Glutamate-mediated oxidative stress causes neuronal cell death by increasing intracellular Ca2+ uptake, reactive oxidative species (ROS) generation, mitogen-activated protein kinase (MAPK) activation, and translocation of apoptosis-inducing factor (AIF) to the nucleus. In the current study, we demonstrated that corydaline exerts potent neuroprotective effects against glutamate-induced neurotoxicity. Treatment with 5 mmol/L glutamate increased cellular Ca2+ influx, ROS generation, MAPK activation, and AIF translocation. In contrast, corydaline treatment decreased cellular Ca2+ influx and ROS generation. Western blot analysis revealed that glutamate-mediated MAPK activation was attenuated by corydaline treatment. We further demonstrated that corydaline treatment inhibited the glutamate-mediated translocation of AIF to the nucleus. We propose that corydaline is a promising lead structure for the development of safe and effective neuroprotectants.

To investigate the in vivo cognitive effects of syringic acid(SA), Y-maze and passive avoidance tests were performed in amyloid-β(Aβ)-induced cytotoxicity. Learning and memory impairment by Aβ neurotoxicity was partially recovered in Institute of Cancer Research(ICR) mice orally administered SA(10mg/kg of body weight). The SA treated group showed an inhibitory effect on acetylcholinesterase(AChE) that was extracted from mice brain tissue after in vivo tests. Aβ-induced oxidative stress was also examined by malondialdehyde(MDA) and 2',7,-dichlorofluorescein diacetate(DCF-DA) assays, and lipid peroxidation of brain homogenates and cellular oxidative stress were reduced by SA. In cell viability assays using 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide(MTT), lactate dehydrogenase(LDH) leakage, and caspase 3/7 activity, the SA treated group showed relatively effective protection against Aβ-induced neurotoxicity compared to the others. Consequently, these results suggest that SA in black soybean seed coat extract might improve cognitive function because of its neuronal cell protective effects against oxidative stress and the inhibitory effect of AChE as a cholinergic enzyme.

In order to examine toxic effect of Jangwonhwan on cultured mouse cerebral cortical neurons inhibited by neurotoxicity induced by Xanthine Oxidase/Hypoxanthine(XO/HX), MTT and lipid peroxidation assay were performed after cerebral cortical neurons were preincubated with various concentrations of Jangwonhwan water extract before treatment of cells with XO/HX. The result were as follows ; 1. XO/HX induced cell degeneration such as the decrease of cell viability was measured by MTT in the cultured mouse cerebral cortical neurons 2. Jangwonhwan water extract was effective in the decrease of lipid peroxidation of neurons produced by XO/HX. From the above results, it is suggested that Xanthine Oxidase/Hypoxanthine(XO/HX) induces the inhibition of cell viability in cultuerd mouse cerebral cortical neurons and Jangwonhwan was effective in cultured neurons damaged by XO/HX.

Background : It is well known that Alzheimer`s disease (AD) is associated with neuronal loss and accumulation of extracellular senile plaque, whose major constituent is β-amyloid peptide (Aβ). In cell cultures, Aβ can directly stimulate neuronal cell death and make neurons susceptible to excitotoxicity which may include glutamate release and N-methyl-D-aspartate (NMDA) receptor activation. There are numerous reports in the literature of Cedrela sinensis (CS) for pro-apoptotic effects. It was hypothesized that CS might protect neurons against neurodegeneration in AD due to its pro-apoptotic effects. The current study aimed to determine the protective effect of ethanol extract from the leave of CS on Aβ (25-35)-induced neuronal cell death in primary cultured rat cortical neurons. Methods and Results : Cerebral neurons were collected from embryonic day 15 SD rat fetuses and were cultured on DMEM with serum. Neurotoxicity experiments were proceeded on cultured neurons after 4-5 days in vitro. Cultured neurons were treated with 10 μM Aβ (25-35) for 24 h or 1 mM NMDA for 20 h to induce neuronal death. CS was applied 20 min before the treatment with Aβ (25-35) or NMDA and also present in the medium during the incubations. Colorimetric MTT assay and Hoechst 33342 staining were used to estimate viability of neurons. Western blot analysis was carried out to examine the expression levels of anti-apoptotic and pro-apoptotic proteins. CS (5 and 10 ㎍/㎖) significantly inhibited Aβ (25-35)-induced apoptotic neuronal cell death in cultured cortical neurons. CS also inhibited Aβ (25-35)-induced change of apoptosis-related protein expression in western blot analysis. Furthermore CS (5 and 10 ㎍/㎖) reuduced NMDA-induced neuronal cell death. This study demonstrated that NMDA glutamate receptor activation is related with Aβ (25-35)-induced neuronal apoptotic death. Conclusion : CS protected culterd neurons against Aβ (25-35)-induced neurotoxicity probably via inhibition of NMDA receptor activation. These results suggest that CS can prevent the progression of neurodegenerative disease such as Alzheimer's disease.

