1.Cognitive improvement effect of gintonin might be associated with blood-brain barrier permeability enhancement: dynamic contrastenhanced MRI pilot study
Woo-Jin LEE ; Yong-Won SHIN ; Hyeyeon CHANG ; Hye-Rim SHIN ; Won-Woo KIM ; Seok-Won JUNG ; Seung-Hong CHOI ; Manho KIM ; Seung-Yeol NAH
Translational and Clinical Pharmacology 2021;29(1):21-32
Along with the multiple neuroprotective effect, recent studies suggest that gintonin might increase the blood brain barrier permeability. We evaluated the effect of gintonin on the vascular permeability changes in different brain segments, using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). In this 8-week, randomized, open label pilot study, ten participants with subjective memory impairment but preserved cognitive function assigned to gintonin-enriched fraction (GEF) 300 mg/day or placebo groups. Korean versions of the Alzheimer's disease assessment scale (ADAS-K) and DCE-MRI parameters including Ktrans and Vp in different brain segments were evaluated at baseline and at 8 weeks after treatment. Nine participants completed the study protocol. No adverse events occurred during the observation period for 8 weeks in both groups. Following gintonin administration, increment trends of the brain permeability that did not reach a statistical significance were observed in the left hippocampus (Ktrans and Vp , both, p = 0.062), left thalamus and in left putamen (Ktrans , p = 0.062), and left insula and right amygdala (Vp , p = 0.062), but not in the control placebo group. The increment of the Ktrans value in the left thalamus from the baseline was highly correlated with the change of the ADAS scores (r = −0.900, p = 0.037). Gintonin might enhance the blood-brain barrier (BBB) permeability in the brain structures involved in cognitive functions. Further efficacy exploration for the synergistic effect of gintonin's BBB permeability enhancement to its other cognitive enhancing mechanisms are warranted.
2.Impact of Hospital Volume of Percutaneous Coronary Intervention (PCI) on In-Hospital Outcomes in Patients with Acute Myocardial Infarction: Based on the 2014 Cohort of the Korean Percutaneous Coronary Intervention (K-PCI) Registry
Byong-Kyu KIM ; Deuk-Young NAH ; Kang Un CHOI ; Jun-Ho BAE ; Moo-Yong RHEE ; Jae-Sik JANG ; Keon-Woong MOON ; Jun-Hee LEE ; Hee-Yeol KIM ; Seung-Ho KANG ; Woo hyuk SONG ; Seung Uk LEE ; Byung-Ju SHIM ; Hang jae CHUNG ; Min Su HYON
Korean Circulation Journal 2020;50(11):1026-1036
Background and Objectives:
The relationship between the hospital percutaneous coronary intervention (PCI) volumes and the in-hospital clinical outcomes of patients with acute myocardial infarction (AMI) remains the subject of debate. This study aimed to determine whether the in-hospital clinical outcomes of patients with AMI in Korea are significantly associated with hospital PCI volumes.
Methods:
We selected and analyzed 17,121 cases of AMI, that is, 8,839 cases of non-ST-segment elevation myocardial infarction and 8,282 cases of ST-segment elevation myocardial infarction, enrolled in the 2014 Korean percutaneous coronary intervention (K-PCI) registry. Patients were divided into 2 groups according to hospital annual PCI volume, that is, to a high-volume group (≥400/year) or a low-volume group (<400/year). Major adverse cardiovascular and cerebrovascular events (MACCEs) were defined as composites of death, cardiac death, non-fatal myocardial infarction (MI), stent thrombosis, stroke, and need for urgent PCI during index admission after PCI.
Results:
Rates of MACCE and non-fatal MI were higher in the low-volume group than in the high-volume group (MACCE: 10.9% vs. 8.6%, p=0.001; non-fatal MI: 4.8% vs. 2.6%, p=0.001, respectively). Multivariate regression analysis showed PCI volume did not independently predict MACCE.
Conclusions
Hospital PCI volume was not found to be an independent predictor of in-hospital clinical outcomes in patients with AMI included in the 2014 K-PCI registry.
3.Gintonin, an exogenous ginseng-derived LPA receptor ligand, promotes corneal wound healing.
