• Biomolecules & Therapeutics
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• v.11 no.3
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• pp.169-173
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• 2003

Alkylthioureido-1,3-propandiols (KY353X series) were synthesized and evaluated as inhibitors for neutral sphingomyelinase (N-SMase). To examine whether KY353X series inhibit N-SMase, we purified the N-SMase from bovine brain. The N-SMase was partially purified by sequential chromatographies of DEAE-Cellulose anionic exchange and phenyl-5PW hydrophobic HPLC. These seqeuntial procedures for N-SMase resulted in a 67-fold purification and excluded other isoforms of SMase. Based on in vitro assay, KY353X series inhibited N-SMase activity in time, concentration-dependent manners and completely inactivated N-SMase at 50 $\mu$M. In particular, KY3535 and KY3536 inhibited more effectively than the others. To further determine the .inhibitory pattern, a Dixon plot was constructed, to showing that the inhibition by KY3535 and KY3536 were competitive. The inhibition constant (Ki) of KY3535 and KY3536 was 1.7 $\mu$M and 2.5$\mu$M in 100 mM Tris-HCl buffer, pH 7.0, respectively.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.710-719
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• 2022

This study attempted to investigate the possibility of Passiflora caerulea extract as a cosmetic material by measuring its antioxidant activities and melanin biosynthesis-inhibiting effects. For this, the substance was extracted with 70% ethanol, and ABTS radical scavenging activities were measured, using the TEAC assay. In addition, cell viability through the neutral red assay, ROS inhibition and inhibition of melanin biosynthesis were analyzed, and the results found the followings: In terms of ABTS radical scavenging activities of the extract, dose-dependent scavenging activities were observed. In trolox used as a positive control group and 0.1 mg/mL, similar radical scavenging activities were found. The production of ROS through CFDA was inhibited in a dose-dependent fashion. Furthermore, inhibition of melanin biosynthesis induced by 𝛼-MSH was confirmed. Therefore, it is reasonable to conclude that Passiflora caerulea extract has a potential as a cosmetic ingredient.

• Biomedical Science Letters
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• v.24 no.3
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• pp.270-274
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• 2018

Chlorine dioxide ($ClO_2$) gas is a neutral chlorine compound. $ClO_2$ gas was proven to effectively decontaminate different environments, such as hospital rooms, ambulances, biosafety level 3 laboratories, and cafeterias. In this study, to evaluate the effects of $ClO_2$ gas, bacteria of clinical importance were applied. Staphylococci, Streptococci and Bacillus strains were applied and Klebsiella, and others e.g., Escherichia coli, Shigella, Salmonella, Serratia were also done for the inhibitory analysis. Bacteria plates were applied with a hygiene stick, namely, "FarmeTok (Medistick/Puristic)" to produce $ClO_2$. $ClO_2$-releasing hygiene stick showed the very strong inhibition of bacterial growth but had different inhibitions to the bacteria above 96.7% except for MRSA of 90% inhibition. It is difficult to explain why the MRSA were not inhibited less than others at this point. It can be only suggested that more releasing $ClO_2$ should be essential to kill or inhibit the MRSA. B. subtilis, S. agalactiae, S. pyogenes, E. coli O157:H7, S. typhi (S. enterica serotype typhi) and S. marcesence were inhibited over 99%. This study will provide fundamental data to research growth inhibition by $ClO_2$ gas with bacteria of clinical importance value.

• The Journal of Korean Physical Therapy
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• v.32 no.6
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• pp.325-328
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• 2020