Background : Alzheimer`s disease (AD) is characterized by neuronal loss and extracellular senile plaque, whose major constituent is β-amyloid (Aβ), a 39-43 amino acid peptide derived from amyloid precursor protein. In cultures, Aβ can directly induce neuronal cell death and can render neurons vulnerable to excitotoxicity which may involve glutamate release and N-methyl-D-aspartate (NMDA) receptor. Silybum marianum (SM) has been used for centuries to treat liver disease due to its antioxidant, and anti-inflammatory properties. In particular, Silymarin, an active constituent of SM, has been reported to decrease lipid peroxidation. Therefore we hypothesized that SM might protect neurons against neurodegeneration in AD due to its antioxidant and anti-inflammatory activities. In the present study, the protective effect of ethanol extract from the stem of SM on Aβ (25-35)-induced neuronal cell death was examined in primary cultured rat cortical neurons. Methods and Results : Primary cultured cortical neurons were prepared using embryonic day 15 SD rat fetuses. Neurotoxicity experiments were performed on cultured neurons after 4-5 days in vitro. The cells were treated with 10 μM Aβ (25-35) or 1 mM NMDA for 36 h or 14 h, respectively. SM was applied 15 min before treatment of Aβ (25-35) or NMDA and also present in the medium during the incubations. The viability of neurons was monitored using a colorimetric MTT assay and Hoechst 33342 staining. The expression levels of anti-apoptotic and pro-apoptotic proteins were detected by western blot. An Ethanol extract of the stem of SM (10 and 50 μg/ml) significantly prevented Aβ (25-35)-induced apoptotic neuronal cell death in cultured cortical neurons. Furthermore SM inhibited Aβ (25-35)-induced decrease of anti-apoptotic protein, Bcl-2, and increase of pro-apoptotic proteins, Bax and active caspase-2, in western blot analysis. SM (10 and 50 μg/ml) also reduced NMDA-induced neuronal cell death. These results suggest that NMDA glutamate receptor activation is implicated in Aβ (25-35) -induced neuronal apoptotic death. Conclusion : The present study suggests that SM has a possible therapeutic role for preventing the progression of neurodegenerative disease such as Alzheimer's disease.

Background : Ischemic stroke is a common cause of adult disability and death worldwide. Excessive oxidative stress is an important pathogenic mechanism in ischemic stroke. Major reduction of endogenous antioxidative systems increases production of free radicals inducing peroxidation of lipid, protein, and nucleic acid. 1,3-Dipalmitoyl-2-oleoylglycerol (DPOG) is a triglyceride found in oils from various natural sources such as palm kernels, sunflower seeds and rice bran. We found DPOG as an active constituent of rice bran oil. In the present study, we investigated neuroprotective effect of DPOG derived from rice bran oil on excitotoxicity in cultured neurons and on ischemic brain injury in rats. Methods and Results : Transient focal ischemic brain damage was induced by 2 h middle cerebral artery occlusion followed by 24h reperfusion (MCAO/reperfusion) in rats. After MCAO/reperfusion, the infarct and edema volume of brain tissue was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining methods. Glutathione concentration and lipid peroxidation rate were measured in brain tissue. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), inflammatory factors, and anti-apoptotic and pro-apoptotic proteins in brain tissue were detected by Western blot. Cerebral cortical neuronal cells were cultured in 15-days-old fetus. Cortical neurons were incubated with 1 mM N-methyl-D-aspartate (NMDA) for 14 h to produce excitotoxicity. Cell viability was measured by MTT assay. DPOG (1-5 mg/kg) significantly reduced MCAO/reperfusion-induced infarction and edema formation, neurological deficits, and brain cell death. Depletion of glutathione level and lipid peroxidation induced by MCAO/reperfusion were inhibited by administration of DPOG. The increase of phosphorylated MAPKs, inflammatory factors, and proapoptotic proteins and the decrease of antiapoptotic protein in ischemic brain were significantly inhibited by treatment with DPOG. DPOG (0.1-10 uM) inhibited 1 mM NMDA-induced neuronal cell death in cultured cortical neurons. Conclusion : From the above results, the present study provides an evidence that DPOG derived from rice bran oil might be effectively applied for the treatment of ischemic stroke.

