• Journal of Physiology & Pathology in Korean Medicine
• /
• v.34 no.2
• /
• pp.81-87
• /
• 2020

Cognitive impairment is symptoms of dementia, a degenerative brain disease that is drawing attention in a rapidly aging society. This study was conducted to investigate the improvement of cognitive function of Leonurus japonicus on scopolamine-induced memory impairment in mice and the effect and mechanism of memory recovery. In vivo studies were conducted on mice orally pretreated with L. japonicus in doses of 50, 100 and 200 mg/kg (p.o.) and scopolamine (1 mg/kg, i.p.) were injected 30 min before the behavioral task. Antioxidant activity was assessed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and acetylcholinesterase (AChE) inhibition activity evaluated by Ellman's method. In behavior studies showed that L. japonicus has an improved the memory of scopolamine-treated mice in Y-maze, passive avoidance and Morris water maze test. In addition, L. japonicus was also exerted free radical scavenging activity and inhibited acetyl cholinesterase activity. These results suggest that L. japonicus improves short-term and long-term memory in scopolamine-induced memory decline model and prevents scopolamine-induced memory impairments through in reduced oxidative stress and acetyl cholinesterase inhibition effect. Thus, L. japonicus is related to functional medicinal materials for prevention and treatment of human dementia patients.

• Journal of Korean Society for Atmospheric Environment
• /
• v.25 no.4
• /
• pp.325-338
• /
• 2009

National parks provide recreation, health, and science to human being. The provision of beautiful landscape view of the national park improves an economic and social phase of a nation. However, visibility impairment frequently occurred in the national park area of Gyeongju. The purpose of this study is to investigate the physical and the chemical characteristics of visibility reduction observed at the national park area of Gyeongju. Optical, chemical, meteorological characteristics and scenic monitoring were performed at the visibility monitoring station of Gyeongju University located at the Seoak section of Gyeongju national park from April 28 to May 9, 2008. Light extinction, light scattering, and light absorption coefficients were continuously measured using a transmissometer, a nephelometer, and an aethalometer, respectively. In order to investigate the impact of aerosol chemistry on visibility impairment, size-resolved aerosols were collected at intervals of 2-hour (from 8 A.M. to 6 P.M.) and 14-hour (from 6 P.M. to 8 A.M.) interval each sampling day. The average light extinction coefficient and the average visual range were measured to be $270{\pm}135\;Mm^{-1}$ and $14.5{\pm}6.3\;km$ during the intensive monitoring period, respectively. It was revealed that sulfate particle was the largest contributor to the light extinction under hazy condition. Organic mass accounted for about 26% of the average light extinction. The mass extinction efficiencies for $PM_{1.0}$, $PM_{2.5}$, and $PM_{10}$ were estimated to be 9.0, 4.7, and $2.7\;m^2\;g^{-1}$ under the consideration of water growth function of hygroscopic aerosols, respectively.

• The Journal of Korean Medicine
• /
• v.21 no.2
• /
• pp.25-36
• /
• 2000

Objectives : This study demonstrates the effects of Daejo-hwan on learning and memory impairment induced by L-NAME (75 mg/kg) treatment and on cerebral ischemic damage induced by middle cerebral artery (MCA) occlusion in rats. Methods : Daejo-hwan emulsion (73.3 mg/100 g/l ml) was administered to rats along a timed study schedule. The Moms water maze was used for learning and memory test of the rats. The MCA was occluded by using the intraluminal thread method. The brain slices were stained by 2 % triphenyl tetrazolium chloride (TTC) and 1 % cresyl violet solution. Infarct size, neuron cell number and size in penumbra was measured by using computer image analysis system. Results : 1. The escape latency of the Daejo-hwan treated group decreased significantly with respect to the control group. 2.The memory score of the Daejo-hwan treated group showed increase tendency, And the swimming distance was not different between the normal, the control, and the Daejo-hwan treated group. 3. The infarct size of the Daejo-hwan treated group decreased significantly with respect to the control group. 4. The total infarct volume of the Daejo-hwan treated group showed decrease tendency. And the brain edema index of the Daejo-hwan treated group decreased significantly with respect to the control group. 5. The neuron cell number and cell size in penumbra of the Daejo-hwan treated group increased significantly with respect to the control group. Conclusions : According to the above results, it is supposed that Daejo-hwan is clinically applicable to the vascular dementia.

