The young shoots of Aralia elata, Chaenomeles sinensis fruit and Glycyrrhizae radix are edible and traditionally used as anti-inflammatory and antioxidant agents. The present study was performed to investigate the protective effect of an ethanol extract mixture of these three medicinal plants (ACG) against amyloid β protein (Aβ) (25– 35)-induced memory impairment in an ICR mouse model. Memory impairment was induced by intracerebroventricular microinjection of 15 nmol Aβ (25–35) and assessed using the passive avoidance test and the Morris water maze test. The step-through latency in the passive avoidance test was decreased and the latency to reach the hidden platform in the Morris water maze test was increased in mice treated with Aβ (25–35), indicating memory impairment. This memory impairment induced by Aβ (25–35) was significantly prevented by chronic treatment with ACG (10, 25, and 50 mg/kg, p.o., 8 days). In memory impaired mice brain, cholinesterase activity and concentration of thiobarbituric acid reactive substance, a lipid peroxidation marker, were increased and glutathione level was decreased. These biochemical changes in Aβ (25–35)-treated mice were reversed by chronic administration of ACG. The present results suggest that antioxidant and anti-cholinesterase activities of ACG might be responsible for the inhibition of Aβ (25– 35)-induced memory impairment and that ACG preparation may have a therapeutic role in preventing the progression of Alzheimer’s disease.

Actinidia arguta (Actinidiaceae), which is commonly referred to as hardy kiwifruit, has been reported to possess anti-inflammatory, anti-allergic and antioxidative properties. The protective effect of the leaves and stems of A. arguta against amyloid β protein (Aβ) (25-35)-induced cultured neuronal cell death and memory impairment was investigated in the current study. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 24 h induced significant neuronal death as assessed by a 3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. However, A. arguta (10 and 50 μg/ ml) prevented Aβ (25-35)-induced apoptotic neuronal death in cultured cortical neurons. A. arguta also inhibited the 100 μM H2O2-induced decrease of the MTT reduction rate in cultured neurons. Memory impairment was produced by intracerebroventricular microinjection of 15 nmol Aβ (25- 35) and examined using the passive avoidance test in ICR mice. Chronic treatments with A. arguta (50 and 100 mg/ kg, 14 days, p.o.) significantly prevented memory impairment induced by Aβ (25-35), and A. arguta inhibited the Aβ (25-35)-induced increase of cholinesterase activity in the brains of memory impaired mice. These results suggest that A. arguta might be able to inhibit Aβ (25-35)-induced neuronal death and memory impairment via antioxidative and anti-cholinesterase effects and that A. arguta could have a therapeutic role for preventing the progression of neurodegeneration in Alzheimer’s disease.

Alzheimer’s disease (AD), a progressive neurodegenerative disorder that deprives the patient of memory, is associated mainly with extracellular senile plaque induced by the accumulation of amyloid β protein (Aβ). Silybum marianum (Asteraceae; SM) is a medicinal plant that has long been used in traditional medicine as a hepatoprotective remedy owing to its antioxidant and anti-inflammatory activities. The present study examined the methanol extract of the aerial parts of SM for neuroprotection against Aβ (25-35)-induced neuronal death in cultured rat cortical neurons to investigate a possible therapeutic role of SM in AD. The primary cortical neuron cultures were prepared using embryonic day 15 to 16 SD rat fetuses. Cultured cortical neurons exposed to 10 μM Aβ (25-35) for 36 h underwent neuronal cell death. At 10 and 50 μg/mL, SM prevented Aβ (25-35)-induced neuronal cell death and apoptosis in cultured cortical neurons. Furthermore, SM inhibited the Aβ (25-35)-induced decrease in anti-apoptotic protein, Bcl-2, and the increase in the proapoptotic proteins, Bax and active caspase-3. Cultured cortical neurons exposed to 1 mM N-methyl-D-aspartate (NMDA) for 14 h induced neuronal cell death. SM (10 and 50 μg/mL) prevented NMDA-induced neuronal cell death. These results suggest that SM inhibited Aβ (25-35)-induced neuronal apoptotic death via inhibition of NMDA receptor activation and that SM has a possible therapeutic role in preventing the progression of neurodegeneration in AD.

