• Korean Journal of Pharmacognosy
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• 제30권3호
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• pp.255-260
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• 1999

In the previous report, E-kong-san, which is usually used for recovering health in traditional medicine, has been shown to decrease cisplatin induced nephrotoxicity in vivo and in vitro. The significant reduction of E-kong-san on the cisplatin induced nephrotoxicity led us to investigate whether the effect of this water extract was a result of triggering antioxidation. In monkey kidney Vero cells, E-kong-san at $5{\sim}10\;mg/ml$ was able to attenuate 2mM cisplatin-stimulated cell death by 46.8% and 31.8%, respectively. E-kong-san showed strong free radical scavengering activities on 1,1-diphenyl-2-picrylhydrazil (DPPH) radical and xanthine/xanthine oxidase (XOD) generated superoxide anion radical $(O_2^{-.})$. We further studied the effects of E-kong-san on lipid peroxidation in rat liver microsomes induced by enzymatic and nonenzymatic methods. Moreover, E-kong-san exhibited significant inhibition on both ascorbic $acid/Fe^{2+}$ and $ADP/NADPH/Fe^{3+}$ induced lipid peroxidation in rat liver microsomes. Based on these results, we suggest that E-kong-san protects the cisplatin induced cytotoxicity by its antioxidative mechanism.

• Korean Journal of Acupuncture
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• 제28권4호
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• pp.29-40
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• 2011

Objectives : This study estimated antioxidant effects of the moxi with ginger tar (MGT) ; chemical combustion products produced by moxibustion with ginger during combustion. Methods : To do this aim, we investigated total polyphenol and flavonoid contents, SOD (superoxide dismutase) scavenging activity, ABTS (2.2-azino-bis-3-erthylbenzo-thiazoline-6- sulfonic acid) & DPPH(2,2-Dipheny1-1 -picryl-hydrazyl) radical's scavenging ability of MGT. Results : Total polyphenol contents of MGT was $7.8{\pm}0.09$ mg/g in 10 mg/ml, SOD activity was $42.51{\pm}3.39%$ in 200 ug/ml, DPPH radical scavenging effect of MGT was $83.24{\pm}0.01%$ in 200 ug/ml and ABTS radical scavenging effect was $41.88{\pm}0.16%$ in 200 ug/ml. Conclusions : In this study, the effects of moxi with ginger could be induced by not only heating stimulus on acupoints but also chemical stimulus produced during combustion of moxibustion, MGF. The advanced study about biological mechanism through meridian system, skin aging, and inflammation on MGT will be required.

• Journal of Ginseng Research
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• 제41권2호
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• pp.188-194
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• 2017

Background: Fermented black ginseng (FBG) is processed ginseng by the repeated heat treatment and fermentation of raw ginseng. The protective effect and mechanism of FBG on cisplatin-induced nephrotoxicity was investigated to evaluate its therapeutic potential. Methods: The free radical scavenging activity of FBG was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH). In addition, the protective effect against cisplatin-induced renal damage was tested in rats. FBG was orally administered every day at a dose of 150 mg/kg body weight for 10 d, and a single dose of cisplatin was administered intraperitoneally (7.5 mg/kg body weight) with 0.9% saline on the $4^{th}$ d. Results: The DPPH radical-scavenging activity of FBG ($IC_{50}=384{\mu}g/mL$) was stronger than that of raw ginseng. The improved DPPH radical-scavenging activity was mediated by the generation phenolic compounds. The decreased cell viability by cisplatin was recovered significantly after treatment with FBG in a dose-dependent manner. Then, the protective effect of FBG on cisplatin-induced oxidative renal damage was investigated in rats. The decreased creatinine clearance levels, which are a reliable marker for renal dysfunction in cisplatin-treated rats, were reduced to the normal level after the administration of FBG. Moreover, FBG showed protective effects against cisplatin-induced oxidative renal damage in rats through the inhibition of $NF-{\kappa}B/p65$, COX-2, and caspase-3 activation. Conclusion: These results collectively show that the therapeutic evidence for FBG ameliorates the nephrotoxicity via regulating oxidative stress, inflammation, and apoptosis.