• The Korean Journal of Physiology and Pharmacology
• /
• v.25 no.4
• /
• pp.281-296
• /
• 2021

The beneficial effects of hypoxic preconditioning are abolished in the diabetes. The present study was designed to investigate the protective effects and mechanisms of repeated episodes of whole body hypoxic preconditioning (WBHP) in db/db mice. The protective effects of preconditioning were explored on diabetes-induced vascular dysfunction, cognitive impairment and ischemia-reperfusion (IR)-induced increase in myocardial injury. Sixteen-week old db/db (diabetic) and C57BL/6 (non-diabetic) mice were employed. There was a significant impairment in cognitive function (Morris Water Maze test), endothelial function (acetylcholine-induced relaxation in aortic rings) and a significant increase in IR-induced heart injury (Langendorff apparatus) in db/db mice. WBHP stimulus was given by exposing mice to four alternate cycles of low (8%) and normal air O₂ for 10 min each. A single episode of WBHP failed to produce protection; however, two and three episodes of WBHP significantly produced beneficial effects on the heart, brain and blood vessels. There was a significant increase in the levels of brain-derived neurotrophic factor (BDNF) and nitric oxide (NO) in response to 3 episodes of WBHP. Moreover, pretreatment with the BDNF receptor, TrkB antagonist (ANA-12) and NO synthase inhibitor (L-NAME) attenuated the protective effects imparted by three episodes of WBHP. These pharmacological agents abolished WBHP-induced restoration of p-GSK-3β/GSK-3β ratio and Nrf2 levels in IR-subjected hearts. It is concluded that repeated episodes of WHBP attenuate cognitive impairment, vascular dysfunction and enhancement in IR-induced myocardial injury in diabetic mice be due to increase in NO and BDNF levels that may eventually activate GSK-3β and Nrf2 signaling pathway to confer protection.

• Biomolecules & Therapeutics
• /
• v.27 no.1
• /
• pp.71-77
• /
• 2019

Previous studies have shown that spinosin was implicated in the modulation of sedation and hypnosis, while its effects on learning and memory deficits were rarely reported. The aim of this study is to investigate the effects of spinosin on the improvement of cognitive impairment in model mice with Alzheimer's disease (AD) induced by $A{\beta}_{1-42}$ and determine the underlying mechanism. Spontaneous locomotion assessment and Morris water maze test were performed to investigate the impact of spinosin on behavioral activities, and the pathological changes were assayed by biochemical analyses and histological assay. After 7 days of intracerebroventricular (ICV) administration of spinosin ($100{\mu}g/kg/day$), the cognitive impairment of mice induced by $A{\beta}_{1-42}$ was significantly attenuated. Moreover, spinosin treatment effectively decreased the level of malondialdehyde (MDA) and $A{\beta}_{1-42}$ accumulation in hippocampus. $A{\beta}_{1-42}$ induced alterations in the expression of brain derived neurotrophic factor (BDNF) and B-cell lymphoma-2 (Bcl-2), as well as inflammatory response in brain were also reversed by spinosin treatment. These results indicated that the ameliorating effect of spinosin on cognitive impairment might be mediated through the regulation of oxidative stress, inflammatory process, apoptotic program and neurotrophic factor expression,suggesting that spinosin might be beneficial to treat learning and memory deficits in patients with AD via multi-targets.