Purpose: This study examined the effects of the directions of neck rotation position on the muscle activity and strength of the elbow flexor and extensor muscle. Methods: Forty-one healthy adults participated in this study. The subjects were asked to their elbow 90° flexion in three different neck rotations (neutral, ipsilateral, and contralateral) in the sitting position. The muscle activities of the biceps and triceps brachii muscle were measured using surface electromyography. And the muscle strength of the elbow flexor was measured using dynamometer. One way repeated measures ANOVA was used to compare the muscle activity and strength of the elbow flexor and extensor depending on the different neck turning directions. Results: There were significant differences between contralateral neck rotation and ipsilateral neck rotation, contralateral neck rotation and neutral position. But, there was no significant difference in the triceps brachii muscle activity in comparison with the neck rotation. There were significant differences between contralateral neck rotation and ipsilateral neck rotation, contralateral neck rotation and neutral position. Conclusion: To summarize this study, the elbow flexor and extensor muscle activity and strength was highest in the contralateral neck rotation position. In other words, it was possible to confirm the effect of Asymmetrical Tonic Neck Reflex in healthy adults whose primitive reflexes were inhibition, and head and neck positions should be considered during clinical evaluation and treatment.

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.109-113
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• 2000

In this study, a potential mechanism through which the hesperidin might work on the effect was examined in vivo. Male rats were fed a high cholesterol synthetic diet (1%, wt/wt) with hesperidin (0.1%, wt/wt) for 42 days. Activity of hepatic HMG-CoA reductase was significantly lowered by the hesperidin supplement compared to the control. Hesperidin did not significantly alter plasma or hepatic lipids, but tended to lower those lipid levels. Hesperidin also subsequently reduced the fecal neutral sterols compared to the control(253.3mg/d vs.521.9 mg/d). The inhibition of HMG-CoA reductase resulting from the hesperidin supplementation could count for the reduction in fecal neutral sterols that appears to compensate for the decreased cholesterol biosynthesis. The dose of hesperidin in a high choles-terol diet should apparently be more than 0.1% to exhibit the hypocholesterolemic response in these rats. It remains to be determined whether the observed alterations in cholesterol metabolism are specific to the rat or also could be applied to the humans.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.265-269
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• 1999

Transgenic tobacco plants expressing either a sweet potato anionic peroxidase (POD) (swpal) or neutral POD (swpnl) were irradiated by gamma radiation, and the gamma radiation-induced biochemical changes in antioxidant enzymes and plant growth inhibition were investigated at 30 days after treatment. Gamma radiation significantly inhibited the growth of all plants regardless of transgenic or nontransformed plants, showing a dose-dependent inhibition. In high dosage of 50 and 70 Gy, plant heights were severely retarded and new leaves does not emerged. No significant changes in antioxidant enzymes such as POD, superoxide dismutase and catalase were observed in all plants regardless of irradiation dosages ranging from 10 to 50 Gy. These results suggest that sweet potato PODs may be not involved in the protection against the oxidative stress induced by gamma radiation.

• Corrosion Science and Technology
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• v.19 no.1
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• pp.8-15
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• 2020

In this paper, the efficiency and the inhibition mechanisms of cobalt salts (cobalt nitrate and cobalt-exchange silica Co/Si) for the corrosion protection of AA2024 were investigated in a neutral aqueous solution by using the electrochemical impedance spectroscopy (EIS) and polarization curves. The experimental measurements suggest that cobalt cation plays a role as a cathodic inhibitor. The efficiency of cobalt cation was important at the concentration range from 0.001 to 0.01 M. The formation of precipitates of oxides/hydroxides of cobalt on the surface at low inhibitor concentration was confirmed by the Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM/EDS) analysis. EIS measurements were also conducted for the AA2024 surface covered by water-based epoxy coating comprising Co/Si salt. The results obtained from exposure in the electrolyte demonstrated the improvement of the barrier and inhibition properties of the coating exposed in the electrolyte solution for a lengthy time. The SEM/EDS analysis in artificial scribes of the coating after salt spray testing revealed the release of cobalt cations in the coating defect to induce the barrier layer on the exposed AA2024 substrate.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.185-193
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• 1997

