• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.265-270
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• 2017

A key virulence factor for urinary tract pathogens is the enzyme urease, which catalyzes the hydrolysis of urea into ammonium ions and carbonic acid. Urease activity plays an important role in the pathogenesis of urinary tract infection. In this study, the inhibitory effect of zerumbone against six urease-producing bacteria (Klebsiella oxytoca, K. pneumoniae, Morganella morganii, Proteus mirabilis, P. vulgaris, and Staphylococcus saprophyticus) and their urease activities were evaluated. The results of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests showed that zerumbone had antibacterial effect against these six urease-producing bacteria. The MIC and MBC of zerumbone ranged from 0.5 to 2 mM and 1 to 4 mM, respectively. In the urease inhibitory assay, zerumbone showed better urease inhibition ($56.28{\pm}2.45-37.83{\pm}3.47%$) than the standard urease inhibitor, acetohydroxamic acid ($40.46{\pm}1.94-22.99{\pm}3.53%$). However, zerumbone did not affect the levels of the urease subunit. These results clearly indicated that zerumbone has antibacterial potential against urease-producing bacteria and possesses excellent bacterial urease inhibition properties.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3147-3149
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• 2009

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.447-449
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• 1996

Inhibitory effects of the mushrooms on the growth and urease of Helicobacter pylori (HP), which is associated with human gastroduodenal diseases such as gastritis, peptic ulcer and gastric carcinoma, were investigated. Most of the mushroom extracts did not show inhibitory effect on HP urease except Coriolus versicolar, Auricularia auricular Sarcodon aspratus and Flammulina velutipes. The extract of Ganoderma lucidum, Coriolus versicolar, Gyropora esculenta and Agaricus bisporus var. albidus inhibited the growth of HP. When their extracts were fractionated, the ether fraction of Ganoderma lucidum and Agaricus bisporus var. albidus were the most effective. Among seven components separated from the ether fraction of G. lucidum extract by silica gel column chromatography, P3 was the most potent: MIC was $200{\mu}g/ml$. However, P3 did not inhibit the urease.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.334-344
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• 2014

The objective of this study was to evaluate the microbiological and physicochemical characteristics, and the antagonistic activity against Helicobacter pylori ATCC 43504, of yogurt fermented with the lactic acid bacteria from Baikkimchi kept under cold storage. The viable cell counts, titratable acidity, viscosity, and total solid content of the yogurt were different according to the bacterial strains used for fermentation. There was no significant change (P>0.05) in the various properties of refrigerated yogurt. Among the tested strains, the strongest resistance against artificial gastric juice and bile salt was found for Lactobacillus brevis BK11 and Lactobacillus paracasei BK57. Due to high lactic acid levels obtained from these two lactic acid bacteria, yogurt may show good anti-Helicobacter effects according to the time-kill assay. In particular, yogurt fermented with L. brevis BK11 significantly reduced the number of H. pylori adhering to gastric epithelial AGS cells and the urease activity of this pathogen (P<0.05).

• Korean Journal of Veterinary Research
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• v.52 no.2
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• pp.105-113
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• 2012

In this study, a medicinal herbal plant, Meliae fructus, was examined and screened for anti-Helicobacter (H.) pylori activity. Seventy percent ethanol was used for herbal extraction. For anti-H. pylori activity screening, inhibitory zone tests as an in vitro assay and in vivo study using a Mongolian gerbil (Meriones unguiculatus) model were performed. Also, the safety of herbal compounds was evaluated by animal study. As a result of inhibitory zone test, Meliae fructus extract demonstrated strong anti-H. pylori activities. Also, as results of in vivo animal studies, Meliae fructus demonstrated strong therapeutic effects against H. pylori infection according to the criteria of histological examination and rapid urease test. As results of the safety study, after 28 days treatment of the Meliae fructus extract, the animals were not detected any grossly and histological changes. These results demonstrate that it can be successfully cured against H. pylori infection and protected from H. pylori-induced pathology with Meliae fructus. It could be a promising native herbal treatment for patients with gastric complaints including gastric ulcer caused by H. pylori.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.156-168
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• 2015

The objective of this study is to investigate the anti-Helicobacter pylori and anti-cancer activities of the live cells (LC), cell-free culture supernatants (CFCS), and bacteriocin solution (BS) obtained from Lactobacillus acidophilus BK13 and Lactobacillus paracasei BK57 strains. After incubation for 30 h in MRS broth, the concentration of lactic acid produced by L. paracasei BK57 ($155.9{\pm}10.2mM$) was higher than in MRS broth using L. acidophilus BK13 ($126.8{\pm}7.9mM$). Maximum bacteriocin activity (128 AU/ml) of BK13 strain was observed after 30 h of cultivation at $37^{\circ}C$, however its magnitude was significantly lower than that of BK57 strain (256 AU/ml). The LC of L. acidophilus BK13 and L. paracasei BK57 were able to inhibit the growth of H. pylori ATCC 43504 at different incubation times, depending on the initial inoculum of the LAB. These CFCS and BS obtained from BK13 and BK57 strains dramatically inhibited the growth, adhesive ability, and enzymatic activity of H. pylori. Meanwhile, the anti-cancer effect of the lactic acid from L. acidophilus BK13 and L. paracasei BK57 strains on AGS cells had significant differences with the control group. Therefore, these antagonistic substances-producing strains are potentially useful as new potential antimicrobial agents for the management and prevention of H. pylori infections.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.152-156
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• 2005

