• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.177-181
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• 2015

The subfornical organ (SFO) is one of circumventricular organs characterized by the lack of a normal blood brain barrier. The SFO neurons are exposed to circulating glutamate ($60{\sim}100{\mu}M$), which may cause excitotoxicity in the central nervous system. However, it remains unclear how SFO neurons are protected from excitotoxicity caused by circulating glutamate. In this study, we compared the glutamate-induced whole cell currents in SFO neurons to those in hippocampal CA1 neurons using the patch clamp technique in brain slice. Glutamate ($100{\mu}M$) induced an inward current in both SFO and hippocampal CA1 neurons. The density of glutamate-induced current in SFO neurons was significantly smaller than that in hippocampal CA1 neurons (0.55 vs. 2.07 pA/pF, p<0.05). To further identify the subtype of the glutamate receptors involved, the whole cell currents induced by selective agonists were then compared. The current densities induced by AMPA (0.45 pA/pF) and kainate (0.83 pA/pF), non-NMDA glutamate receptor agonists in SFO neurons were also smaller than those in hippocampal CA1 neurons (2.44 pA/pF for AMPA, p<0.05; 2.34 pA/pF for kainate, p< 0.05). However, the current density by NMDA in SFO neurons was not significantly different from that of hippocampal CA1 neurons (1.58 vs. 1.47 pA/pF, p>0.05). These results demonstrate that glutamate-mediated action through non-NMDA glutamate receptors in SFO neurons is smaller than that of hippocampal CA1 neurons, suggesting a possible protection mechanism from excitotoxicity by circulating glutamate in SFO neurons.

• BMB Reports
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• v.43 no.4
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• pp.225-232
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• 2010

Parkinson's Disease (PD) is a common neurodegenerative disease characterized by the progressive degeneration of nigrostriatal dopaminergic (DA) neurons. Although the causative factors of PD remain elusive, many studies on PD animal models or humans suggest that glial activation along with neuroinflammatory processes contribute to the initiation or progression of PD. Additionally, several groups have proposed that dysfunction of the blood-brain barrier (BBB) combined with infiltration of peripheral immune cells play important roles in the degeneration of DA neurons. However, these neuroinflammatory events have only been investigated separately, and the issue of whether these phenomena are neuroprotective or neurotoxic remains controversial. We here review the current knowledge regarding the functions of these neuroinflammatory processes in the brain. Finally, we describe therapeutic strategies for the regulation of neuroinflammation with the goal of improving the symptoms of PD.

• Biomedical Science Letters
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• v.11 no.1
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• pp.31-36
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• 2005

To evaluate the magnetic resonance imaging and electron microscopic findings of the hyperacute stage of cerebral fat embolism in cats and the time needed for the development of vasogenic edema. Magnetic resonance imaging was performed at 30 minutes (group 1, n=9) and at 30 minutes and 1, 2, 4, and 6 hours after embolization with triolein (group 2, n= 10). As a control for group 2, the same acquisition was obtained after embolization with polyvinyl alcohol particles (group 3, n=5). Electron microscopic examination was done in all cats. In group 1, the lesions were iso- or slightly hyperintense on T2-weighted (T2W) and diffusion-weighted (DWIs) images, hypointense on the apparent diffusion coefficient (ADC) map image, and markedly enhanced on the gadolinium-enhanced T1-weighted images (Gd-T1WIs). In group 2 at 30 minutes, the lesions were similar to those in group 1. Thereafter, the lesions became more hyperintense on T2WIs and DWIs and more hypoinfense on the ADC map image. In group 3, the lesions showed mild hyperintensity on T2WIs at 6 hours but hypointensity on the ADC map image from 30 minutes, with a tendency toward a greater decrease over time. Electron microscopic findings revealed discontinuity of the capillary endothelial wall, perivascular and interstitial edema, and swelling of glial and neuronal cells in groups 1 and 2. The lesions were hyperintense on T2WIs and DWIs, hypointense on the ADC map image, and enhanced on Gd-T1WIs. On electron microscopy, the lesions showed cytotoxic and vasogenic edema with disruption of the blood-brain barrier.

• Korean Journal of Bronchoesophagology
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• v.16 no.1
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• pp.33-38
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• 2010

Titania nanomaterials are widely used as cosmetics and dyes, however the impacts on human health are uncertain, We investigated the biodistribution of inhaled titania nanoparticles in rats, Methods Eight weeks-old SD rats were intubated and inhaled with 3 mg titania nanoparticles, twice a week, for 2 weeks, After inhalation, the rats were sacrificed and tissues or heart, lung. intestine, brain, and liver were obtained, We investigated the tissues with optical microscope (OM), transmission electron microscope (EM), scanning EM, And to analyze titania concentration of each tissue, we lysed the tissues with radioimmunoprecipitation assay (RlPA) lysis buffer or acid. Results Granulation tissues in lung were confirmed on the optical microscope, however the other organs had no abnormalities in OM images, In EM images, the rats which inhaled titania nanoparticles showed calcium deposition at heart, brain, and intestine, Titania concentration in lung was increased on the inhaled rat sacrificed I month after last exposure. Conclusion Inhaled titania nanoparticles is thought to be deposited and make inflammatory reaction in lung, and the deposition was not efficiently cleared over a month. However inhaled titania nanoparticles may rarely pass through the alveolus-blood barrier and distribute to other organs of the bod.

