• International Journal of Oral Biology
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• v.33 no.4
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• pp.217-221
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• 2008

Bicuculline is one of the most commonly used $GABA_A$ receptor antagonists in electrophysiological research. Because of its poor water solubility, bicuculline quaternary ammonium salts such as bicuculline methiodide (BMI) and bicuculline methbromide are preferred. However, a number of studies have shown that BMI has non-$GABA_A$ receptor-mediated effects. The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is implicated in the processing of nociceptive signaling. In this study, we investigated whether BMI has non-GABA receptor-mediated activity in Vc SG neurons using a whole cell patch clamp technique. SG neurons were depolarized by application of BMI ($20{\mu}M$) using a high $Cl^-$ pipette solution. GABA ($30-100{\mu}M$) also induced membrane depolarization of SG neuron. Although BMI is known to be a $GABA_A$ receptor antagonist, GABA-induced membrane depolarization was enhanced by co-application with BMI. However, free base bicuculline (fBIC) and picrotoxin (PTX), a $GABA_A$ and $GABA_C$ receptor antagonist, blocked the GABA-induced response. Furthermore, BMI-induced membrane depolarization persisted in the presence of PTX or an antagonist cocktail consisting of tetrodotoxin ($Na^+$ channel blocker), AP-5 (NMDA receptor antagonist), CNQX (non-NMDA receptor antagonist), and strychnine (glycine receptor antagonist). Thus BMI induces membrane depolarization by directly acting on postsynaptic Vc SG neurons in a manner which is independent of $GABA_A$ receptors. These results suggest that other unknown mechanisms may be involved in BMI-induced membrane depolarization.

• KSBB Journal
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• v.15 no.6
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• pp.615-620
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• 2000

To obtain quality germinated brown rices containing high levels of ${\gamma}$-aminobutyric acid (GABA), chitosan was applied during the brown rice germination. The GABA contents in germinated brown rices (1,035 nmole/g fresh weight) and brown rices germinated by water (771 nmole/g fresh weight) or by lactiv acid (728 nmole/g fresh weight). In addition to the enhancement of GABA, germination in the chitosan solution increased alanine concentration and decreased glutamic acid, aspartic acid and serine concentrations in the brown rices. The activity of glutamate decarboxylase was also enhanced by the chitosan treatment. Furthermore, germination by chitosan reduced fungal contamination markdely, compared with germination by water or germination by lactic acid. These results suggest that quality germinated brown rices containing high levels of GABA can be obtained by chitosan application.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.65-68
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• 2000

To obtain quality germinated brown rices containing high levels of ${\gamma}-amonobutyric\;acid$(GABA), chitosan was appliec during the germination of brown rices. The GABA contents of germinated brown rices (1,035 umole/g fresh weight) with 100 ppm chitosan solution for 72 hr were higher than those of ungerminated brown rices (136 nmole/g fresh weight) and brown rices germinated with water (771 nmole/g fresh weight) or with lactic acid (728 nmole/g fresh weight). In addition to the enhancement of GABA, germination in the chitosan solution increased alanine and decreased glutamic acid, aspartic acid and serine in the brown rices. The activity of glutamate decarboxylase was also enhanced by the treatment of chitosan. Furthermore, the germination with chitosan reduced fungi contamination markedly compared with water germination or lactic acid germination. These results suggest that quality germinated brown rices containing high levels of GABA can be obtained by chitosan application.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.106-110
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• 2007

Background: A phosphodiesterase 5 inhibitor, sildenafil, has been effective against nociception. Several lines of evidence have demonstrated the role of the GABAergic pathway in the modulation of nociception. The impact of the GABA receptors on sildenafil was studied using the formalin test at the spinal level. Methods: Male SD rats were prepared for intrathecal catheterization. The formalin test was induced by subcutaneous injection of formalin solution. The change in the activity of sildenafil was examined after pre-treatment with GABA receptor antagonists ($GABA_A$ receptor antagonist, bicuculline; $GABA_B$ receptor antagonist, saclofen). Results: Intrathecal sildenafil dose-dependently attenuated the flinching observed during phase 1 and 2 in the formalin test. The antinociceptive effect of sildenafil was reversed by the $GABA_B$ receptor antagonist (saclofen) but not by the $GABA_A$ receptor antagonist (bicuculline) in both phases. Conclusions: Intrathecal sildenafil suppressed acute pain and the facilitated pain state. The antinociception of sildenafil is mediated via the $GABA_B$ receptor, but not the $GABA_A$ receptor, at the spinal level.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.440-446
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• 2021

