• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.450-459
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• 2017

This study evaluated the effects of culture conditions, including carbon and nitrogen sources, L-monosodium glutamate (MSG), and initial pH, on gamma-aminobutyric acid (GABA) production by Lactobacillus brevis HYE1 isolated from kimchi, a Korean traditional fermented food. L. brevis HYE1 was screened by the production analysis of GABA and genetic analysis of the glutamate decarboxylase gene, resulting in 14.64 mM GABA after 48 h of cultivation in MRS medium containing 1% (w/v) MSG. In order to increase GABA production by L. brevis HYE1, the effects of carbon and nitrogen sources on GABA production were preliminarily investigated via one-factor-at-a-time optimization strategy. As the results, 2% maltose and 3% tryptone were determined to produce 17.93 mM GABA in modified MRS medium with 1% (w/v) MSG. In addition, the optimal MSG concentration and initial pH were determined to be 1% and 5.0, respectively, resulting in production of 18.97 mM GABA. Thereafter, response surface methodology (RSM) was applied to determine the optimal conditions of the above four factors. The results indicate that pH was the most significant factor for GABA production. The optimal culture conditions for maximum GABA production were also determined to be 2.14% (w/v) maltose, 4.01% (w/v) tryptone, 2.38% (w/v) MSG, and an initial pH of 4.74. In these conditions, GABA production by L. brevis HYE1 was predicted to be 21.44 mM using the RSM model. The experiment was performed under these optimized conditions, resulting in GABA production of 18.76 mM. These results show that the predicted and experimental values of GABA production are in good agreement.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.1
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• pp.27-38
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• 2021

Excessive salt intake induces hypertension, but several gamma-aminobutyric acid (GABA) supplements have been shown to reduce blood pressure. GABA-salt, a fermented salt by L. brevis BJ20 containing GABA was prepared through the post-fermentation with refined salt and the fermented GABA extract. We evaluated the effect of GABA-salt on hypertension in a high salt, high cholesterol diet induced mouse model. We analyzed type 1 macrophage (M1) polarization, the expression of M1 related cytokines, GABA receptor expression, endothelial cell (EC) dysfunction, vascular smooth muscle cell (VSMC) proliferation, and medial thicknesses in mice model. GABA-salt attenuated diet-induced blood pressure increases, M1 polarization, and TNF-α and inducible nitric oxide synthase (NOS) levels in mouse aortas, and in salt treated macrophages in vitro. Furthermore, GABA-salt induced higher GABAB receptor and endothelial NOS (eNOS) and eNOS phosphorylation levels than those observed in salt treated ECs. In addition, GABA-salt attenuated EC dysfunction by decreasing the levels of adhesion molecules (E-selectin, Intercellular Adhesion Molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1]) and of von Willebrand Factor and reduced EC death. GABA-salt also reduced diet-induced reductions in the levels of eNOS, phosphorylated eNOS, VSMC proliferation and medial thickening in mouse aortic tissues, and attenuated Endothelin-1 levels in salt treated VSMCs. In summary, GABA-salt reduced high salt, high cholesterol diet induced hypertension in our mouse model by reducing M1 polarization, EC dysfunction, and VSMC proliferation.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.408-415
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• 2018

This study aimed to investigate the changes in the ${\gamma}$-aminobutyric acid (GABA) content of bitter melon (Momordica charantia L.) cultivated from different regions, with different harvest times and at various maturation stages. Methods for observing the changes in GABA content were validated by determining the specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), and precision and accuracy using the HPLC-FLD system. Results showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9999. The LOD and LOQ values for GABA were 0.29 and $0.87{\mu}g/mL$, respectively. The relative standard deviations for intra- and inter-day precision of GABA were less than 5%. The recovery rate of GABA was in the range of 98.77% to 100.50%. The average content of GABA was 0.93 mg/g and Cheongju showed highest GABA content of 1.88 mg/g. As the time of harvest increased from May to September, the GABA content decreased from 1.56 to 0.86 mg/g. Also, maturation of the bitter melon fruit was associated with a decreased in GABA content.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.207-212
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• 2007

This study describes a simple and rapid method for quantitative determination of $\gamma$-aminobutyric acid (GABA) using $^1H$ NMR spectroscopy from whole cell extracts of plant suspension cultures. When 9 cell lines derived from 8 species of higher plants maintained in liquid Marashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) were subjected to $^1H$ NMR, a cell line of Coriandrum sativum L. exhibited the highest level of GABA. The level reached up to 16.9 mg/dry wt when cells were cultured in MS medium supplemented with 0.5 mg/L 2,4-D after 3 weeks of incubation. The method for quantitative determination of GABA using $^1H$ NMR established in this study could be applied to high-throughput screening of various plant resources for GABA production and the cell suspension culture system of C. sativum could be further developed for commercial production of GABA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.144-150
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• 2012

${\gamma}$-Aminobutyric acid (GABA) is a non-protein amino acid that is widely distributed in plant and animal kingdom. GABA is found in tissues of the central nervous system (CNS) in animals. GABA functions as a the major inhibitory neurotransmitter in the CNS by acting through the GABA receptors. Clinical studies have revealed the relationship between an increased intake of GABA or analogues with several health benefits, including lowering of blood pressure in mildly hypertensive animals and humans. Furthermore, GABA would also has an inhibitory effect on cancer cell proliferation, stimulates cancer cell apoptosis and plays a role in alcohol-associated diseases and schizophrenia. In plants, interest in the GABA emerged mainly from experimental observations that GABA is largely and rapidly produced in large amounts in response to biotic and abiotic stresses. In this study, we speculated the properties and metabolism of GABA in plant and functions in relation to the responses to environmental stresses.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1661-1669
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• 2007