• YAKHAK HOEJI
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• v.51 no.6
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• pp.463-468
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• 2007

Chong Myung Tang is consisted of three medicinal herbs (Acori Graminei Rhizoma, Polygalae Radix and Hoelen cum Radix). It has been used as a medicine for the purpose of learning and memory improvement. In this paper, Chong Myung Tang was screened the biological activities for Alzheimer's disease. The extract (70% ethanol) of Acari Graminei Rhizoma (1 mg/ml) showed that acetylcholinesterase (AChE) and amyloid beta ($A{\beta}$) peptide aggregation inhibitory potency are 43.1% and 76.5%, respectively. The extract of Polygalae Radix showed inhibitory activity against $A{\beta}_{1-42}$ peptide aggregation (51.5%). To predict the drug-likeness, oral absorption ability; blood-brain barrier (BBB) penetraion rate, mutagenecity and carcinogenicity; in silico screening was performed against 16 compounds in the three medicinal herbs. According to the results, all compounds have appropriate chemical structures as medicines. The six compounds in Acori Graminei Rhizoma and the five compounds in Hoelen cum Radix showed excellent oral absorption rate and BBB penetration rate. The four compounds in Polygalae Radix showed excellent oral absorption rate, but their BBB penetration was presented low rate. And, the extract of Hoelen cum Radix didn't show AChE and $A{\beta}_{1-42}$ peptide aggregation inhibitory activities in vitro. Therefore, their activity in brain may be other mechanism. According to all of the results, in silico prediction technology is convenient and effective to determine biological active compounds in medicinal herbs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.6
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• pp.309-318
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• 2020

Besides respiratory infection, COVID-19 has many neurological symptoms not only loss of smell and taste but also fatigue and brain fog. But it is a challenge to treat the neurological symptoms especially of anosmia and ageusia. In order to search for the therapeutic methods, the geographical diversity and pathological mechanisms of the COVID-19 and two symptoms were investigated from the latest clinical studies. Because the environmental conditions of the monsoon climate zone of East Asia and the Mediterranean and Oceanic climate zone of Italy, Britain, United States and tropical Brazil are different, each of diverse etiology and internal milieu should be considered differently in the treatment. SARS-CoV-2 exhibits the dampness-like characteristics and the olfactory and gustatory disorders are particularly more common than other flu or cold. and it tends to show features of damaging the lung qi of olfaction and heart-spleen qi of gustation. The mechanisms of olfactory and gustatory loss are various according to precursory, inflammatory, non-inflammatory and sequelar forms, so the therapeutic method should be designed for each period and pathology. If the process of inflammation arises from nasal and respiratory, olfactory epithelium to the central nervous structure by way of blood brain barrier, the treatment should be corresponded with the stage and depth of pathogen place. And if the olfactory loss is asymptomatic or in the initial stage, it can be applied intranasal topical scent therapy to relieve temporary locking of qi movement, but maybe also used in parallel together with herbs of relieving dampness toxin latent in the lung parenchyma.

• Journal of Ginseng Research
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• v.46 no.5
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• pp.700-709
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• 2022

Background: Ginsenoside Rd is a natural compound with promising neuroprotective effects. However, the underlying mechanisms are still not well-understood. In this study, we explored whether ginsenoside Rd exerts protective effects on cerebral endothelial cells after oxygen-glucose deprivation/reoxygenation (OGD/R) treatment and its potential docking proteins related to the underlying regulations. Method: Commercially available primary human brain microvessel endothelial cells (HBMECs) were used for in vitro OGD/R studies. Cell viability, pyroptosis-associated protein expression and tight junction protein degradation were evaluated. Molecular docking proteins were predicted. Subsequent surface plasmon resonance (SPR) technology was utilized for validation. Flow cytometry was performed to quantify caspase-1 positive and PI positive (caspase-1+/PI+) pyroptotic cells. Results: Ginsenoside Rd treatment attenuated OGD/R-induced damage of blood-brain barrier (BBB) integrity in vitro. It suppressed NLRP3 inflammasome activation (increased expression of NLRP3, cleaved caspase-1, IL-1β and GSDMD-N terminal (NT)) and subsequent cellular pyroptosis (caspase-1+/PI + cells). Ginsenoside Rd interacted with SLC5A1 with a high affinity and reduced OGD/R-induced sodium influx and potassium efflux in HBMECs. Inhibiting SLC5A1 using phlorizin suppressed OGD/R-activated NLRP3 inflammasome and pyroptosis in HBMECs. Conclusion: Ginsenoside Rd protects HBMECs from OGD/R-induced injury partially via binding to SLC5A1, reducing OGD/R-induced sodium influx and potassium efflux, thereby alleviating NLRP3 inflammasome activation and pyroptosis.