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 directly induce neuronal cell death and can include excessive generation of free radicals and peroxidative injury to proteins, lipids, and other macromolecules. Actinidia arguta, generally called hardy kiwifruit, has been reported to possess anti-inflammatory, anti-allergic and antioxidative properties. The present study aims to investigate the neuroprotective effect of the leaves and stems of A. arguta using in vitro cultured neurons and in vivo experimental animals. Methods and Results : Primary cortical neuronal cultures were prepared using Sprague-Dawley (SD) rat fetuses on embryonic days 15. Neurotoxicity experiments were performed on neurons after 3-4 days in culture. Cultured neurons were treated with 10 μM Aβ (25-35) for 24 h to produce neurotoxicity. In addition, cultured neurons were treated with H2O2 (100 μM) for 15 min and then incubated for 12 h in H2O2-free medium. Viability of cultured neurons was measured by a colorimetric MTT assay. Hoechst 33342 staining of neurons was carried out to examine Aβ (25-35)-induced apoptotic neuronal death. A. arguta over the concentration of 10 to 50 ㎍/㎖ prevented Aβ (25-35) (10 μM)-induced apoptotic neuronal death, and inhibited H2O2-induced decrease of MTT reduction rate. These results suggest that oxidative stress is implicated in Aβ (25-35)-induced neuronal apoptotic death. Memory impairment was produced by intracerebroventricular (i.c.v) microinjection of 15 nmol Aß (25-35) and examined using passive avoidance test in ICR mice. Chronic treatments with A. arguta (14 days, p.o.) protected memory impairment induced by Aß (25-35). Conclusion : The present study suggests that A. arguta has a therapeutic role for preventing the progression of neurodegenerative disease such as AD.

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 : 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.

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.

Sanguisorbae radix (SR) from Sanguisorba officinalis L. (Losaceae) is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of SR on amyloid β Protein(25-35) (Aβ (25-35)), a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. SR, over a concentration range of 10-50 μg/ml, inhibited the Aβ (25-35) (10 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. Pretreatment of SR (50 μg/ml) inhibited 10 μM Aβ (25-35)-induced elevation of cytosolic calcium concentration ([Ca2+]c), which was measured by a fluorescent dye, fluo-4 AM. SR (10 and 50 μg/ml) inhibited glutamate release into medium induced by 10 μM Aβ(25-35), which was measured by HPLC, and generation of reactive oxygen species. These results suggest that SR prevents Aβ (25-35)-induced neuronal cell damage in vitro.

Caulis Bambusae in Taenia is widely used in Korea and China due to its various pharmacological activity. The present study aims to investigate the effect of the methanol extract of Caulis Bambusae in Taenia (CB) from Phyllostachys nigra Munro var. henonis Stapf (Gramineae) on amyloid β protein (25-35) (Aβ (25-35)), a synthetic 25-35 amyloid peptide, -induced neurotoxicity using cultured rat cortical neurons. CB, over a concentration range of 10-50μg/μl, inhibited the Aβ (25-35) (10 μM)-induced neuronal cell death, as assessed by a 3-[4,5-dimethyIthiazole-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and the number of apoptotic nuclei, evidenced by Hoechst 33342 staining. CB (50 μg/μl) inhibited glutamate release into medium induced by 10 μM Aβ, (25-35) which was measured by HPLC. Pretreatment of CB (50 μg/μl) inhibited 10μM Aβ (25-35)-induced elevation of cytosolic calcium concentration ([Ca2+]c), which was measured by a fluorescent dye, fluo-4 AM, and generation of reactive oxygen species. These results suggest that CB prevents Aβ (25-35)-induced neuronal ell damage in vitro.