Hyeon Joong KIM ; Joon Young KIM ; Byung Hwan LEE ; Sun Hye CHOI ; Hyewon RHIM ; Hyoung Chun KIM ; Seoung Yob AHN ; Soon Wuk JEONG ; Minhee JANG ; Ik Hyun CHO ; Seung Yeol NAH
Journal of Veterinary Science 2017;18(3):387-397
Ginseng gintonin is an exogenous ligand of lysophosphatidic acid (LPA) receptors. Accumulating evidence shows LPA helps in rapid recovery of corneal damage. The aim of this study was to evaluate the therapeutic efficacy of gintonin in a rabbit model of corneal damage. We investigated the signal transduction pathway of gintonin in human corneal epithelium (HCE) cells to elucidate the underlying molecular mechanism. We next evaluated the therapeutic effects of gintonin, using a rabbit model of corneal damage, by undertaking histochemical analysis. Treatment of gintonin to HCE cells induced transient increases of [Ca²⁺](i) in concentration-dependent and reversible manners. Gintonin-mediated mobilization of [Ca²⁺](i) was attenuated by LPA1/3 receptor antagonist Ki16425, phospholipase C inhibitor U73122, inositol 1,4,5-triphosphate receptor antagonist 2-APB, and intracellular Ca²⁺ chelator BAPTA-AM. Gintonin facilitated in vitro wound healing in a concentration-dependent manner. When applied as an eye-drop to rabbits with corneal damage, gintonin rapidly promoted recovery. Histochemical analysis showed gintonin decreased corneal apoptosis and increased corneal cell proliferation. We demonstrated that LPA receptor activation by gintonin is linked to in vitro and in vivo therapeutic effects against corneal damage. Gintonin can be applied as a clinical agent for the rapid healing of corneal damage.
Apoptosis
;
Cell Proliferation
;
Corneal Injuries
;
Epithelium, Corneal
;
Humans
;
In Vitro Techniques
;
Inositol 1,4,5-Trisphosphate
;
Mortuary Practice
;
Panax
;
Rabbits
;
Receptors, Lysophosphatidic Acid
;
Signal Transduction
;
Therapeutic Uses
;
Type C Phospholipases
;
Wound Healing*
;
Wounds and Injuries*
4.Differential Effects of Quercetin and Quercetin Glycosides on Human α7 Nicotinic Acetylcholine Receptor-Mediated Ion Currents.
Byung Hwan LEE ; Sun Hye CHOI ; Hyeon Joong KIM ; Seok Won JUNG ; Sung Hee HWANG ; Mi Kyung PYO ; Hyewhon RHIM ; Hyoung Chun KIM ; Ho Kyoung KIM ; Sang Mok LEE ; Seung Yeol NAH
Biomolecules & Therapeutics 2016;24(4):410-417
Quercetin is a flavonoid usually found in fruits and vegetables. Aside from its antioxidative effects, quercetin, like other flavonoids, has a various neuropharmacological actions. Quercetin-3-O-rhamnoside (Rham1), quercetin-3-O-rutinoside (Rutin), and quercetin-3-(2(G)-rhamnosylrutinoside (Rham2) are mono-, di-, and tri-glycosylated forms of quercetin, respectively. In a previous study, we showed that quercetin can enhance α7 nicotinic acetylcholine receptor (α7 nAChR)-mediated ion currents. However, the role of the carbohydrates attached to quercetin in the regulation of α7 nAChR channel activity has not been determined. In the present study, we investigated the effects of quercetin glycosides on the acetylcholine induced peak inward current (I(ACh)) in Xenopus oocytes expressing the α7 nAChR. I(ACh) was measured with a two-electrode voltage clamp technique. In oocytes injected with α7 nAChR copy RNA, quercetin enhanced I(ACh), whereas quercetin glycosides inhibited I(ACh). Quercetin glycosides mediated an inhibition of I(ACh), which increased when they were pre-applied and the inhibitory effects were concentration dependent. The order of I(ACh) inhibition by quercetin glycosides was Rutin≥Rham1>Rham2. Quercetin glycosides-mediated I(ACh) enhancement was not affected by ACh concentration and appeared voltage-independent. Furthermore, quercetin-mediated I(ACh) inhibition can be attenuated when quercetin is co-applied with Rham1 and Rutin, indicating that quercetin glycosides could interfere with quercetin-mediated α7 nAChR regulation and that the number of carbohydrates in the quercetin glycoside plays a key role in the interruption of quercetin action. These results show that quercetin and quercetin glycosides regulate the α7 nAChR in a differential manner.
