Search

Formononetin (FMNT) is an isoflavone found in many herbs including Trifolium pratense L., Spatholobus suberectus Dunn., and Astragalus mongholicus Bunge. The purpose of this study is to investigate pharmacological properties of FMNT on neurotoxicity induced by N-methyl-D-asparate (NMDA) in primary-cultured cortical neurons. The cell viability was significantly decreased after exposure to NMDA (200 μM) for 40 min. Pretreatment of FMNT (10 μM) for 12 h significantly attenuated the cell loss induced by NMDA exposure. Flow cytometry analysis revealed that treatment of FMNT attenuated the number of apoptotic cells, especially the early phase apoptotic cells, induced by NMDA exposure. Western blot analysis showed that FMNT regulated the expression of apoptosis-related proteins by increasing the levels of Bcl-2 and pro-caspase-3 and decreasing the levels of Bax and caspase-3. These findings demonstrate that FMNT is capable of protecting neurons from NMDA-evoked excitotoxic injury and has a potential perspective to the clinical treatment for neurodegenerative disorders in central nervous system., (Copyright © 2013 John Wiley & Sons, Ltd.)

Hyperoside (Hyp) is a flavonoid compound isolated from a folk remedy, Rhododendron ponticum L. leaves. It has been shown to have neuroprotective effects both in vivo and in vitro. However, little is known about the effects of Hyp on the neuronal apoptosis induced by glutamate. The present study showed that Hyp significantly attenuated, in a concentration-dependent manner, the apoptosis induced by the exposure of cultured neurons to NMDA. Western blot analysis revealed that Hyp antagonized the expression of excess NR2B-containing NMDA receptors; however, it had no effect on the expression of NR2A-containing NMDA receptors. Our results demonstrate that the neuroprotective effect of Hyp owes, at least partially, to its differential modulation of NR2A- and NR2B-containing NMDA receptors.

1. Serotonin (5-hydroxytryptamine; 5-HT) plays important roles in the development of cardiac hypertrophy via activation of 5-HT receptors. The aim of the present study was to investigate the role of 5-HT(2B) receptors in the development of cardiomyocyte apoptosis and hypertrophy associated with noradrenaline (NA) overload. 2. Cardiac hypertrophy was induced in rats by intraperitoneal injection of 1.5 mg/kg NA for 4 weeks. Starting from Day 15, 5-HT2B receptor antagonist SB 204741 (i.p., 0.5 or 2 mg/kg) or SDZ SER 082 (i.p., 1 mg/kg) was injected twice daily for another 14 days. Whole-cell patch-clamp techniques were used to record ionic currents in freshly isolated ventricular cardiomyocytes. Western blot and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) assays were used to assess myocardial apoptosis. 3. Expression of 5-HT(2B) receptors was enhanced in the hypertrophic left ventricle induced by NE overload in vivo. The 5-HT(2B) receptor antagonist SB 204741 partially reversed cardiac hypertrophy induced by NE overload (P < 0.05) and decreased L-type calcium currents in ventricular cardiomyocytes (P < 0.05). In addition, SB 204741 notably attenuated myocardial apoptosis, as evidenced by downregulation of Bax and caspase 3 (P < 0.05) and upregulation of the anti-apoptotic Bcl-2 protein (P < 0.05). 4. In conclusion, the data suggest an involvement of 5-HT(2B) receptors in the generation of apoptotic events associated with cardiac remodelling during increased adrenergic stimulation.

Objective: To investigate the effects of serum from crush injury rats on vascular endothelial cell apoptosis and their potential mechanism., Methods: Bovine aorta endothelial cells were cultured in vitro and the effects of serum from crush injury rats on cell apoptosis and intracellular calcium concentration ([Ca2+]i) were observed. Meanwhile, the levels of rat blood plasma endothelin-1 (ET-1) and atrial natriuretic peptide(ANP) were measured., Results: Compared with normal rat serum treatment, the cell apoptosis rate decreased from (8.26+/-1.75)% to (2.75+/-0.90)%, while the concentration of [Ca2+]i increased from (96.98+/-3.95) to (118.79+/-3.22) nmol/L in serum from crush injury rats, respectively. The concentration of ET-1 and ANP increased significantly in crush injury rat serum., Conclusion: Serum from crush injury rats could inhibit apoptosis of the vascular endothelial cells. These effects may be related to increased level of [Ca2+]i mediated by ET-1 and ANP.

