the modified neurological severity scores, between the blank control and rifampicin groups （P 〉 0.05）. CONCLUSION： Rifampicin significantly attenuated neuropathological and behavioral motor deficits induced by rotenone. Moreover, rifampicin enhanced tyrosine hydroxylase expression, but inhibited α-synuclein expression. The effect of rifampicin pre-treatment was superior to rifampicin post-treatment.

Argon preconditioning protects neuronal cells with a Toll-like receptor-mediated effect

The noble gas argon has the potential to protect neuronal cells from cell death.So far,this effect has been studied in treatment after acute damage.Preconditioning using argon has not yet been investigated.In this study,human neuroblastoma SH-SY5Y cells were treated with different concentrations of argon(25%,50%,and 74%;21%O_(2),5%CO_(2),balance nitrogen)at different time intervals before inflicting damage with rotenone(20μM,4 hours).Apoptosis was determined by flow cytometry after annexin V and propidium iodide staining.Surface expressions of Toll-like receptors 2 and 4 were also examined.Cells were also processed for analysis by western blot and qPCR to determine the expression of apoptotic and inflammatory proteins,such as extracellular-signal regulated kinase(ERK1/2),nuclear transcription factor-κB(NF-κB),protein kinase B(Akt),caspase-3,Bax,Bcl-2,interleukin-8,and heat shock proteins.Immunohistochemical staining was performed for TLR2 and 4 and interleukin-8.Cells were also pretreated with OxPAPC,an antagonist of TLR2 and 4 to elucidate the molecular mechanism.Results showed that argon preconditioning before rotenone application caused a dose-dependent but not a time-dependent reduction in the number of apoptotic cells.Preconditioning with 74%argon for 2 hours was used for further experiments showing the most promising results.Argon decreased the surface expression of TLR2 and 4,whereas OxPAPC treatment partially abolished the protective effect of argon.Argon increased phosphorylation of ERK1/2 but decreased NF-κB and Akt.Preconditioning inhibited mitochondrial apoptosis and the heat shock response.Argon also suppressed the expression of the pro-inflammatory cytokine interleukin-8.Immunohistochemistry confirmed the alteration of TLRs and interleukin-8.OxPAPC reversed the argon effect on ERK1/2,Bax,Bcl-2,caspase-3,and interleukin-8 expression,but not on NF-κB and the heat shock proteins.Taken together,argon preconditioning protects against apoptosis of neuronal cells and mediates its action via Toll-like receptors.Argon may represent a promising therapeutic alternative in various clinical settings,such as the treatment of stroke.

Electroacupuncture-regulated neurotrophic factor mRNA expression in the substantia nigra of Parkinson's disease rats

Acupuncture for the treatment of Parkinson＇s disease has a precise clinical outcome. This study investigated the effect of electroacupuncture at Fengfu （GV16） and Taichong （LR3） acupoints in rat models of Parkinson＇s disease induced by subcutaneous injection of rotenone into rat neck and back. Reverse transcription-PCR demonstrated that brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor mRNA expression was significantly increased in the substantia nigra of rat models of Parkinson＇s disease, and that abnormal behavior of rats was significantly improved following electroacupuncture treatment. These results indicated that electroacupuncture treatment upregulated brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor mRNA expression in the substantia nigra of rat models of Parkinson＇s disease. Thus, electroacupuncture may be useful in the treatment of Parkinson＇s disease.

DL-3-n-butylphthalide alleviates motor disturbance by suppressing ferroptosis in a rat model of Parkinson’s disease

DL-3-n-butylphthalide(NBP)-a compound isolated from Apium graveolens seeds-is protective against brain ischemia via various mechanisms in humans and has been approved for treatment of acute ischemic stroke.NBP has shown recent potential as a treatment for Parkinson’s disease.However,the underlying mechanism of action of NBP remains poorly understood.In this study,we established a rat model of Parkinson’s disease by intraperitoneal injection of rotenone for 28 successive days,followed by intragastric injection of NBP for 14-28 days.We found that NBP greatly alleviated rotenone-induced motor disturbance in the rat model of Parkinson’s disease,inhibited loss of dopaminergic neurons and aggregation ofα-synuclein,and reduced iron deposition in the substantia nigra and iron content in serum.These changes were achieved by alterations in the expression of the iron metabolism-related proteins transferrin receptor,ferritin light chain,and transferrin 1.NBP also inhibited oxidative stress in the substantia nigra and protected mitochondria in the rat model of Parkinson’s disease.Our findings suggest that NBP alleviates motor disturbance by inhibition of iron deposition,oxidative stress,and ferroptosis in the substantia nigra.