Acetylcholine*
;
Carbohydrates
;
Flavonoids
;
Fruit
;
Glycosides*
;
Humans*
;
Oocytes
;
Quercetin*
;
Receptors, Nicotinic
;
RNA
;
Rutin
;
Vegetables
;
Xenopus
5.Resveratrol Inhibits GABAC rho Receptor-Mediated Ion Currents Expressed in Xenopus Oocytes.
Byung Hwan LEE ; Sun Hye CHOI ; Sung Hee HWANG ; Hyeon Joong KIM ; Joon Hee LEE ; Seung Yeol NAH
The Korean Journal of Physiology and Pharmacology 2013;17(2):175-180
Resveratrol is a phytoalexin found in grapes, red wine, and berries. Resveratrol has been known to have many beneficial health effects, such as anti-cancer, neuroprotective, anti-inflammatory, and life-prolonging effects. However, relatively little is known about the effects of resveratrol on the regulation of ligand-gated ion channels. We have previously reported that resveratrol regulates subsets of homomeric ligand-gated ion channels such as those of 5-HT3A receptors. The gamma-aminobutyric acidC (GABAC) receptor is mainly expressed in retinal bipolar cells and plays an important role in visual processing. In the present study, we examined the effects of resveratrol on the channel activity of homomeric GABAC receptor expressed in Xenopus oocytes injected with cRNA encoding human GABAC rho subunits. Our data show that the application of GABA elicits an inward peak current (IGABA) in oocytes that express the GABAC receptor. Resveratrol treatment had no effect on oocytes injected with H2O or with GABAC receptor cRNA. Co-treatment with resveratrol and GABA inhibited IGABA in oocytes with GABAC receptors. The inhibition of IGABA by resveratrol was in a reversible and concentration-dependent manner. The IC50 of resveratrol was 28.9+/-2.8 microM in oocytes expressing GABAC receptor. The inhibition of IGABA by resveratrol was in voltage-independent and non-competitive manner. These results indicate that resveratrol might regulate GABAC receptor expression and that this regulation might be one of the pharmacological actions of resveratrol on the nervous system.
Fruit
;
gamma-Aminobutyric Acid
;
Humans
;
Inhibitory Concentration 50
;
Ligand-Gated Ion Channels
;
Nervous System
;
Oocytes
;
Receptors, GABA
;
Retinal Bipolar Cells
;
RNA, Complementary
;
Sesquiterpenes
;
Stilbenes
;
Vitis
;
Wine
;
Xenopus
6.Inhibitory Effects of Ginsenoside Metabolites, Compound K and Protopanaxatriol, on GABAC Receptor-Mediated Ion Currents.
Byung Hwan LEE ; Sung Hee HWANG ; Sun Hye CHOI ; Hyeon Joong KIM ; Joon Hee LEE ; Sang Mok LEE ; Yun Gyong AHN ; Seung Yeol NAH
The Korean Journal of Physiology and Pharmacology 2013;17(2):127-132
Ginsenosides, one of the active ingredients of Panax ginseng, show various pharmacological and physiological effects, and they are converted into compound K (CK) or protopanaxatriol (M4) by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. The gamma-aminobutyric acid receptorC (GABAC) is primarily expressed in retinal bipolar cells and several regions of the brain. However, little is known of the effects of ginsenoside metabolites on GABAC receptor channel activity. In the present study, we examined the effects of CK and M4 on the activity of human recombinant GABAC receptor (rho1) channels expressed in Xenopus oocytes by using a 2-electrode voltage clamp technique. In oocytes expressing GABAC receptor cRNA, we found that CK or M4 alone had no effect in oocytes. However, co-application of either CK or M4 with GABA inhibited the GABA-induced inward peak current (IGABA). Interestingly, pre-application of M4 inhibited IGABA more potently than CK in a dose-dependent and reversible manner. The half-inhibitory concentration (IC50) values of CK and M4 were 52.1+/-2.3 and 45.7+/-3.9 microM, respectively. Inhibition of IGABA by CK and M4 was voltage-independent and non-competitive. This study implies that ginsenoside metabolites may regulate GABAC receptor channel activity in the brain, including in the eyes.
Brain
;
Eye
;
gamma-Aminobutyric Acid
;
Ginsenosides
;
Humans
;
Oocytes
;
Panax
;
Retinal Bipolar Cells
;
RNA, Complementary
;
Sapogenins
;
Xenopus
7.Activation of Lysophosphatidic Acid Receptor Is Coupled to Enhancement of Ca(2+)-Activated Potassium Channel Currents.