Objective: To investigate whether heroin can directly induce apoptosis in primary cultured cortical neurons of rat's brain., Methods: Cultured primary neurons cultures were obtained from cerebral cortex of embryo rats. After 7 days, the cells were incubated with different concentrations of heroin (purity-80%) for 24 hours. The neuronal survival was assessed by cell viability counting with fluorescent diacetate (FDA) staining. The morphological and biochemical changes were observed with Hoechst 33258 fluorescent staining and then analyzed by agarose gel electrophoresis, respectively., Results: After treatment with different concentrations of heroin, the neurons showed a decreased survival rate in a dose dependent manner, and there was a significant difference in the survival rate between the heroin group and the control group (P < 0.05). When exposed to different concentrations of heroin, neurons exhibited the morphological and biochemical features of apoptosis, including cell shrinkage, neurite degeneration, network disappearance, condensation and aggregation of nuclear chromatin, and the formation of DNA ladders. With the increase of heroin concentration of rat's brain more apoptotic bodies were seen., Conclusion: Heroin can directly induce apoptosis in primary cultured cortical neurons in rat's brain.

Gastrodin is an active ingredient derived from the rhizome of Gastrodia elata. This compound is usually used to treat convulsive illness, dizziness, vertigo, and headache. This study aimed to investigate the effect of gastrodin on the autophagy of glial cells exposed to lipopolysaccharides (LPS, 1 µg/mL). Autophagy is a form of programmed cell death, although it also promotes cell survival. In cultured astrocytes, LPS exposure induced excessive autophagy and apoptosis, which were significantly prevented by the pretreatment cells with gastrodin (10 μM). The protective effects of gastrodin via autophagy inhibition were verified by the decreased levels of LC3-II, P62, and Beclin-1, which are classical markers for autophagy. Furthermore, gastrodin protected astrocytes from apoptosis through Bcl-2 and Bax signaling pathway. The treatment of astrocytes with rapamycin (500 nM), wortmannin (100 nM), and LY294002 (10 μM), which are inhibitors of mTOR and PI3K, respectively, eliminated the known effects of gastrodin on the inhibited Beclin-1 expression. Furthermore, gastrodin blocked the down-regulation of glutamine synthetase induced by LPS exposure in astrocytes. Our results suggest that gastrodin can be used as a preventive agent for the excessive autophagy induced by LPS. [ABSTRACT FROM AUTHOR]

Abstract: Oxymatrine (OMT) is a major bioactive component derived from Sophora flavescens Ait (kushen), which is widely used in Chinese medicine. Recent studies have shown that it has neuroprotective effects; however, its underlying mechanisms remain unclear. We focus on the mechanisms of pharmacologic action in OMT by detecting its pharmacological properties against focal cerebral ischemia in vivo and NMDA-induced neurotoxicity in vitro. OMT prevented cerebral ischemic injury in mice induced via a 2h middle cerebral artery occlusion and a 24h reperfusion, in vivo. In vitro cultured neurons challenged with N-methyl-d-aspartate (NMDA, 200μM) for 30min showed significant decrease in the viability of neurons; however, OMT was able to protect neurons against induced neurotoxicity via NMDA exposure. Western blot analysis revealed that OMT decreased the expression of Bax and repaired the balance of pro- and anti-apoptotic proteins. Furthermore, OMT significantly reversed the up-regulation of NR2B and inhibited the calcium overload in the cultured neurons after challenging the NMDA. OMT showed partial protection in the cortical neurons via down-regulation of NR2B containing NMDA receptors and up-regulation of Bcl-2 family. Our results provide new insights into the development of natural therapeutic anti-oxidants against ischemia. [Copyright &y& Elsevier]

Aims Flax Lignan ( FLL), a chemical widespread within the plant and animal kingdoms, has antioxidant, antiinfectious, and antitumor activities. However, little is known about the effects of FLL on the central nervous system ( CNS). Methods The neuroprotective actions of FLL against N-methyl-d-aspartate ( NMDA) are investigated in primary cultured cortical neurons by MTT assay. The expression levels of proteins related to apoptosis and GluN2-containing receptor were detected by Western blot analysis. Intracellular Ca2+ was measured under a confocal laser scanning microscope. Results After challenged with 100 μM NMDA for 30 min, loss of cell viability and excessive apoptotic cell death were observed in cultured cortical neurons. FLL protected the neurons against the NMDA-induced cell loss in a concentration-dependent manner. FLL also significantly inhibited the neuronal apoptosis induced by NMDA exposure through reversing intracellular concentration of Ca2+ overload and balancing of Bcl-2 and Bax expression. Furthermore, FLL significantly reversed the upregulation of GluN2B-containing NMDA receptors by exposure to NMDA, but did not affect the expression of GluN2A-containing NMDA receptor. Conclusions These findings suggest that FLL protects cortical neurons by inhibiting the expression of GluN2B-containing NMDA receptor and regulating the Bcl-2 family. [ABSTRACT FROM AUTHOR]