Gamma-aminobutyric acid (GABA) is a non-protein amino acid. It is well known for its role as an inhibitory neurotransmitter of developing and operating nervous systems in brains. In this study, a novel function of GABA in the healing process of cutaneous wounds was presented regarding anti-inflammation and fibroblast cell proliferation. The cell proliferation activity of GABA was verified through an MTT assay using murine fibroblast NIH3T3 cells. It was observed that GABA significantly inhibited the mRNA expression of iNOS, IL-$1{\beta}$, and TNF-${\alpha}$ in LPS-stimulated RAW 264.7 cells. To evaluate in vivo activity of GABA in wound healing, excisional open wounds were made on the dorsal sides of Sprague-Dawley rats under anesthesia, and the healing of the wounds was apparently assessed. The molecular aspects of the healing process were also investigated by hematoxylineosin staining of the healed skin, displaying the degrees of re-epithelialization and linear alignment of the granulation tissue, and immunostaining and RT-PCR analyses of fibroblast growth factor and platelet-derived growth factor, implying extracellular matrix synthesis and remodeling of the skin. The GABA treatment was effective to accelerate the healing process by suppressing inflammation and stimulating re-epithelialization, compared with the epidermal growth factor treatment. The healing effect of GABA was remarkable at the early stage of wound healing, which resulted in significant reduction of the whole healing period.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.51-56
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• 1967

In order to find out the effects of GABA on the rabbit's intestinal motility, the following experiments were carried out using Magnus method and the results obtained were as follows: 1. GABA inhibited the intestinal motility of rabbits initially. 2. GABA potentiated the inhibitory action of adrenaline and nor-adrenaline. 3. GABA inhibited the accelerating activity of acetylcholine on the intestinal motility by its anti acetylcholine effect. 4. The inhibitory action of GABA was unaffected with atropinization, strychnin, picrotoxin treatment, but the accelerating activity of GABA observed in some cases was only in the picrotoxin treatment.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.26-33
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• 2016

Dominant lactic acid bacteria (LAB) strains were isolated from traditional fermented foods to obtain rare ${\gamma}$-aminobutyric acid (GABA)-producing LAB. Out of 147 isolates, 23 strains that could produce GABA with 1% (w/v) L-monosodium glutamate (MSG) were first isolated. After further screening of these rare GABA-producing LAB by analysis of the glutamate decarboxylase and 16S rRNA gene sequences, Enterococcus faecium JK29 was isolated, and 1.56 mM of GABA was produced after 48 h cultivation in basic de Man, Rogosa, and Sharpe (MRS) medium. To enhance GABA production by E. faecium JK29, the culture conditions were optimized. When E. faecium JK29 was cultivated in optimized MRS medium containing 0.5% (w/v) sucrose and 2% (w/v) yeast extract with 0.5% (w/v) MSG, GABA production reached 14.86 mM after 48 h cultivation at initial conditions of pH 7.5 and $30^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.979-985
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• 2017

This study was carried out to investigate the production of ${\gamma}$-aminobutyric acid (GABA) by lactic acid bacteria and to manufacture GABA using rice bran extract-based optimum medium. Electrostatic spraying technology was used to add GABA into the cereals. The isolated Lactobacillus brevis CFM11 produced the highest GABA production up to a concentration of $2,002.93{\mu}g/mL$ when cultivated in MRS broth containing 0.8% monosodium glutamate (MSG). The production level of GABA was $585.80{\mu}g/mL$ in rice bran extract containing 0.4% MSG, 2% sucrose, 1% skim milk, and 0.2% magnesium sulfate. After electrostatic spraying of the cultured suspension onto rice, GABA concentration reached $228.10{\mu}g/g$ while untreated rice reached $32.23{\mu}g/g$. These results demonstrate that rice bran extract can be an economic commercial medium for GABA production as a substitute for MRS broth. This study demonstrates the novel application of electrostatic spraying of GABA into cereal products for the first time.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.632-636
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• 2010

The level of ${\gamma}$-aminobutyric acid (GABA) in pigmented rice was quantitatively and qualitatively determined by high pressure liquid chromatography/fluorescence detection (HPLC/FLD). In this study, the recovery rate and limit of detection (LOD) of GABA were 122.4${\pm}$2.4% and 0.23 ${\mu}g/g$, respectively. The geminating pigmented rice samples, which were harvested in Paju, Korea, were soaked in water at $18^{\circ}C$ for 20 hr. After soaking, the samples were germinated at $30^{\circ}C$ for about 24 hr. GABA content was highest (293.0 ${\mu}g/g$) in the germinated red rice. Furthermore, GABA levels in the germinated rice increased significantly by up to 11.1 and 24.7-fold as compared to non-germinated rice and milled rice, respectively. The GABA concentrations of non-germinated rice, with the exception of red rice, were significantly higher than those of milled rice by 7.6-20.6-fold.