Protective effects of Lycium barbarum polysaccharide on neonatal rat primary cultured hippocampal neurons injured by oxygen-glucose deprivation and reperfusion
ABSTRACT This study investigated the protective effects of Lycium barbarum polysaccharide (LBP) on alleviating injury from oxygen-glucose deprivation/reperfusion (OGD/RP) in primary cultured rat hippocampal neurons. Cultured hippocampal neurons were exposed to oxygen-glucose deprivation (OGD) for 2 h followed by a 24 h re-oxygenation. The MTT assay and the lactate dehydrogenase (LDH) release were used to determine the neuron viability. Superoxide dismutase (SOD), Glutathione peroxidase (GSH-PX), malondialdehyde (MDA) were determined by spectrophotometry using commercial kits. Mitochondrial membrane potential (MMP) and the intracellular free calcium concentration ([Ca(2+)](i)) in hippocampal neurons were measured using the confocal laser scanning microscope (CLSM). Treatment with LBP (10-40 mg/l) significantly attenuated neuronal damage and inhibited LDH release in a dose-dependent manner. Furthermore, LBP enhanced activities of SOD and GSH-PX but it decreased their MDA content, inhibited [Ca(2+)](i) elevation and decrease of MMP in ischemia-reperfusion treated hippocampal neurons. These findings suggested that LBP may be a potential neuroprotective agent for cerebral ischemia-reperfusion injury.
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ABSTRACT: This study aims to investigate the neuroprotective effect of the rhizome of Gastrodia elata (GE) aqueous extract on beta-amyloid(A β )-induced toxicity in vivo and in vitro. Transgenic Drosophila mutants with A β -induced neurodegeneration in pan-neuron and ommatidia were used to determine the efficacy of GE. The antiapoptotic and antioxidative mechanisms of GE were also studied in A β -treated pheochromocytoma (PC12) cells. In vivo studies demonstrated that GE (5 mg/g Drosophila media)-treated Drosophila possessed a longer lifespan, better locomotor function, and less-degenerated ommatidia when compared with the A β -expressing control (all P < 0.05). In vitro studies illustrated that GE increased the cell viability of A β -treated PC12 cells in dose-dependent manner, probably through attenuation of A β -induced oxidative and apoptotic stress. GE also significantly upregulated the enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase, leading to the decrease of reactive oxidation species production and apoptotic marker caspase-3 activity. In conclusion, our current data presented the first evidence that the aqueous extract of GE was capable of reducing the A β -induced neurodegeneration in Drosophila, possibly through inhibition of apoptosis and reduction of oxidative stress. GE aqueous extract could be developed as a promising herbal agent for neuroprotection and novel adjuvant therapies for Alzheimer's disease.Evidence-based Complementary and Alternative Medicine 09/2013; 2013:516741. DOI:10.1155/2013/516741 · 2.18 Impact Factor
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ABSTRACT: In this study, we investigated the neuroprotective effect of oxysophoridine on ischemia and ischemia-like insults. Protection by oxysophoridine was studied at the in vivo level using a model of middle cerebral artery occlusion in mice and at the in vitro level using primary rat hippocampal neuronal cultures exposed to oxygen-glucose deprivation, a model of ischemia-like injury. The behavioral test was performed by using the neurological scores. The infarction volume of brain was assessed in the brain slices stained with 2,3,5-triphenyl tetrazolium chloride. The neuron apoptosis was evaluated by Hoechst 33342 staining. The morphological change in the neurons was examined using a Transmission Electron Microscope (TEM or EM). To evaluate neuron apoptosis, caspase-3, -9, and - 8 activities were measured using assay kits with an ELISA reader. The Western blotting assay was used to evaluate the release of cytochrome c and expression of caspase-3, Bcl-2, and Bax proteins. The quantitative real-time PCR assay was used to evaluate the release of cytochrome c and the expression of caspase-3 mRNA. Oxysophoridine-treated groups (62.5, 125, 250 mg/kg) markedly reduced neurological deficit scores and infarct volumes. Treatment with oxysophoridine (5, 20, 80 µmol/L) significantly attenuated neuronal damage, with evidence of decreased cell apoptosis and decreased cell morphologic impairment. Furthermore, treatment with oxysophoridine could effectively downregulate the expression of cytochrome c and caspase-3 in both mRNA and protein levels, and Bax in the protein level, and induce an increase of Bcl-2 in the protein level. The caspase-3, -9, and -8 activities were also inhibited. These findings suggested that oxysophoridine may be a potential neuroprotective agent for cerebral ischemia injury.Planta Medica 06/2013; 79(11). DOI:10.1055/s-0032-1328705 · 2.34 Impact Factor
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ABSTRACT: In the present study, oxygen-glucose deprivation followed by reperfusion (OGD/R), an in vitro model of ischemia, was used to evaluate the neuroprotective effect of isoquercetin in primary culture of rat cortical neuronal cells. It was found that isoquercetin administered prior to the insult could prevent OGD/R-induced intracellular calcium concentrations ([Ca(2+)]i) increase, lactate dehydrogenase (LDH) release and cell viability decrease. For the first time, isoquercetin is described as a neuroprotective agent that potentially explains the alleviation and prevention from OGD/R-induced injury in neurons. Mechanistic studies showed that the neuroprotective effect of isoquercetin was carried out by anti-inflammatory signaling pathway of inhibiting protein expression of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB), and mRNA expression of TNF-α and IL-6, accompanied by the anti-apoptotic signaling pathway of deactivation of extracellular-regulated kinase (ERK), Jun kinase (JNK) and p38, and inhibition of activity of caspase-3. Therefore, these studies highlighted the confirmation of isoquercetin, a flavonoid compound, as an anti-inflammation and anti-apoptosis factor which might be used as a therapeutic strategy for the ischemia/reperfusion (I/R) brain injury and related diseases.Neurochemistry International 10/2013; 63(8). DOI:10.1016/j.neuint.2013.09.018 · 2.65 Impact Factor