• Journal of Ginseng Research
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• v.44 no.1
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• pp.86-95
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• 2020

Background: Ginsenoside Rb1 (Rb1), one of the most abundant protopanaxadiol-type ginsenosides, exerts excellent neuroprotective effects even though it has low intracephalic exposure. Purpose: The present study aimed to elucidate the apparent contradiction between the pharmacokinetics and pharmacodynamics of Rb1 by studying the mechanisms underlying neuroprotective effects of Rb1 based on regulation of microflora. Methods: A pseudo germ-free (PGF) rat model was established, and neuroprotective effects of Rb1 were compared between conventional and PGF rats. The relative abundances of common probiotics were quantified to reveal the authentic probiotics that dominate in the neuroprotection of Rb1. The expressions of the gamma-aminobutyric acid (GABA) receptors, including GABAA receptors (α2, β2, and γ2) and GABAB receptors (1b and 2), in the normal, ischemia/reperfusion (I/R), and I/R+Rb1 rat hippocampus and striatum were assessed to reveal the neuroprotective mechanism of Rb1. Results: The results showed that microbiota plays a key role in neuroprotection of Rb1. The relative abundance of Lactobacillus helveticus (Lac.H) increased 15.26 fold after pretreatment with Rb1. I/R surgery induced effects on infarct size, neurological deficit score, and proinflammatory cytokines (IL-1β, IL-6, and TNF-α) were prevented by colonizing the rat gastrointestinal tract with Lac.H (1 × 10⁹ CFU) by gavage 15 d before I/R surgery. Both Rb1 and Lac.H upregulated expression of GABA receptors in I/R rats. Coadministration of a GABA_A receptor antagonist significantly attenuated neuroprotective effects of Rb1 and Lac.H. Conclusion: In sum, Rb1 exerts neuroprotective effects by regulating Lac.H and GABA receptors rather than through direct distribution to the target sites.

• Journal of Life Science
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• v.28 no.5
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• pp.597-604
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• 2018

Although the core mechanisms of Attention Deficit/Hyperactivity Disorder (ADHD) are unknown, several ADHD-associated proteins have been studied. G-protein - coupled receptor kinase interacting protein-1 (GIT1) is a multifunctional adapter protein that affects neuron growth and dendrite formation. GIT1-deficient mice have shown ADHD-like behavior and also recovered through amphetamine treatment. In this study, gliotransmitters were investigated in both intracellular and extracellular space from GIT1-deficient mice. To measure the amount of gliotransmitters, primary astrocyte cultures were taken from the cerebral and cerebellar cortices of wild (WT), hetero (HE), and knock-out (KO) mice. Major gliotransmitters were analyzed using high-performance liquid chromatography. It was observed that the amount of excitatory and inhibitory gliotransmitters were dependent on genotype and showed a change in excitation/inhibition ratios. Interestingly, the major excitatory gliotransmitter, glutamate, existed at the lowest level in WT mice, but the amount of inhibitory gliotransmitters, gamma-aminobutyric acid (GABA) and glycine, varied depending on brain region. Remarkably, an increased amount of GABA was measured at the intracellular cerebrum in WT mice compared with KO mice. It was presumed that KO mice would secrete more inhibitory gliotransmitters to compensate for GIT1 depletion or else acquire a defect to reuptake-secreted GABA. This may be a possible mechanism for ADHD pathology.

• Journal of Ginseng Research
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• v.46 no.6
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• pp.819-829
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• 2022

