• Nutrition Research and Practice
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• 제11권1호
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• pp.25-32
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• 2017

BACKGROUND/OBJECTIVES: Stress-induced cognitive impairment is related to the suppression of hippocampal neurogenesis that results from an increase of oxidative stress. Therefore, the aim of this study was to investigate the effects of administration of a blueberry drink, having a high antioxidant power, on the cognitive performance of adult rats exposed to chronic mild stress. MATERIALS/METHODS: Twelve-week-old male Sprague-Dawley rats (n = 48) were randomly divided into four groups: control (CO), stress (ST), control + 5% blueberry drink (CO + B), and stress + 5% blueberry drink (ST + B). After eight weeks, the cognitive performance was assessed using a multiple T-maze water test. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and ascorbic acid were measured in the brain, and catecholamine concentrations were measured in plasma. RESULTS: The brain weights of the rats from the ST and ST + B groups were significantly lower than those of the rats from the CO and CO + B groups. The cognitive performance of the ST group was impaired when compared to that of the CO group. This impairment was significantly improved by the blueberry drink supplementation (P < 0.05). The brain SOD and CAT concentrations were not influenced by the stress or by the blueberry drink. However, the brain levels of GPx and ascorbic acid were significantly lower in the ST group than those in the CO group and were increased by the blueberry drink supplementation. The plasma catecholamine concentrations were affected by chronic mild stress and by the blueberry drink. The plasma norepinephrine and dopamine concentrations were decreased by the chronic stress and improved by the blueberry drink supplementation. The plasma epinephrine level was only influenced by the stress. CONCLUSION: These findings suggest that the blueberry drink may protect against the cognitive impairment induced by chronic mild stress.

• BMB Reports
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• 제44권12호
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• pp.793-798
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• 2011

Recently, pluripotency induction or cellular reprogramming by introducing critical transcription factors has been extensively studied, but has been demonstrated only in vitro. Based on reports that Oct4 is critically involved in transforming neural stem cells into pluripotent cells, we used the lentiviral vector to introduce the Oct4 gene into the hippocampal dentate gyrus (DG) of adult mice. We examined whether this manipulation led to cellular or behavioral changes, possibly through processes involving the transformation of NS cells into pluripotent cells. The Oct4 lentivirus-infused group and the green fluorescent protein lentivirus-infused group showed a similar thickness of the DG and a comparable level of synaptophysin expression in the DG. Furthermore, our behavioral analyses did not show any differences between the groups concerning exploratory activity, anxiety, or memory abilities. This first trial for pluripotency induction in vivo, despite negative results, provides implications and information for future studies on in vivo cellular reprogramming.

• Biomolecules & Therapeutics
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• 제28권1호
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• pp.74-82
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• 2020

Alzheimer's disease (AD) is a progressive and most frequently diagnosed neurodegenerative disorder. However, there is still no drug preventing the progress of this disorder. β-Amyrin, an ingredient of the surface wax of tomato fruit and dandelion coffee, is previously reported to ameliorate memory impairment induced by cholinergic dysfunction. Therefore, we tested whether β-amyrin can prevent AD-like pathology. β-Amyrin blocked amyloid β (Aβ)-induced long-term potentiation (LTP) impairment in the hippocampal slices. Moreover, β-amyrin improved Aβ-induced suppression of phosphatidylinositol-3-kinase (PI3K)/Akt signaling. LY294002, a PI3K inhibitor, blocked the effect of β-amyrin on Aβ-induced LTP impairment. In in vivo experiments, we observed that β-amyrin ameliorated object recognition memory deficit in Aβ-injected AD mice model. Moreover, neurogenesis impairments induced by Aβ was improved by β-amyrin treatment. Taken together, β-amyrin might be a good candidate of treatment or supplement for AD patients.