Sun Hye CHOI ; Byung Hwan LEE ; Hyeon Joong KIM ; Sung Hee HWANG ; Sang Mok LEE ; Seung Yeol NAH
The Korean Journal of Physiology and Pharmacology 2013;17(3):223-228
The calcium-activated K+ (BKCa) channel is one of the potassium-selective ion channels that are present in the nervous and vascular systems. Ca2+ is the main regulator of BKCa channel activation. The BKCa channel contains two high affinity Ca2+ binding sites, namely, regulators of K+ conductance, RCK1 and the Ca2+ bowl. Lysophosphatidic acid (LPA, 1-radyl-2-hydroxy-sn-glycero-3-phosphate) is one of the neurolipids. LPA affects diverse cellular functions on many cell types through G protein-coupled LPA receptor subtypes. The activation of LPA receptors induces transient elevation of intracellular Ca2+ levels through diverse G proteins such as Galphaq/11, Galphai, Galpha12/13, and Galphas and the related signal transduction pathway. In the present study, we examined LPA effects on BKCa channel activity expressed in Xenopus oocytes, which are known to endogenously express the LPA receptor. Treatment with LPA induced a large outward current in a reversible and concentration-dependent manner. However, repeated treatment with LPA induced a rapid desensitization, and the LPA receptor antagonist Ki16425 blocked LPA action. LPA-mediated BKCa channel activation was also attenuated by the PLC inhibitor U-73122, IP3 inhibitor 2-APB, Ca2+ chelator BAPTA, or PKC inhibitor calphostin. In addition, mutations in RCK1 and RCK2 also attenuated LPA-mediated BKCa channel activation. The present study indicates that LPA-mediated activation of the BKCa channel is achieved through the PLC, IP3, Ca2+, and PKC pathway and that LPA-mediated activation of the BKCa channel could be one of the biological effects of LPA in the nervous and vascular systems.
Binding Sites
;
Egtazic Acid
;
Estrenes
;
GTP-Binding Proteins
;
Ion Channels
;
Isoxazoles
;
Lysophospholipids
;
Naphthalenes
;
Oocytes
;
Potassium
;
Potassium Channels
;
Propionates
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Pyrrolidinones
;
Receptors, Lysophosphatidic Acid
;
Signal Transduction
;
Xenopus
8.Effects of Protopanaxatriol-Ginsenoside Metabolites on Rat N-Methyl-D-Aspartic Acid Receptor-Mediated Ion Currents.
Tae Joon SHIN ; Sung Hee HWANG ; Sun Hye CHOI ; Byung Hwan LEE ; Jiyeon KANG ; Hyeon Joong KIM ; R Suzanne ZUKIN ; Hyewhon RHIM ; Seung Yeol NAH
The Korean Journal of Physiology and Pharmacology 2012;16(2):113-118
Ginsenosides are low molecular weight glycosides found in ginseng that exhibit neuroprotective effects through inhibition of N-methyl-D-aspartic acid (NMDA) receptor channel activity. Ginsenosides, like other natural compounds, are metabolized by gastric juices and intestinal microorganisms to produce ginsenoside metabolites. However, little is known about how ginsenoside metabolites regulate NMDA receptor channel activity. In the present study, we investigated the effects of ginsenoside metabolites, such as compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT), on oocytes that heterologously express the rat NMDA receptor. NMDA receptor-mediated ion current (INMDA) was measured using the 2-electrode voltage clamp technique. In oocytes injected with cRNAs encoding NMDA receptor subunits, PPT, but not CK or PPD, reversibly inhibited INMDA in a concentration-dependent manner. The IC50 for PPT on INMDA was 48.1+/-4.6 microM, was non-competitive with NMDA, and was independent of the membrane holding potential. These results demonstrate the possibility that PPT interacts with the NMDA receptor, although not at the NMDA binding site, and that the inhibitory effects of PPT on INMDA could be related to ginseng-mediated neuroprotection.
Animals
;
Binding Sites
;
Gastric Juice
;
Ginsenosides
;
Glycosides
;
Inhibitory Concentration 50
;
Membranes
;
Molecular Weight
;
N-Methylaspartate
;
Neuroprotective Agents
;
Oocytes
;
Panax
;
Rats
;
RNA, Complementary
;
Sapogenins
;
Tuberculin
9.Quercetin Inhibits alpha3beta4 Nicotinic Acetylcholine Receptor-Mediated Ion Currents Expressed in Xenopus Oocytes.
