• Journal of the Korean Chemical Society
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• v.24 no.4
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• pp.315-321
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• 1980

A steady-state kinetic study on a dye-coupled cytoplasmic polyol dehydrogenase from G. melanogenus was carried by the initial velocity measurements in the direction of the polyol oxidation and the product inhibition by D-fructose. For the initial rate experiments, D-mannitol and D-sorbitol were employed as the specific polyol substrates and 2,6-dichlorophenolin-dophenol (DPIP) as the specific cofactor substrate for the enzyme. When the polyol and DPIP were examined by varying one of substrates and by fixing the second, the corresponding reciprocal plots showed the typical parallel pattern. This suggests that the enzyme from G. melanogenus proceeds by a Ping Pong Bi-Bi mechanism in which the polyol may account as the first reactant-in, and the ketose formed as the first product-out, respectively. The product inhibition patterns obtained by D-fructose (one no-inhibition, one non-competitive, and two competitive) may also provide an additional conformatory evidence for the above mechanism. Based on the kinetic parameters obtained, it was also suggested that the rate-limiting step in the direction of polyol oxidation is associated with the release of the ketose from the Enzyme${\cdot}$Polyol complex.

• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.189-193
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• 2000

Preservative and antimutagenic effects of green tea leaves added Chinese cabbage kimchi (GK1, GK2, GK3, and GK4 : 1, 2, 3 and 4 of green tea leaves (GTL) in proportion of 100 of salted Chinese cabbage were added to kimchi) were compared to those of the Chinese cabbage kimchi without GTL (control kimchi, CK). Fermentation period of GKs was further delayed than that of CK. The initial pH and acidity between GKs an CK were similar, but the time reach optimally ripened status of kimchi (pH 4.3) was different. CK took 6 days, while GK1, GK2, GK3 and GK4 took 6, 10, 12 and 14 days at 10℃, respectively. The growth of Leuconostoc sp. and Lactobacilus sp. in GKs delayed comparing to those in FCK. Among GKs, as the added amount of green tea leaves increased, the growth of lactic acid bacteria was retarded. The antimutagenic effects of juices from GKs and CK were studied against aflatoxin B₁(AFB₁) in the Ames test on Salmonella typehimurium TA100 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the SOS chromotest using E. coli PQ37. Juices from optimally ripened GKs (pH 4.3) showed 52∼76% inhibition rates against the indirect mutagen, aflatoxin B₁ induced mutagenicity while 49% inhibition rate by CK in the Ames test. Juices from GKs and CK showed 44∼67% and 36% inhibition rate against direct mutagen, MNNG (70 ng/assay) induce mutagenicity in the SOS chromotest. Thus GKs delayed fermentation period of kimchi and exhibited higher antimutagenic activity than CK.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.75-82
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• 2016

Paroxetine, a selective serotonin reuptake inhibitor (SSRI), has been reported to have an effect on several ion channels including human ether-a-go-go-related gene in a SSRI-independent manner. These results suggest that paroxetine may cause side effects on cardiac system. In this study, we investigated the effect of paroxetine on Kv1.5, which is one of cardiac ion channels. The action of paroxetine on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Paroxetine reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an $IC_{50}$ value and a Hill coefficient of $4.11{\mu}M$ and 0.98, respectively. Paroxetine accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -30 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to 0 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance ${\delta}$ of 0.32. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for paroxetine-induced block of Kv1.5 were $4.9{\mu}M^{-1}s^{-1}$ and $16.1s^{-1}$, respectively. The theoretical $K_D$ value derived by $k_{-1}/k_{+1}$ yielded $3.3{\mu}M$. Paroxetine slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of paroxetine, were superimposed. Inhibition of Kv1.5 by paroxetine was use-dependent. The present results suggest that paroxetine acts on Kv1.5 currents as an open-channel blocker.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5773-5778
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• 2011

Results regarding the anti-oxidative, anti-allergic, anti-bacterial and anti-cancer effects of lotus leaf and dandelion have been reported through active research on the medical effects of medicine prepared from crude drugs. This paper aimed to examine the anti-bacterial effect of lotus leaf and dandelion extracts on S. mutans by evaluating the colony forming unit and growth curve. In accordance with the growth inhibition rate of S. mutans according to the addition of lotus leaf and dandelion extracts, the higher the extract concentration was, the higher the growth inhibition rate of S. mutans was. This paper therefore verifies that lotus leaf and dandelion extracts have an effect in inhibiting the growth of S. mutans.

• Food Engineering Progress
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• v.13 no.3
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• pp.216-220
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• 2009

The several functional properties of freeze-dried powder of Aloe vera gel was examined as influenced by pre-concentration degrees of the gel solution. As a pre-treatment prior to freeze drying, the gel solution was vacuum-concentrated by three levels (unit: g-water/g-solids) - high (H), 76; medium (M), 119; low (L), 159. In FT-IR spectra, the sample H showed the highest absorbance in the range of 1600-1550 $cm^{-1}$ and 1450-1400 $cm^{-1}$, which corresponded to level of the acetyl group in glucomannan. The sample H of freeze-dried powder was the highest in polysaccharide content, jack bean urease inhibition rate, and FAC (fat adsorption capacity). It could be inferred that the sample H had an effect on Helicobacter pylori inhibition and fat adsorption suppression according to urease inhibition rate and FAC, respectively.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.461-465
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• 1998

The suspension culture of an anchorage-dependent cell line (Bok-l) from Bombina orientalis was successful in respects of cost and efficiency. The amount of cells obtained from the suspension culture was almost equivalent to that from the anchorage-dependent culture. This result shows the possibility of suspension culture for scale-up. The cells in suspension produced an antibacterial peptide as much as anchorage-dependent cells did. The cell growth ($6.0\times10^6cells/m\ell$) and viability (>80%) at 10 rpm were higher than that at 0 rpm ($1.9\times10^6cells/m\ell$, 65~80%) and 30 rpm ($1.8\times10^6cells/m\ell$ 40~76%). The size of cells became smaller at the agitation rate of 30 rpm. The antibacterial activities of cell extracts from suspension cultured cells were confirmed against gram-negative and gram-positive bacteria by the inhibition zone assay and the liquid growth inhibition assay.