• Journal of Oriental Neuropsychiatry
• /
• v.29 no.4
• /
• pp.207-221
• /
• 2018

Objectives: The objective of this study was to observe the anti-amnesic effects of Yukmijihwang-tang (YMJHT), on the scopolamine (Sco)-induced memory impairment in C57BL/6 mice through its favorable acetylcholine (ACh). Also, to observe acetylcholinesterase (AChE) activity, Choline acetyltransferase (ChAT) mRNA expressions, and antioxidant effect. Methods: Six groups, with a total of 20 normal and 100 Sco treated mice were selected based on their body weights after 1 week of acclimatization, were used in this study as follows. Half of the mice in each group were used for passive avoidance task tests and hippocampus ACh content, AChE activity and ChAT mRNA expression measurement, and the remaining half in each group used for Morris water maze test and measurement of cerebral antioxidant defense system. Results: Amnesia due to AChE activations and destroyed cerebral cortex antioxidant defense systems were markedly and dose-dependently inhibited after 28 days of continuous oral pre-treatment with YMJHT 400, 200 and 100 mg/kg, respectively. The overall effects of YMJHT 400 mg/kg were similar to those of tacrine 10 mg/kg. Conclusions: Based on the results, it was established that oral administration of YMJHT favorably alleviates Sco-induced memory impairment, through preservation of ACh, mediated by up-regulation of ChAT mRNA expressions and related AChE inhibition and augmentation of cerebral antioxidant defense system, at least in a condition of this experiment. The overall effects of YMJHT 400 mg/kg were similar to those of tacrine 10 mg/kg.

• Journal of Korean Academy of Nursing
• /
• v.49 no.3
• /
• pp.317-328
• /
• 2019

Purpose: The purpose of this study was to identify the effect of ghrelin on memory impairment in a rat model of vascular dementia induced by chronic cerebral hypoperfusion. Methods: Randomized controlled groups and the posttest design were used. We established the representative animal model of vascular dementia caused by bilateral common carotid artery occlusion and administered $80{\mu}g/kg$ ghrelin intraperitoneally for 4 weeks. First, behavioral studies were performed to evaluate spatial memory. Second, we used molecular biology techniques to determine whether ghrelin ameliorates the damage to the structure and function of the white matter and hippocampus, which are crucial to learning and memory. Results: Ghrelin improved the spatial memory impairment in the Y-maze and Morris water maze test. In the white matter, demyelination and atrophy of the corpus callosum were significantly decreased in the ghrelin-treated group. In the hippocampus, ghrelin increased the length of hippocampal microvessels and reduced the microvessels pathology. Further, we confirmed angiogenesis enhancement through the fact that ghrelin treatment increased vascular endothelial growth factor (VEGF)-related protein levels, which are the most powerful mediators of angiogenesis in the hippocampus. Conclusion: We found that ghrelin affected the damaged myelin sheaths and microvessels by increasing angiogenesis, which then led to neuroprotection and improved memory function. We suggest that further studies continue to accumulate evidence of the effect of ghrelin. Further, we believe that the development of therapeutic interventions that increase ghrelin may contribute to memory improvement in patients with vascular dementia.

• Nutrition Research and Practice
• /
• v.16 no.2
• /
• pp.173-193
• /
• 2022

BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is one of the most representative neurodegenerative disease mainly caused by the excessive production of amyloid beta (Aβ). Several studies on the antioxidant activity and protective effects of Populus tomentiglandulosa (PT) against cerebral ischemia-induced neuronal damage have been reported. Based on this background, the present study investigated the protective effects of PT against cognitive impairment in AD. MATERIALS/METHODS: We orally administered PT (50 and 100 mg/kg/day) for 14 days in an Aβ_25-35-induced mouse model and conducted behavioral experiments to test cognitive ability. In addition, we evaluated the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum and measured the production of lipid peroxide, nitric oxide (NO), and reactive oxygen species (ROS) in tissues. RESULTS: PT treatment improved the space perceptive ability in the T-maze test, object cognitive ability in the novel object recognition test, and spatial learning/long-term memory in the Morris water-maze test. Moreover, the levels of AST and ALT were not significantly different among the groups, indicating that PT did not show liver toxicity. Furthermore, administration of PT significantly inhibited the production of lipid peroxide, NO, and ROS in the brain, liver, and kidney, suggesting that PT protected against oxidative stress. CONCLUSIONS: Our study demonstrated that administration of PT improved Aβ_25-35-induced cognitive impairment by regulating oxidative stress. Therefore, we propose that PT could be used as a natural agent for AD improvement.