Neuroprotective effects of genistein on SH-SY5Y cells overexpressing A53T mutant α-synuclein

Genistein, a potent antioxidant compound, protects dopaminergic neurons in a mouse model of Parkinson＇s disease. However, the mecha- nism underlying this action remains unknown. This study investigated human SH-SYSY cells overexpressing the A53T mutant of α-synuclein. Four groups of cells were assayed： a control group （without any treatment）, a genistein group （incubated with 20 μM genistein）, a rote- none group （treated with 50 μM rotenone）, and a rotenone ＋ genistein group （incubated with 20 μM genistein and then treated with 50μM rotenone）. A lactate dehydrogenase release test confirmed the protective effect of genistein, and genistein remarkably reversed mitochondrial oxidative injury caused by rotenone. Western blot assays showed that BCL-2 and Beclin ! levels were markedly higher in the genistein group than in the rotenone group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling revealed that genistein inhibited rotenone-induced apoptosis in SH-SYSY cells. Compared with the control group, the expression of NFE2L2 and HMOX1 was significantly increased in the genistein ＋ rotenone group. However, after treatment with estrogen receptor and NFE2L2 channel blockers （ICI-182780 and ML385, respectively）, genistein could not elevate NFE2L2 and HMOX1 expression. ICI-182780 effectively prevented genistein-mediated phosphorylation of NFE2L2 and remarkably suppressed phosphorylation of AKT, a protein downstream of the estrogen receptor. These findings confirm that genistein has neuroprotective effects in a cell model of Parkinson＇s dis- ease. Genistein can reduce oxidative stress damage and cell apoptosis by activating estrogen receptors and NFE2L2 channels.

Bougainvillea spectabilis flowers extract protects against the rotenone-induced toxicity

Objective:To investigate the effect of two extracts of Bougainvillea spectabilis(B. spectabilis) flowers with yellow and pink/purple on brain oxidative stress and neuronal damage caused in rats by systemic rotenone injection. Methods:Rotenone 1.5 mg/kg was given three times per week alone or in combination with B. spectabilis flowers extracts(25 mg or 50 mg) via the subcutaneous route for 2 weeks. Brain concentrations of the lipid peroxidation marker malondialdehyde(MDA),reduced glutathione,nitric oxide(nitrite),the pro-inflammatory cytokine interleukin-1beta(Il-1β) as well as butyrylcholinesterase,and paraoxonase-1(PON-1) activities,were determined. Histopathology and caspase-3 immunohistochemistry were also performed. Results:Rotenone resulted in significant increases of brain MDA(the product of lipid peroxidation),and nitric oxide content along with decreased brain reduced glutathione. There were also marked and significant inhibition of brain PON-1 and BCh E activities and increased Il-1β in brain of rotenone-treated rats. B. spectabilis flowers extract itself resulted in brain oxidative stress increasing both lipid peroxidation and nitrite content whilst inhibiting PON-1 activity. The yellow flowers extract inhibited BCh E activity and increased brain Il-1β. When given to rotenone-treated rats,B. spectabilis extracts,however,decreased lipid peroxidation while their low administered doses increased brain GSH. Brain nitrite decreased by the pink extract but showed further increase by the yellow extract. Either extract,however,caused further inhibition of PON-1 activity while the yellow extract resulted in further inhibition of BChE activity. Histopathological studies indicated that both extracts protected against brain,liver and kidney damage caused by the toxicant. Conclusions:These data indicate that B. spectabilis flowers extracts exert protective effect against the toxic effects of rotenone on brain,liver and kidney. B. spectabilis flowers extracts decreased brain lipid peroxidation and prevented neuronal death due to rotenone and might thus prove the value in treatment of Parkinson's disease.