Summary 1. 17-β-oestradiol (E2) plays a critical role in neuroprotection through both genomic and non-genomic mechanisms. The aim of the present study was to investigate the role of G-protein-coupled receptor 30 (GPR30), a new kind of oestrogen receptor, in the neuroprotection against oxidative insult. 2. The neuroprotection evoked by GPR30 stimulation was examined in cultured cortical neurons. Hoechst 33258/propidium iodide double staining, flow cytometric analysis and western blotting were applied to assess neuronal apoptosis induced by H2O2. 3. We found that the GPR30 agonist, G1, and E2 attenuated apoptosis induced by H2O2 exposure. Furthermore, G1 (1 nmol/L) or E2 (1 nmol/L) significantly increased the levels of phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2), Bcl-2 and pro-caspase-3. Pretreatment with ICI182780, a highly selective nuclear oestrogen receptor antagonist that is used to block the classical ERα and ERβ receptors, did not totally block the neuroprotective effects of E2 (1 nmol/L) and had no effect on the neuroprotective effects of G1 (1 nmol/L). 4. Our data suggest that GPR30 is involved in the neuroprotection against oxidative insult. The neuroprotection evoked by GPR30 stimulation was associated with the signalling through the ERK1/2 kinase pathway. In addition, the anti-apoptotic activity of GPR30 was dependent on the expression of Bcl-2 and pro-caspase-3. GPR30 might be a potential therapeutic target for neuroprotection and oxidative stress. [ABSTRACT FROM AUTHOR]

1. Serotonin (5-hydroxytryptamine; 5-HT) plays important roles in the development of cardiac hypertrophy via activation of 5-HT receptors. The aim of the present study was to investigate the role of 5-HT2B receptors in the development of cardiomyocyte apoptosis and hypertrophy associated with noradrenaline (NA) overload. 2. Cardiac hypertrophy was induced in rats by intraperitoneal injection of 1.5 mg/kg NA for 4 weeks. Starting from Day 15, 5-HT2B receptor antagonist SB 204741 (i.p., 0.5 or 2 mg/kg) or SDZ SER 082 (i.p., 1 mg/kg) was injected twice daily for another 14 days. Whole-cell patch-clamp techniques were used to record ionic currents in freshly isolated ventricular cardiomyocytes. Western blot and terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling (TUNEL) assays were used to assess myocardial apoptosis. 3. Expression of 5-HT2B receptors was enhanced in the hypertrophic left ventricle induced by NE overload in vivo. The 5-HT2B receptor antagonist SB 204741 partially reversed cardiac hypertrophy induced by NE overload ( P < 0.05) and decreased L-type calcium currents in ventricular cardiomyocytes ( P < 0.05). In addition, SB 204741 notably attenuated myocardial apoptosis, as evidenced by downregulation of Bax and caspase 3 ( P < 0.05) and upregulation of the anti-apoptotic Bcl-2 protein ( P < 0.05). 4. In conclusion, the data suggest an involvement of 5-HT2B receptors in the generation of apoptotic events associated with cardiac remodelling during increased adrenergic stimulation. [ABSTRACT FROM AUTHOR]

Abstract: Glutamate is an important excitatory neurotransmitter in the central nervous system. Excessive accumulation of glutamate can cause excitotoxicity, which plays a key role in spinal cord injury, traumatic brain injury, stroke, and neurodegenerative diseases. Curculigoside (CCGS) is a major bioactive compound isolated from the rhizome of Curculigo orchioides Gaertn. CCGS has an extensive biological effect and has been used in Traditional Chinese Medicine. However, little is known about the neuroprotective effects of CCGS on glutamate-induced excitotoxicity. This study aims to evaluate the neuroprotective effects of CCGS in cultured cortical neurons. The results indicated that treatment with 1 and 10μM CCGS evidently prevented N-methyl-d-aspartate (NMDA)-induced neuronal cell loss and reduced the number of apoptotic and necrotic cells in a time- and concentration-dependent manner. The neuroprotective effects of CCGS are related to down regulating the apoptotic protein levels and reducing the production of intracellular reactive oxygen species in cultured cortical neurons. These findings give a new insight into the development of natural anti-excitotoxicity agents. [Copyright &y& Elsevier]