• Journal of Ginseng Research
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• 제47권6호
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• pp.735-742
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• 2023

Background: Gintonin is a new material of ginseng that acts through the ginseng-derived lysophosphatidic acid (LPA) receptor ligand. The gintonin-enriched fraction (GEF) inhibits amyloid plaque accumulation in the cortex and hippocampus, improves cognitive dysfunction by increasing acetylcholine levels, and promoted hippocampal neurogenesis in an animal model of Alzheimer's disease. We evaluated the effect of the GEF on the cognitive performance of subjects with subjective memory impairment (SMI). Methods: In this eight-week, randomized, assessor- and participant-blinded, placebo-controlled study, participants with SMI were assigned to three groups receiving placebo, GEF 300 mg/day or GEF 600 mg/day. The Korean versions of the Alzheimer's Disease Assessment Scale (K-ADAS), Mini-Mental State Examination (K-MMSE), and Stroop color-word test (K-SCWT) were also evaluated along with the safety profiles. Results: One hundred thirty-six participants completed the study. After eight weeks, we analyzed intergroup differences in primary or secondary outcome score changes. When we compared the GEF group with the placebo group, we observed significant improvements in the K-ADAS and K-SCWT scores. The GEF group did not show a significant improvement in K-MMSE and BDI scores compared to the placebo group. No adverse events were observed in the gintonin and placebo groups for eight weeks. Conclusion: The GEF is safe and effective in improving subjective cognitive impairment related to both the K-ADAS and K-SCWT in this study. However, further large-scale and randomized controlled studies are warranted to secure other cognitive function tests besides the K-ADAS and K-SCWT, and to confirm the findings of the current study.

• Journal of Ginseng Research
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• 제42권4호
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• pp.401-411
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• 2018

Longevity in medicine can be defined as a long life without mental or physical deficits. This can be prevented by Alzheimer's disease (AD). Current conventional AD treatments only alleviate the symptoms without reversing AD progression. Recent studies demonstrated that Panax ginseng extract improves AD symptoms in patients with AD, and the two main components of ginseng might contribute to AD amelioration. Ginsenosides show various AD-related neuroprotective effects. Gintonin is a newly identified ginseng constituent that contains lysophosphatidic acids and attenuates AD-related brain neuropathies. Ginsenosides decrease amyloid ${\beta}$-protein ($A{\beta}$) formation by inhibiting ${\beta}$- and ${\gamma}$-secretase activity or by activating the nonamyloidogenic pathway, inhibit acetylcholinesterase activity and $A{\beta}$-induced neurotoxicity, and decrease $A{\beta}$-induced production of reactive oxygen species and neuro-inflammatory reactions. Oral administration of ginsenosides increases the expression levels of enzymes involved in acetylcholine synthesis in the brain and alleviates $A{\beta}$-induced cholinergic deficits in AD models. Similarly, gintonin inhibits $A{\beta}$-induced neurotoxicity and activates the nonamyloidogenic pathway to reduce $A{\beta}$ formation and to increase acetylcholine and choline acetyltransferase expression in the brain through lysophosphatidic acid receptors. Oral administration of gintonin attenuates brain amyloid plaque deposits, boosting hippocampal cholinergic systems and neurogenesis, thereby ameliorating learning and memory impairments. It also improves cognitive functions in patients with AD. Ginsenosides and gintonin attenuate AD-related neuropathology through multiple routes. This review focuses research demonstrating that ginseng constituents could be a candidate as an adjuvant for AD treatment. However, clinical investigations including efficacy and tolerability analyses may be necessary for the clinical acceptance of ginseng components in combination with conventional AD drugs.

• Laboraroty Animal Research
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• 제34권4호
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• pp.239-247
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• 2018

Bacopa monnieri is a medicinal plant with a long history of use in Ayurveda, especially in the treatment of poor memory and cognitive deficits. In the present study, we hypothesized that Bacopa monnieri extract (BME) can improve memory via increased cell proliferation and neuroblast differentiation in the dentate gyrus. BME was administered to 7-week-old mice once a day for 4 weeks and a novel object recognition memory test was performed. Thereafter, the mice were euthanized followed by immunohistochemistry analysis for Ki67, doublecortin (DCX), and phosphorylated cAMP response element-binding protein (CREB), and western blot analysis of brain-derived neurotrophic factor (BDNF). BME-treated mice showed moderate increases in the exploration of new objects when compared with that of familiar objects, leading to a significant higher discrimination index compared with vehicle-treated mice. Ki67 and DCX immunohistochemistry showed a facilitation of cell proliferation and neuroblast differentiation following the administration of BME in the dentate gyrus. In addition, administration of BME significantly elevated the BDNF protein expression in the hippocampal dentate gyrus, and increased CREB phosphorylation in the dentate gyrus. These data suggest that BME improves novel object recognition by increasing the cell proliferation and neuroblast differentiation in the dentate gyrus, and this may be closely related to elevated levels of BDNF and CREB phosphorylation in the dentate gyrus.