Byung Hwan LEE ; Sung Hee HWANG ; Sun Hye CHOI ; Tae Joon SHIN ; Jiyeon KANG ; Sang Mok LEE ; Seung Yeol NAH
The Korean Journal of Physiology and Pharmacology 2011;15(1):17-22
Quercetin mainly exists in the skin of colored fruits and vegetables as one of flavonoids. Recent studies show that quercetin, like other flavonoids, has diverse pharmacological actions. However, relatively little is known about quercetin effects in the regulations of ligand-gated ion channels. In the previous reports, we have shown that quercetin regulates subsets of homomeric ligand-gated ion channels such as glycine, 5-HT3A and alpha7 nicotinic acetylcholine receptors. In the present study, we examined quercetin effects on heteromeric neuronal alpha3beta4 nicotinic acetylcholine receptor channel activity expressed in Xenopus oocytes after injection of cRNA encoding bovine neuronal alpha3 and beta4 subunits. Treatment with acetylcholine elicited an inward peak current (IACh) in oocytes expressing alpha3beta4 nicotinic acetylcholine receptor. Co-treatment with quercetin and acetylcholine inhibited IACh in oocytes expressing alpha3beta4 nicotinic acetylcholine receptors. The inhibition of IACh by quercetin was reversible and concentration-dependent. The half-inhibitory concentration (IC50) of quercetin was 14.9+/-0.8 microM in oocytes expressing alpha3beta4 nicotinic acetylcholine receptor. The inhibition of IACh by quercetin was voltage-independent and non-competitive. These results indicate that quercetin might regulate alpha3beta4 nicotinic acetylcholine receptor and this regulation might be one of the pharmacological actions of quercetin in nervous systems.
Acetylcholine
;
Flavonoids
;
Fruit
;
Glycine
;
Ligand-Gated Ion Channels
;
Nervous System
;
Neurons
;
Oocytes
;
Quercetin
;
Receptors, Nicotinic
;
RNA, Complementary
;
Skin
;
Social Control, Formal
;
Vegetables
;
Xenopus
10.Inhibitory Effects of Quercetin on Muscle-type of Nicotinic Acetylcholine Receptor-Mediated Ion Currents Expressed in Xenopus Oocytes.
Byung Hwan LEE ; Tae Joon SHIN ; Sung Hee HWANG ; Sun Hye CHOI ; Jiyeon KANG ; Hyeon Joong KIM ; Chan Woo PARK ; Soo Han LEE ; Seung Yeol NAH
The Korean Journal of Physiology and Pharmacology 2011;15(4):195-201
The flavonoid quercetin is a low molecular weight compound generally found in apple, gingko, tomato, onion and other red-colored fruits and vegetables. Like other flavonoids, quercetin has diverse pharmacological actions. However, relatively little is known about the influence of quercetin effects in the regulation of ligand-gated ion channels. Previously, we reported that quercetin regulates subsets of nicotinic acetylcholine receptors such as alpha3beta4, alpha7 and alpha9alpha10. Presently, we investigated the effects of quercetin on muscle-type of nicotinic acetylcholine receptor channel activity expressed in Xenopus oocytes after injection of cRNA encoding human fetal or adult muscle-type of nicotinic acetylcholine receptor subunits. Acetylcholine treatment elicited an inward peak current (IACh) in oocytes expressing both muscle-type of nicotinic acetylcholine receptors and co-treatment of quercetin with acetylcholine inhibited IACh. Pre-treatment of quercetin further inhibited IACh in oocytes expressing adult and fetal muscle-type nicotinic acetylcholine receptors. The inhibition of IACh by quercetin was reversible and concentration-dependent. The IC50 of quercetin was 18.9+/-1.2 microM in oocytes expressing adult muscle-type nicotinic acetylcholine receptor. The inhibition of IACh by quercetin was voltage-independent and non-competitive. These results indicate that quercetin might regulate human muscle-type nicotinic acetylcholine receptor channel activity and that quercetin-mediated regulation of muscle-type nicotinic acetylcholine receptor might be coupled to regulation of neuromuscular junction activity.
Acetylcholine
;
Adult
;
Flavonoids
;
Fruit
;
Ginkgo biloba
;
Humans
;
Inhibitory Concentration 50
;
Ligand-Gated Ion Channels
;
Lycopersicon esculentum
;
Molecular Weight
;
Neuromuscular Junction
;
Onions
;
Oocytes
;
Quercetin
;
Receptors, Nicotinic
;
RNA, Complementary
;
Vegetables
;
Xenopus

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