Background : Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive memory loss, cognitive impairment and personality defects accompanied by diffuse structural abnormalities in the brain. The major pathological hallmarks of AD include beta amyloid (Aß) protein deposition, presence of neurofibrillary tangles and neurodegeneration of cholinergic neurons. Aß, a 39-43 amino acid proteolytic fragment of amyloid precursor protein, is the major constituent of the senile plaques. Rice bran, the major byproduct of the rice milling industry, is the source of a high quality vegetable oil. Rice bran oil (RBO) has attracted much medicinal attention for its strong hypocholesterolemic properties because of its balanced fatty acid composition and high levels of antioxidant phytochemicals such as oryzanols, tocopherols and tocotrienols. The present study aims to investigate the protective effect of RBO against Aß (25-35)-induced neurotoxicity in in vitro and in vivo. Methods and Results : Memory impairment was produced by intracerebroventricular (i.c.v) microinjection of 15 nmol Aß (25-35) and measured by passive avoidance test in ICR mice. Glutathione concentration, lipid peroxidation rate and acetylcholine esterase activity were measured in mice brain. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), inflammatory factors, and anti-apoptotic and pro-apoptotic proteins in mice brains were detected by Western blot. Cerebral cortical neuronal cells were cultured from 15-days-old fetus. Cortical neurons were incubated with 10 μM Aß (25-35) for 36 h. Cell viability was measured by MTT assay. Chronic treatments of RBO (0.1-1 ml/kg, 8 days, p.o.) protected against memory impairment induced by Aß (25-35). Depletion of glutathione level, lipid peroxidation and increased acetylcholine esterase activity by the treatment with Aß (25-35) were inhibited by administration of RBO. The increase of phosphorylated MAPKs, inflammatory factors, and proapoptotic proteins and the decrease of antiapoptotic protein in Aß (25-35)-administered mice brain were significantly inhibited by treatment with RBO. RBO (0.1-5ul/ml) inhibited 10μM Aß (25-35)-induced neuronal cell death in cultured cortical neurons. Conclusion : The present study suggests the role of RBO as a promising therapeutic for neurodegenerative diseases like AD and stroke.

Background : Rice bran is the outer brown layer of the rice grain and produced when rice is milled. The basic components of rice bran are fiber, lipids, amino acids, vitamins, and minerals. The oil extracted from this bran is called rice bran oil. Although whole rice bran in itself does not have anti-cholesterol properties, its oil offers significant benefits. Ischemic stroke is a major cause of morbidity and mortality worldwide. The cessation or critical reduction of blood flow in brain during acute stroke results in deprivation of the oxygen and glucose supplies, which can produce a local brain ischemia and injury. It is well established that excitotoxicity, a type of neurotoxicity evoked by elevated extracellular glutamate level, is a primary contributor to ischemic neuronal death. The present study aims to investigate the neuroprotective effect of Rice bran oil (RBO) on ischemic brain injury in rats and on excitotoxicity in cultured neurons. Methods and Results : Transient focal ischemic brain damage was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/reperfusion) in rats. After MCAO/reperfusion, the infarct and edema volumes of brain tissues were measured using 2,3,5-triphenyltetrazolium chloride (TTC) staining methods. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), inflammatory factors, and anti-apoptotic and pro-apoptotic proteins in brain tissue were detected by Western blot. Primary cortical neuronal cultures were prepared using SD rat fetuses on embryonic days 15. Cortical neurons were treated with N-methyl-D-aspartate (NMDA) (1 mM) for 14 h to produce neuronal cell death. Cell viability was measured by MTT assay. RBO inhibited the formation of infartion and edema in MCAO/reperfusion–induced ischemic brains. The increase of phosphorylated MAPKs, inflammatory factors, and proapoptotic proteins and the decrease of antiapoptotic protein in ischemic brains were significantly inhibited by treatment with RBO. RBO (0.01-1ul/ml) inhibited 1 mM NMDA-induced neuronal cell death in cultured cortical neurons. Conclusion : These results suggest that RBO might be a promising therapeutic for neurodegenerative disease such as stroke.

The present study investigated an ethanol extract (SSB) of a mixture of three medicinal plants of Vitisamurensis, Aralia cordata, and Glycyrrhizae radix for possible neuroprotective effects on neurotoxicity induced byAmyloid β protein (Aβ) (25-35) in cultured rat cortical neurons and antidementia activity in mice. Exposure of cultured cor-tical neurons to 15μM Aβ (25-35) for 36h induced neuronal apoptotic death. At 1-30㎍/㎖, SSB inhibited neuronal death,elevation of intracellular calcium concentration ([Ca²+]i), and generation of reactive oxygen species (ROS) induced by Aβ(25-35) in cultured cortical neurons. Memory impairment and increase of acetylcholinesterase activity induced by intra-cerebroventricular injection of mice with 16nmol Aβ (25-35) was inhibited by chronic treatment with SSB (25, 50 and100㎎/㎏, p.o., for 8 days). From these results, it is suggested that antidementia effect of SSB is due to its neuroprotectiveeffect against Aβ (25-35)-induced neurotoxicity and that SSB may have a therapeutic role in preventing the progression ofAlzheimer’s disease.