Background: Anxiolytic properties of Korean Red Ginseng (KRG) have been previously reported. However, the exact mechanism(s) of action remains to be elucidated. The present study investigated the effect of KRG on immobilization-induced anxiety-like behaviors in mice and explored the involvement of the serotonin and GABA systems and BDNF in the anxiolytic action. Methods: Mice were orally administered with KRG (200 mg/kg/day) for 4 weeks and immobilized once daily for 2 h. p-Chlorophenylalanine (p-CPA) was intraperitoneally injected on day 22-28, and flumazenil or bicuculline was injected on day 25-28. After behavioral evaluations, brains were dissected for biochemical analyses. Results: KRG improved immobilization-induced anxiety-like behaviors in mice, as assessed by the elevated plus maze (EPM) and marble burying tests (MBT). The anxiolytic effect of KRG was comparable to that of fluoxetine, a reference drug clinically used for anxiety disorders. A serotonin synthesis inhibitor, p-CPA, blocked the effect of KRG in the EPM and MBT, indicating the requirement of serotonin synthesis for anxiolytic action. In addition, the anxiolytic effect of KRG was inhibited by bicuculline (a GABA_A antagonist) in MBT, implying the involvement of GABA transmission. Western blotting analyses revealed that KRG upregulated the expression of tryptophan hydroxylase and GABA_A receptor in the brain, which was blocked by p-CPA. Enhanced BDNF expression by KRG in the hippocampus was also indicated to mediate the anxiolytic action of KRG in immobilized mice. Conclusion: KRG exhibited the anxiolytic effect in immobilized mice by multiple mechanisms of action, involving enhanced serotonin and GABA transmissions and BDNF expression.

• International Journal of Oral Biology
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• v.40 no.4
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• pp.183-187
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• 2015

The present study was aimed to evaluate the influence of glutaraldehyde (GA) concentration on multiple electron microscopic (EM) immunostaining using pre-embedding peroxidase and post-embedding immunogold method. Influence of various concentrations of GA included in the fixative on immuoreactivity was assessed in the multiple immunostaining using antisera against anti-transient receptor potential vanilloid 1 (TRPV1) for peroxidase staining and anti-GABA for immunogold labeling in the rat trigeminal caudal nucleus. Anti-TRPV1 antiserum had specificity in pre-embedding peroxidase staining when tissues were fixed with fixative containing paraformaldehyde (PFA) alone. Immunoreactivity for TRPV1 was specific in tissues fixed with fixative containing 0.5% GA at both perfusion and postfixation steps, though the immunoreactivity was weaker than in tissues fixed with fixative containing PFA alone. Tissues fixed with fixative containing 0.5% GA at the perfusion and postfixation steps showed specific immunogold staining for GABA. The results of the present study indicate that GA concentration is critical for immunoreactivity to antigens such as TRPV1 and GABA. This study also suggests that the appropriate GA concentration is 0.5% for multiple immunostaining with peroxidase labeling for TRPV1 and immunogold labeling for GABA.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.124.3-125
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• 2001

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.152-153
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• 2008

• The Korean Journal of Pain
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• v.37 no.3
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• pp.218-232
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• 2024

Background: Cynara scolymus has bioactive constituents and has been used for therapeutic actions. The present study was undertaken to investigate the mechanisms underlying pain-relieving effects of the hydroethanolic extract of C. scolymus (HECS). Methods: The antinociceptive activity of HECS was assessed through formalin and acetic acid-induced writhing tests at doses of 50, 100 and 200 mg/kg intraperitoneally. Additionally, naloxone (non-selective opioid receptors antagonist, 2 mg/kg), atropine (non-selective muscarinic receptors antagonist, 1 mg/kg), chlorpheniramine (histamine H₁-receptor antagonist, 20 mg/kg), cimetidine (histamine H₂-receptor antagonist, 12.5 mg/kg), flumazenil (GABA_A/BDZ receptor antagonist, 5 mg/kg) and cyproheptadine (serotonin receptor antagonist, 4 mg/kg) were used to determine the systems implicated in HECS-induced analgesia. Impact of HECS on locomotor activity was executed by open-field test. Determination of total phenolic content (TPC) and total flavonoid content (TFC) was done. Evaluation of antioxidant activity was conducted employing 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Results: HECS (50, 100 and 200 mg/kg) significantly indicated dose dependent antinociceptive activity against pain-related behavior induced by formalin and acetic acid (P < 0.001). Pretreatment with naloxone, atropine and flumazenil significantly reversed HECS-induced analgesia. Antinociceptive effect of HECS remained unaffected by chlorpheniramine, cimetidine and cyproheptadine. Locomotor activity was not affected by HECS. TPC and TFC of HECS were 59.49 ± 5.57 mgGAE/g dry extract and 93.39 ± 17.16 mgRE/g dry extract, respectively. DPPH free radical scavenging activity (IC₅₀) of HECS was 161.32 ± 0.03 ㎍/mL. Conclusions: HECS possesses antinociceptive activity which is mediated via opioidergic, cholinergic and GABAergic pathways.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.432-438
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• 2018