• Herbal Formula Science
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• v.31 no.3
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• pp.145-156
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• 2023

Objectives : This study aimed to select candidate herbal medicines to be used in preclinical studies of cerebral infarction using the network pharmacology research method. Methods : Oral bioavailability (OB), drug likeness (DL), Caco-2, and blood-brain barrier (BBB) permeability were employed in this study's network pharmacology analysis method to choose compounds with potential efficacy. The following formulas were utilized for the values of each variable used in this study: OB ≥ 20%, DL ≥ 0.18, Caco-2 ≥ 0, and BBB ≥ -0.3. The relationships between target proteins and diseases that are assumed to be involved in the chosen bioavailable chemicals were built in a network manner using the aforementioned factors, and proteins thought to play a significant role were identified. Results : Sudan III was obtained as a result of selecting compounds related to ischemic stroke in consideration of pharmacokinetic characteristics such as digestion and absorption and practicality using the TCMSP database. Medicinal herbs Gardeniae Fructus (GF) contains sudan III, and it was confirmed that compounds in GF were highly related to brain diseases, and the mechanism involved through the KEGG pathway was confirmed. GF, which has sudan III related to ischemic stroke and is also involved in other neurological diseases, is expected to be used for ischemic stroke treatment. Conclusions : GF has been predicted to have potential for ischemic stroke treatment, and can be used for future preclinical studies.

• Applied Microscopy
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• v.34 no.4
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• pp.231-239
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• 2004

Cerebral microvessel endothelial cells that form blood-brain barrier (BBB) have tight junction for maintaining brain homeostasis. Occludin, one of tight junction protein, is crucial for BBB function. $H_2O_2$ induced occludin changes and effects in bovine brain BBB endothelial cells were examined in this study. The decrease of transendothelial electrical resistance (TEER) by $H_2O_2$ was due to disruption of occludin localization. Cytotoxicity test revealed that $H_2O_2$ did not cause cell death below 1 mM $H_2O_2$ within 4 hr. $H_2O_2$ caused intermittent disruption and loss of occludin at tight junctions and occludin disappeared with dose dependent manner from tight junction in confocal laser microscopy. But Western blot revealed that the total amounts of occludin increased by $H_2O_2$ administration. Transmission electron microscopy revealed that the ultrastructure of tight junction was not changed by $H_2O_2$. These data suggest that functional disruption of BBB by $H_2O_2$ was due to the localized loss of occludin in tight junction, but the expression of occludin increased in order to compensate the disrupted function in BBB.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.446-453
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• 2021

Background: Plastic particles less than 5 mm in diameter (microplastics) are well-known for causing various toxicities such as lung inflammation, oxidative stress, genotoxicity, and reproductive toxicity. As microplastics become smaller, they can move across cell membranes, the placenta, and the blood-brain barrier. Objectives: We evaluated the toxicities of polyethylene microplastics (PE-PMs) in dams and neonates through intragastric intubation of pregnant ICR mice. Methods: Low concentrations (0.01 mg/mouse/day) and high concentrations (0.1 mg/mouse/day) of polyethylene microplastics were administered from the ninth day of pregnancy to postnatal day seven. The control group was administered with distilled water. On the day of sacrifice, the weight of dams and neonates and the organ weight of neonates was measured. Further, acetylcholinesterase levels and glutathione peroxidase levels were evaluated by using a blood sample obtained on the sacrifice day. Results: No significant difference in the number of neonates was found, but the body weight gain of dams was seen to be lower in the low-dose group. On the other hand, we observed a consecutively declining trend in the weight gain and organ weight of neonates among the high-, control, and low-dose groups. Meanwhile, the serum acetylcholinesterase and glutathione peroxidase level were higher in the low-dose group compared to the control group. Further, the dose-dependent accumulation of microplastics in the organs of neonates revealed the transport of plastic particles from dams to their offspring. Conclusions: Although the exact mechanism of toxicity caused by microplastics could not be confirmed, it was validated that exposure to microplastics during pregnancy and lactation causes its migration between generations and accumulation throughout the body. Hence, it is necessary to evaluate the systemic toxicity of microplastics and assessment of co-morbidities such as second-generation toxicity, neurotoxicity, and depression following long-term exposure.