In the present study, lactic acid bacterium that has antibacterial activity against Helicobacter pylori was isolated from feces of newborn baby. The selection was based on the ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions such as acidic pH and high bile concentration. By biochemical test and 16S rDNA sequencing, selected strain was turned out to be an Pediococcus acidilactici, therefore designated to P. acidilactici GMB7330. In order to investigate the inhibitory effects of P. acidilactici GMB7330 on the growth of H. pylori, we have tested in vitro studies such as cell viability and urease test. These results showed that antibacterial activity of P. acidilactici GMB7330 significantly decreased the viable cell count and urease activity of H. pylori. Antibacterial activity of P. acidilactici GMB7330 against H. pylori remained after pH adjustment to neutral, and the concentration of lactate produced from P. acidilactici GMB7330 was not enough to inhibit H. pylori. On the basis of the analysis by transmission electron microscope, it demonstrated that addition of P. acidilactici GMB7330 destroyed the cell structure of H. pylori. These results strongly suggested that P. acidilactici GMB7330 produce antibacterial substances to be able to inhibit the growth of H. pylori other than lactic acid.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.106-114
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• 2008

One bacterium, which showed strong antagonistic activity against H. pylori KCCM 41756, was isolated from kimchi. The strain NO1 was designated as Lactobacillus plantarum NO1 based on Gram staining, biochemical properties, and 16S rRNA gene sequencing. The culture medium $(2{\sim}4{\mu}g/ml)$ of Lb. plantarum NO1 reduced $(40{\sim}60%)$ the urease activity of H. pylori KCCM 41756. Lb. plantarum NO1 inhibited the binding of H. pylori to human gastric cancer cell line, AGS cells, by more than 33%. Lb. plantarum NO1 exhibited high viability (maintained initial viable cell count of $10^9CFU/ml$) in 0.05 M sodium phosphate buffer (pH 3.0) for 2 h, in artificial gastricjuice for 2 h and in 0.3%, 0.5% oxgall for 24 h. Hemolysis phenomena did not observed when Lb. plantarum NO1 was incubated in the blood agar media. We concluded that Lb. plantarum NO1 can be a good candidate as a probiotic, harboring anti-H. pylori activity.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.532-534
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• 2000

The inhibitory effects of different Bifidobacterium spp. on the growth of Helicobacter pylori (HP) were investigated. A significant suppression of HP growth occurred only when HP was inoculated onto a petri dish containing 0.1 mg/ml of Bifidobacterium spp. When HP was separately cultured with B. breve K-110, B. catenulatum K-309, B magnum K-311, B. magnum K-321, and B. cuniculi K-513, the urease activity was also inhibited by these Bifidobacterium spp. Therefore, it appears that these Bifidobacterium spp. excrete a heat-labile inhibitory component for HP growth into the culture medium. Although most organic acids produced by the Bifidobacterium spp. inhibited the growth of HP, the HP growth was not inhibited by the physiological concentrations of organic acids produced in bifidobacteria-cultured media. Accordingly, these results suggest that some Bifidobacterium spp. may produce antibiotic-like compounds (bacteriocins).

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.84-89
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• 2005

Mongolian dandelion (Taraxacum mongolicum H.) extracted with solvents having different polarities were prepared to investigate protection activity of gastric mucosa. Ethanol extracts were successively reextracted with methylene chloride, and n-butanol. Concentrations of total flavonoids and luteolin in n-butanol extracts were 27.75 and 1.14%, respectively, much higher than those of other solvent extracts. Results of anti-microbial acitivity test against Helicobacter pylori and urease inhibition test revealed n-butanol extract exerted higher inhibition (13.16%) than other solvent extracts. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, n-butanol extract showed the highest efficiency of free radical-scavenger activity among the extracts ($SC_{50}\;47{\mu}g/mL$). Erythrocytic photohemolysis tests, for the protection of cell membrane showed that half-life of human erythrocytes was increased by the addition of n-butanol extract $({\tau}_{50}=172min;C=5.0{\mu}g/mL)$. These results indicate n-butanol extract of Mongolian dandelion may be useful as a adjuvant for gastric diseases.