Worldwide, caffeine is among the most commonly used stimulatory substances. Unfortunately, significant caffeine consumption is associated with several adverse effects, ranging from sleep disturbances (including insomnia) to cardiovascular problems. This study investigates whether treatment with the Evodia rutaecarpa aqueous extract (ERAE) from berries and its major molecular component, evodiamine, can reduce the adverse caffeine-induced sleep-related and excitation effects. We combined measurements from the pentobarbital-induced sleep test, the open field test, and the locomotor activity test in mice that had been dosed with caffeine. We found that ERAE and evodiamine administration reduced the degree of caffeine-induced sleep disruption during the sleep test. Additionally, we found that evodiamine significantly inhibits caffeine-induced excitation during the open field test, as well as decreasing hyperlocomotion in the locomotor activity test. Additional in vitro experiments showed that caffeine administration decreased the expression of ${\gamma}$-aminobutyric acid $(GABA)_A$ receptor subunits in the mouse hypothalamus. However, evodiamine treatment significantly reversed this expression reduction. Taken together, our results demonstrate that ERAE and its major compound, evodiamine, provide an excellent candidate for the treatment or prevention of caffeine-induced sleep disturbances and excitatory states, and that the mechanism of these beneficial effects acts, at least in part, through the $GABA_A$-ergic system.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.55-66
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• 2005

Cnidii Rhizoma (CR) was subjected to extraction with 70% methanol and tested to determine whether it has anxiolytic activity in mouse by employing staircase and rotarod tests. In addition, to understand the mechanism of anxiolytic action, CR, picrotoxin, yohimbine, isoniazid and strychnine were utilized to deliniate the potential involvement of GABA and glycine receptors in the action of Cnidii Rhizoma. To gain insights into the safety of Cnidii Rhizoma extract, behavioral and MTT tests were carried out. The results were obtained as follows: 1. CR extract had little effect on climbing numbers in the stair case test. 2. CR extract had considerable anti-anxiety effects as evidenced by the reduction of rearing numbers in the stair case test. 3. CR extract had little effect on muscle relaxation. 4. Anxiolytic actions of CR extract appeared to be mediated by glycine receptor activation. 5. Cytotoxicity in the neuronal cell was not observed and no strange behaviors were found. In short, these results indicate that CR extract has the ability to exert anxiolytic activity, possibly by activating glycine receptor with little side effects in mouse.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.586-592
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• 2017

Sinomenium acutum has been long used in the preparations of traditional medicine in Japan, China and Korea for the treatment of various disorders including rheumatism, fever, pulmonary diseases and mood disorders. Recently, it was reported that Sinomenium acutum, has sedative and anxiolytic effects mediated by GABA-ergic systems. These experiments were performed to investigate whether sinomenine (SIN), an alkaloid derived from Sinomenium acutum enhances pentobarbital-induced sleep via ${\gamma}$-aminobutyric acid (GABA)-ergic systems, and modulates sleep architecture in mice. Oral administration of SIN (40 mg/kg) markedly reduced spontaneous locomotor activity, similar to diazepam (a benzodiazepine agonist) in mice. SIN shortened sleep latency, and increased total sleep time in a dose-dependent manner when co-administrated with pentobarbital (42 mg/kg, i.p.). SIN also increased the number of sleeping mice and total sleep time by concomitant administration with the sub-hypnotic dosage of pentobarbital (28 mg/kg, i.p.). SIN reduced the number of sleep-wake cycles, and increased total sleep time and non-rapid eye movement (NREM) sleep. In addition, SIN also increased chloride influx in the primary cultured hypothalamic neuronal cells. Furthermore, protein overexpression of glutamic acid decarboxylase ($GAD_{65/67}$) and $GABA_A$ receptor subunits by western blot were found, being activated by SIN. In conclusion, SIN augments pentobarbital-induced sleeping behaviors through $GABA_A$-ergic systems, and increased NREM sleep. It could be a candidate for the treatment of insomnia.