• Journal of Pharmacopuncture
• /
• v.27 no.2
• /
• pp.70-81
• /
• 2024

Objectives: Cognitive impairments, ranging from mild to severe, adversely affect daily functioning, quality of life, and work capacity. Despite significant efforts in the past decade, more than 200 promising drug candidates have failed in clinical trials. Herbal remedies are gaining interest as potential treatments for dementia due to their long history and safety, making them valuable for drug development. This review aimed to examine the mechanisms behind the effect of Polygonum multiflorum on cognitive function. Methods: This study focused primarily on the effects of Polygonum multiflorum and its chemical constituents on cognitive behavioral outcomes including the Morris water maze, the passive avoidance test, and the Y maze, as well as pathogenic targets of cognitive impairment and Alzheimer's disease (AD) like amyloid deposition, amyloid precursor protein, tau hyperphosphorylation, and cognitive decline. Additionally, a thorough evaluation of the mechanisms behind Polygonum multiflorum's impact on cognitive function was conducted. We reviewed the most recent data from preclinical research done on experimental models, particularly looking at Polygonum multiflorum's effects on cognitive decline and AD. Results: According to recent research, Poligonum multiflorum and its bioactive components, stilbene, and emodin, influence cognitive behavioral results and regulate the pathological target of cognitive impairment and AD. Their mechanisms of action include reducing oxidative and mitochondrial damage, regulating neuroinflammation, halting apoptosis, and promoting increased neurogenesis and synaptogenesis. Conclusion: This review serves as a comprehensive compilation of current experiments on AD and other cognitive impairment models related to the therapeutic effects of Polygonum multiflorum. We believe that these findings can serve as a basis for future clinical trials and have potential applications in the treatment of human neurological disorders.

• Nutrition Research and Practice
• /
• v.18 no.4
• /
• pp.464-478
• /
• 2024

BACKGROUND/OBJECTIVES: Chronic alcohol consumption causes oxidative stress in the body, which may accumulate excessively and cause a decline in memory; problem-solving, learning, and exercise abilities; and permanent damage to brain structure and function. Consequently, chronic alcohol consumption can cause alcohol-related diseases. MATERIALS/METHODS: In this study, the protective effects of Phyllostachys edulis (Carrière) J. Houz (PE) against alcohol-induced neuroinflammation and cognitive impairment were evaluated using a mouse model. Alcohol (16%, 5 g/kg/day for 6 weeks) and PE (100, 250, and 500 mg/kg/day for 21 days) were administered intragastrically to mice. RESULTS: PE showed a protective effect against memory deficits and cognitive dysfunction caused by alcohol consumption, confirmed through behavioral tests such as the T-maze, object recognition, and Morris water maze tests. Additionally, PE attenuated oxidative stress by reducing lipid oxidation, nitric oxide, and reactive oxygen species levels in the mice's brains, livers, and kidneys. Improvement of neurotrophic factors and downregulation of apoptosis-related proteins were confirmed in the brains of mice fed low and medium concentrations of PE. Additionally, expression of antioxidant enzyme-related proteins GPx-1 and SOD-1 was enhanced in the liver of PE-treated mice, related to their inhibitory effect on oxidative stress. CONCLUSION: This suggests that PE has both neuroregenerative and antioxidant effects. Collectively, these behavioral and histological results confirmed that PE could improve alcohol-induced cognitive deficits through brain neurotrophic and apoptosis protection and modulation of oxidative stress.