Publications by authors named "Im Seop Choi"

Alzheimer's disease (AD) is the most prevalent cause of dementia in the elderly people. The disease is pathologically characterized by extracellular deposition of beta-amyloid peptide (Aβ), cholinergic neurodegeneration and elevation of acetylcholine esterase (AChE) activity in the affected regions. In this study, we investigated the effects of obovatol on memory dysfunction, which was caused by scopolamine.

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Background: Neuroinflammation is important in the pathogenesis and progression of Alzheimer disease (AD). Previously, we demonstrated that lipopolysaccharide (LPS)-induced neuroinflammation caused memory impairments. In the present study, we investigated the possible preventive effects of 4-O-methylhonokiol, a constituent of Magnolia officinalis, on memory deficiency caused by LPS, along with the underlying mechanisms.

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Etiology of Alzheimer's disease (AD) is obscure, but neuroinflammation and accumulation of β-amyloid (Aβ) are implicated in pathogenesis of AD. We have shown anti-inflammatory and neurotrophic properties of obovatol, a biphenolic compound isolated from Magnolia obovata. In this study, we examined the effect of obovatol on cognitive deficits in two separate AD models: (i) mice that received intracerebroventricular (i.

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Neuroinflammation and accumulation of β-amyloid are critical pathogenic mechanisms of Alzheimer's disease (AD). In the previous study, we have shown that systemic lipopolysaccharide (LPS) caused neuroinflammation with concomitant increase in β-amyloid and memory impairments in mice. In an attempt to investigate anti-neuroinflammatory properties of obovatol isolated from Magnolia obovata, we administered obovatol (0.

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Accumulations of amyloid-β (Aβ) and oxidative damage are critical pathological mechanisms in the development of Alzheimer's disease (AD). We previously found that 4-O-methylhonokiol, a compound extracted from Magnolia officinalis, improved memory dysfunction in Aβ-injected and presenilin 2 mutant mice through the reduction of accumulated Aβ. To investigate mechanisms of the reduced Aβ accumulation, we examined generation, degradation, efflux and aggregation of Aβ in Swedish AβPP AD model (AβPPsw) mice pre-treated with 4-O-methylhonokiol (1.

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Presenilin 2 (PS2) mutation increases Aβ generation and neuronal cell death in the brains of Alzheimer disease (AD) patients. In a previous study, we showed that increased oxidative damage and activation of extracellular signal-regulated kinase (ERK) were associated with Aβ generation and neuronal cell death in neuronal cells expressing mutant PS2. In this study, we show that oral treatment with 4-O-methylhonokiol, a novel compound isolated from Magnolia officinalis, for 3 months (1.

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Previously, we found that obovatol, a lignan compound isolated from Magnolia officinalis, has anti-cancer, anti-inflammatory, and anxiolytic effects. Recent studies showed that honokiol, magnolol, and 4-O-methylhonokiol, lignin compounds isolated from the Magnolia family have neurotrophic activity. In this study, we examined whether or not obovatol also exhibits neurite-promoting effects on rat embryonic neuronal cells.

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Oxidative stress induced neuronal cell death by accumulation of β-amyloid (Aβ) is a critical pathological mechanism of Alzheimer's disease (AD). Intracerebroventrical infusion of Aβ(1-42) (300 pmol/day per mouse) for 14 days induced neuronal cell death and memory impairment, but pre-treatment of 4-O-methylhonokiol (4-O-MH), a novel compound extracted from Magnolia officinalis for 3 weeks (0.2, 0.

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Amyloid beta (Abeta)-induced neurotoxicity is a major pathological mechanism of Alzheimer disease (AD). In this study, we investigated the inhibitory effect of l-theanine, a component of green tea (Camellia sinensis), on Abeta(1-42)-induced neuronal cell death and memory impairment. Oral treatment of l-theanine (2 and 4 mg/kg) for 5 weeks in the drinking water of mice, followed by injection of Abeta(1-42) (2 microg/mouse, icv), significantly attenuated Abeta(1-42)-induced memory impairment.

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Compounds isolated from Magnolia officinalis such as magnolol, honokiol and obovatol exhibit several pharmacological effects on CNS including depressant, anxiolytic and anticonvulsant effects, as well as neuroprotective effects against chemical and heat damages. Recently, honokiol was found to have a neurotrophic effect in fetal rat cortical neurons. In the present study, we show that 4-O-methylhonokiol, a novel compound from Magnolia officinalis, promotes neurite outgrowth in a concentration- dependent manner in rat embryonic neuronal cells.

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