The characteristics of $Na^+$-dependent cycloleucine uptake was investigated in OK cells with regard to substrate specificity and regulation by protein kinase C (PKC). Inhibition studies with different synthetic and natural amino acids showed a broad spectrum affinity to neutral amino acids regardless of their different side chains including branched or aromatic, indicating that the $Na^+$-dependent cycloleucine uptake in OK cells is mediated by System $B^o$ or System $B^o$-like transporter rather than the classical System A or ASC. Phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate, but not $4{\alpha}-PMA$ elicited a time-dependent biphasic stimulation of $Na^+$-dependent cycloleucine uptake, which produced early transient peak at 30 min and late sustained peak at 180min. Both the early and late stimulations by PMA were due to an increase in Vmax and not due to a change in Km. PKC inhibitors blocked both the early and late stimulation by PMA, while protein synthesis inhibitors blocked the late stimulation only. These results suggest the existence and regulation by PKC of System $B^o$ or System $B^o$-like broad spectrum transport system for neutral amino acids in OK cells.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.19-30
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• 2005

This study was to evaluate the biological activity of flavor components extracted from E. ciliata and E. splendens in order to survey the possibility applicable to tobacco and food industry. Flavor components were extracted with dividing into three parts; essential oil, absolute, oleoresin. In the nonenzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil were $67.3\;\pm\;20.7\%,\;58.1\;\pm\;19.3\%$ at the concentration of 50 ${\mu}g/mL$ of E. ciliata and E. splendens, respectively. The inhibition rate($\%$) of the oleoresin in E. ciliata was higher than one in E. splendens. In the enzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil and oleoresin was$14.28\;\pm\;2.38\%,\;and\;65.93\;\pm\;0.01\%,\;and\;was\;22.58\;\pm\;2.84\%\;and\;40.73\;pm\;6.04\%$. The oleoresin of two species were showed above $90\%$ of the inhibition rate($90\%$) against autooxidative lipid peroxidation system. $EC_{50}$ values in neutral red uptake assays 24 h of exposure times were $23.3\;{\mu}g/mL,\;341.0\;{\mu}g/mL\;and\;17.2\;{\mu}g/mL$ in essential oil, absolute and oleoresin from E. ciliata respectively, and were $46.4\;{\mu}g/mL,\;681.7\;{\mu}g/mL\;17.6\;{\mu}g/mL$ in three extractions of E. splendens. Oleoresin of two species showed high rate in the cytotoxic effect by neutral red uptake assay. Absolute and oleoresin did not show antibiotic and mutagenic activity. On the contrary, essential oil with over 500 ug/plate showed antibiotic and mutagenic activity in Ames test. Essential oil and oleoresin have a prolongating effect the ciliostasis of rat trachea. This results indicate that flavor components extracted from E. ciliata and E. splendens can be considered to be toxicological safe and to be the possibility applicable the cigarette, food and drug industry as a flavor for expectoration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.758-763
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• 2003

Amino acid transporters play an important role in supplying nutrients to normal and cancer cells for cell proliferation. System L is a major transport system responsible for the N $a^{＋}$-independent, large neutral amino acids including several essential amino acids. L-type amino acid transporter 1 (LAT1), an isoform of system L amino acid transporter, is highly expressed presumably to support their continuous growth and proliferation in malignant tumors. 2-Aminobicyclo- (2,2,1) -heptane-2-carboxylic acid (BCH) is a model compound for study of amino acid transporter as a system L selective inhibitor. In the present study, we examined whether BCH induced growth inhibition in KB human oral squamous carcinoma cell line or not. The uptake of L-［$^{14}$ C］leucine by KB cells is inhibited by BCH in a concentration dependent manner with a Ι $C_{50}$ value of 75.3$\pm$6.2 ${\mu}{\textrm}{m}$ and a $K_{i}$ value of 98.7$\pm$ 4.1 ${\mu}{\textrm}{m}$. The growth of KB cells is inhibited by BCH in time dependent manner and concentration dependent manner with a Ι $C_{50}$ value of 11.1 $\pm$0.8 mM. In the DNA of KB cells treated with the various concentrations and various periods of BCH, the characteristic ladders associated with DNA fragmentation were not observed. These results suggest that BCH inhibits the growth of KB oral epidermoid carcinoma cells through the inhibition of transport of neutral amino acids into cells without DNA break down. This phenomenon will be a new rationale for anti-cancer therapy.y.