• Corrosion Science and Technology
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• v.17 no.5
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• pp.225-230
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• 2018

The effects of birch sap, a possible natural corrosion inhibitor, on the corrosion behavior of steel in chloride solution were investigated. The corrosion rate was significantly reduced by the addition of 1~5 mL of birch sap to 500 mL of 3wt% NaCl or 3wt% $CaCl_2$ solution. A remarkable increase in the pitting potential in NaCl solution was observed by the addition of birch sap although it was almost constant in $CaCl_2$ solution. The corrosion rate of steel in both NaCl and $CaCl_2$ birch sap solution without addition of water was higher compared to that of aqueous solution without birch sap as the pH of the birch sap was 4.0. The presence of organic compounds like, fructose, galactose, glucose, and palmitic acid in the birch sap are thought to be adsorbed effectively on the metal surface, which provided corrosion protection. However, the inorganic elements including Na, Ca, K, Mg, Mn, S, etc. present in the birch sap exhibited no role in corrosion inhibition.

• Applied Microscopy
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• v.17 no.2
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• pp.55-71
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• 1987

To investigate the effects of lead on the electron transport system and ultrastructure of mouse kidney mitochondria, various lead acetate concentrations were treated in vitro and respiration rate, enzyme activities were measured. Ultrastructural changes at state IV respiration were also observed. To compare with in vivo experiments, mouse were injected intraperitoneally of 100 mg lead acetate per kg body weight and state IV respiration rate and enzyme activities were measured. Ultrastructure of renal proximal tubular cells were also observed. In in vitro treatement, decreased state IV respiration, decreased enzyme activities, ruptured membranes and inhibition of condensed to orthodox transformation were observed. In in vivo treatment, decreased state IV respiration and decreased enzyme activities were observed after 24 hrs of i.p. injection. Cytochrome c oxidase activity showed twice the inhibition compared to NADH-CoQ reductase activity at 24 hrs. Continuous decreased state IV respiration was observed after 48 and 72 hrs of injection, however, the enzyme activities were increased to control level. Lead-protein complex which probably inhibits the toxic effects of lead appeared. To conclude, dominant effect of lead on the electron transport system appeared at cytochrome c oxidase activity, and the increased enzyme activities may be a result of appearance of lead-protein complex.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.229-233
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• 2015

The anti-nociceptive effect of an ethanol extract and its various solvent fractions from Curcuma longa Linne ethanol extract was studied using the writhing test in mice. Different fractions by various solvent extraction from Curcuma longa Linne ethanol extract were administered orally 1 hr or time-course (0.5, 1, 2 and 5 hr) before intraperitoneal injection of acetic acid. After treatment with 30% ethanol extract and n-butanol fraction, CB-1, at a dose of 250 mg/kg, the significant writhing responses were 87.5 ± 13.4 (inhibition rate 31%, p<0.01) and 75.1 ± 11.1 (inhibition rate 41%, p<0.01) lower than the control group. At the dose of CB-1 50 mg/kg and 250 mg/kg, CB-1 showed a similar activity comparing to diclofenac of 10 mg/kg. A time-course experiment was performed, which involved oral administration of CB-1 (250 mg/kg) at 0, 0.5, 1, 2, and 5 hr before acetic acid intraperitoneal injection. The most effective time of CB-1 was 30 min before treatment and persisting until 2 hr. This study showed that Curcuma longa Linne has anti-nociceptive properties comparable with those of diclofenac, which suggests promise for the treatment of intractable visceral pain in humans. Major components of the active fraction are identified as curcumin, cyclocurcumin and demethoxycurcumin.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.3
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• pp.77-91
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• 2005

Purpose : Trichosanthis Radix is traditional medical herb which has been shown to inhibit tumor cell proliferation. In this study, the effects of Trichosanthis Radix extract were investigated on inducing growth inhibition and apoptosis of human uterine cervical carcinoma cells. Methods : Human uterine cervical carcinoma cells line, ME-180, was used for the study. The cells were treated with varying concentrations of Trichosanthis Radix extract. Cell growth and inhibitory rate were measured by MTT assay. Apoptosis induction was detected by fluorescence microscopy, DNA ladder formation and flow cytometry. Results : Trichosanthis Radix extract inhibited the growth of human uterine cervical carcinoma cells in a dose-dependent manner. It induced ME-180 cells to undergo apoptosis including fragmented nuclei and nucleosome-sized DNA fragmentation. Flow cytometric analysis showed the increasing rate of apoptotic cells by Trichosanthis Radix extract. Reduction of mitochondrial membrane potential and increase in caspase-3 activity and were found in ME-180 cells treated with Trichosanthis Radix extract. Conclusion : Our data suggest that Trichosanthis Radix extract inhibit the growth and proliferation of ME-180 cells by apoptotic induction and facilitates its activity via caspase-3 activation initiated by depolarization of mitochondria.