GABA (γ-aminobutyric acid) has various beneficial effects on human health such as anti-hypertension, diuretic, tranquilizer, sleep induction and anti-stress functions. In this study, the properties and the antioxidizing effects of a fermented solution was investigated by applying GABA producing lactic acid bacteria (LAB) from kimchi to corn silk extract. Lactobacillus plantarum LAB459 was identified by physiological properties, carbohydrate fermentation pattern and 16s rRNA sequence analysis. Also, the GABA production ability of the separated L. plantarum LAB459 was confirmed through TLC and HPLC analysis. Moreover, from the fermentation of corn silk extract with skim milk, it was revealed that approximately 1 ㎍/mg of GABA produced by lyophilized ferments was yielded. Lastly, the flavonoid content and DPPH radical scavenging activity were found to be high in the lyophilized ferments than in the aqueous extracts. Therefore, L. plantarum LAB459 is considered to be used as a starter culture for various fermented foods or in food and medicinal materials.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.104-109
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• 2007

Lactic acid bacteria that accumulated ${\gamma}-aminobutyric$ acid (GABA) in culture medium were screened to identify strains with high GAB A-producing ability. One strain, MS, which was isolated from kimchi, showed the highest GABA-producing ability among the screened strains. MS was identified as Lactobacillus buchneri based on Gram-staining, metabolic characteristics, and 16S rDNA sequence determination, Optimum culture conditions for GABA production were determined: MRS broth containing 5% MSG, 1% NaCl, and 1% glucose, at an initial pH of 5.0, the incubation temperature at $30^{\circ}C$ for 36 h. Under these conditions, MS produced GABA at a concentration of 251 mM with a 94% GABA conversion rate. Moreover, culture extracts of Lb. buchneri MS partially or completely protected neuronal cells against neurotoxicantinduced cell death.

• KSBB Journal
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• v.27 no.2
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• pp.127-130
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• 2012

In this study, the effects of pH, temperature, IPTG concentration and substrate (MSG) concentration on gamma-aminobutyric acid (GABA) production in engineered Escherichia coli were investigated. Glutamate decarboxylase and glutamate/GABA antiporter were overexpressed in GABA aminotransferase knock-out strain for GABA production. The result of optimization study showed the GABA bioconversion was optimized at pH 3.5, $30^{\circ}C$, 0.5 mM IPTG, 10 g/L MSG. At this condition, 5.23 g/L of final GABA concentration of was achieved from 10 g/L of MSG, which corresponded to a GABA yield of 85.77%.

• Natural Product Sciences
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• v.13 no.4
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• pp.384-389
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• 2007

Treatment of mice with Korean Red Ginseng (KRG) changed glutamic acid and GABA content in the mouse brain tissue with pentylenetetrazole (PTZ)-induced convulsion. KRG were orally administered at a dose of 50, 100 mg/kg for two weeks. The electroconvulsions (MES) and PTZ-induced convulsion were reduced but those induced by strychnine, bicuculine and picrotoxin were not. PTZ-induced convulsion decreased the $\~{a}$-aminobutyric acid (GABA) content in brain compared to control group while the content was increased in KRG-treated group compared to PTZ group. In the PTZ-treated group, the GABA-transaminase (GABA-T) activity was increased by 59.6%, while no effect was observed on glutamate decarboxylase (GAD) activity. These results support that the KRG decreased the GABA contents and modulated the glutamic acid contents in the brain.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.26-31
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• 2012

For the purpose of production of GABA-rich tomato paste, this study was carried out to investigate GABA producing lactic acid bacteria from Korean traditional fermented food, Kimchi and optimize the culture conditions. As a result of fermentation, Lactobacillus brevis B3-20 among lactic acid bacteria isolated at the pre-experiments was the best producer of GABA at the tomato paste medium with 50%(wet-base) levels of dionized water. At the result of fermentation on the tomato paste medium with 0.5%(w/w) yeast extract, as a source of nitrogen, 3%(w/w) MSG(monosodium glutamate) and dionized water(the ratio of tomato paste and water was 2:8), Lb. brevis B3-20 produced the maximum GABA concentration, 143.38 mM. GABA-rich tomato paste showed the activity of free radical scavenging. Because GABA-rich tomato paste have functional ingredients such as ascorbic acid, lycopene, carotenoid, as well as GABA by lactic acid bacteria fermentation, GABA-rich tomato paste can be considered high functional materials.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.114-118
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• 1997

Nicotinamide and GABA(${\gamma}$-aminobutyric acid) contents in sericultural products, Mori Folium, Mori Fructus, Mori Cortex Radicis, silkworm podwer, Bombycis Exerementum and Bombycis Corpus were analyzed by HPLC. Nicotinamide content was higher in silkworm derived-products than in mulberry derived-products. Nicotinamide contained Bombycis Excrementum was the highest by 0.31 mg/g DW among the sericultural products. GABA content showed the highest by 1.68 mg/g DW in Mori Cortex Radicis among the sericultural products.