The present study investigated an ethanol extract of Chaenomeles sinensis fruit (CSF) for possible neuroprotective effects on neurotoxicity induced by amyloid β protein (Aβ) (25-35) in cultured rat cortical neurons and also for antidementia activity in mice. Exposure of cultured cortical neurons to 10μM Aβ (25-35) for 36 h induced neuronal apoptotic death. At 0.1-10μg/ml, CSF inhibited neuronal death, elevation of intracellular calcium concentration ([Ca2+]i), and generation of reactive oxygen species (ROS) induced by Aβ (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of mice with 15 nmol Aβ (25-35) was inhibited by chronic treatment with CSF (10, 25 and 50 mg/kg, p.o. for 7 days) as measured by a passive avoidance test. CSF (50 mg/kg) inhibited the increase of cholinesterase activity in Aβ (25-35)-injected mice brain. From these results, we suggest that the antidementia effect of CSF is due to its neuroprotective effect against Aβ (25-35)-induced neurotoxicity and that CSF may have a therapeutic role for preventing the progression of Alzheimer's disease.

The present study investigated an ethanol extract (HS0608) of a mixture of three medicinal plants of Curcumalongae radix, Phellinus linteus, and Scutellariae radix for possible neuroprotective effects on neurotoxicity induced by amyloid βprotein (Aβ) (25-35) in cultured rat cortical neurons and antidementia activity in mice. Exposure of cultured cortical neurons to10µM Aβ (25-35) for 36h induced neuronal apoptotic death. At 1-50㎍/㎖, HS0608 inhibited neuronal death, elevation of intra-cellular calcium concentration ([Ca2+]i), and generation of reactive oxygen species (ROS) induced by Aβ (25-35) in primary cul-tures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of ICR mice with 15 nmol Aβ (25-35) wasinhibited by chronic treatment with HS0608 (25, 50 and 100㎎/㎏, p.o. for 7 days) as measured by a passive avoidance test. Fromthese results, we suggest that the antidementia effect of HS0608 is due to its neuroprotective effect against Aβ (25-35)-inducedneurotoxicity and that HS0608 may have a therapeutic role in preventing the progression of Alzheimer’s disease.

Moutan cortex, the root bark of Paeonia suffruticosa Andrews (Paeoniaceae), has pharmacological effects such as anti-inflammatory, antiallergic, analgesic and antioxidant activities. We investigated a methanol extract of Moutan cortex for neuroprotective effects on neurotoxicity induced by amyloid β protein (Aβ) (25-35) in cultured rat cortical neurons. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 24 h induced neuronal apoptotic death. Moutan cortex inhibited 10 μM Aβ (25-35)-induced neuronal cell death at 30 and 50 μg/ml, which was measured by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. Moutan cortex inhibited 10 μM Aβ (25-35)-induced elevation of intracellular calcium concentration ([Ca2+]i), and generation of reactive oxygen species (ROS) which were measured by fluorescent dyes. Moutan cortex also inhibited glutamate release into medium induced by 10 μM Aβ (25-35), which was measured by HPLC. These results suggest that Moutan cortex prevents Aβ (25-35)-induced neuronal cell damage by interfering with the increase of [Ca2+]i, and then inhibiting glutamate release and ROS generation. Moutan cortex may have a therapeutic role in preventing the progression of Alzheimer's disease.

Amyloid peptide()은 지방산화 및 free radical의 생산에 의해 신경세포의 apoptosis를 유도하거나 산화적 스트레스를 증가시키는 원인이 되는 물질로 알려져 있으며, 알츠하이머와 같은 신경계 질환은 뇌에 아밀로이드베타 단백질들의 축적에 의해서 일어난다. 따라서 본 연구에서는 수분 활성도 0.813인 분말 녹차를 저장기간별로 저장한 후 에서 5분간 추출한 분말 녹차 열수추출물을 이용하여 아밀로이드 베타단백질에 의해 유도된

The preventive effects of sodium molybdate on the acute toxicity of lead were studied by investigating tissue accumulation of lead, changes of nerve conduction velocity and concentrations of metabolites related to function of sciatic nerve in rats treated with lead, sodium molybdate and both, respectively. In lead-intoxicated rat, the conduction velocity, myo-inositol concentration and Na+/K+ ATPase activity of sciatic nerve were decreased by about 33 %, 48 % and 58 %, respectively. However, sodium molybdate treatment significantly normalized the conduction velocity, Na+/K+ ATPase activity and myo-inositol concentration of sciatic nerve in lead-intoxicated rat. Also, sodium molybdate treatment decreased the contents of lead in blood and sciatic nerve through promotion of urinary excretion of lead. But sodium molybdate treatment did not affect the glucose concentration in sciatic nerve. These results suggest that sodium molybdate prevented peripheral neuropathy not only by reducing lead contents in sciatic nerve and blood, but also by enhancing Na+/K+ ATPase activity in sciatic nerve.