• Food Science of Animal Resources
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• 제34권3호
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• pp.325-332
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• 2014

The antioxidant capacity of porcine splenic hydrolysate (PSH) was studied in vitro and in vivo. Peptide hydrolysates were prepared, using the proteolytic enzyme $Alcalase^{(R)}$. The molecular weights of PSH were 37,666, 10,673, 6,029, and 2,918 g/mol. Rats were fed a 5% (w/v) PSH diet, instead of a casein diet, for 4 wk. The food intake, body weight gain, and liver weight of rats in the PSH group were similar to those in the control (CONT) group. There were no differences in the serum total cholesterol, triglyceride, total protein, or albumin levels between PSH and CONT groups. However, the level of in vivo hepatic lipid peroxidation in PSH group was significantly lower than that in CONT. In vivo hepatic catalase and glutathione peroxidase activities in the PSH group were significantly higher than those in the control group. The in vitro protein digestibility of PSH was lower than that of casein. The in vitro trolox equivalent antioxidant capacity of PSH was significantly higher than that of the peptide hydrolysate from casein. The in vitro radical scavenging activities of PSH were significantly higher than those of the peptide hydrolysate from casein. The present findings suggest that porcine splenic peptides improve the antioxidant status in rats by enhancing hepatic catalase and GSH-Px activities, and indicate a potential mechanism of radical scavenging activity during gastrointestinal passage.

• Elastomers and Composites
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• 제55권1호
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• pp.51-58
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• 2020

In this study, the thermal oxidation of raw natural rubber (NR) was investigated under controlled conditions by optical image and fourier transform infrared (FT-IR) analysis. The thermal oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at 80℃ under low humidity conditions to completely exclude moisture and restrict light oxidation. Images of the thin film of raw NR were obtained before and after thermal oxidation. FT-IR absorption spectra were measured in the transmission mode at different thermal exposure times. The thermal oxidation of NR was examined by the changes in the absorption peaks at 3449, 1736, 1447, 1377, 1242, 1072, and 833 cm^-1, which corresponded to a hydroxyl group (-OH), a carbonyl group (-C=O) from an aldehyde and a ketone, a methylene group (-CH₂-), a methyl group (-CH₃), a carbon-oxygen single bond (-C-O) from an epoxide, a carbon-oxygen bond (-C-O) from an ether, an alcohol, a peroxide, or a cyclic peroxide, and a cis-methine group (cis-CCH₃=CH-), respectively. In the initial stage of thermal oxidation, two different types of free radicals were produced quickly and randomly by the homolytic cleavage of a double bond and allylic hydrogen abstraction. Aldehydes and ketones were formed from chain scissions of the double bonds and alcohols were produced from allylic hydrogen abstraction at the methylene or methyl groups. Two reactions seemed to proceed competitively with each other. At a later stage, oxidative crosslinks seemed to dominate through the combination of free radicals such as an allyl radical (CH=CHCH₂·), alkoxy radical (RO·), and peroxy radical (ROO·) and the reaction of a hydroperoxide (-ROOH) with a double bond. The image obtained after thermal oxidation showed hardening without cracks. Based on these observations, a plausible two-step mechanism was suggested for chain hardening caused by the thermal oxidation.

• Investigative and Clinical Urology
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• 제63권3호
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• pp.334-340
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• 2022

Purpose The prevalence of catheter-associated urinary tract infections (CAUTIs) varies from 5% to 8.2%, and the risk of infection increases by 5% to 7% per day of primary indwelling. We investigated whether a novel biofilm inhibitory mechanism using an inhibitory silicone urethral catheter (a coated Foley catheter) can reduce CAUTIs compared to conventional non-coated Foley catheters. Materials and Methods This study prospectively analyzed the difference in the incidence of CAUTIs in patients who underwent radical cystectomy with an orthotopic neobladder for bladder cancer and received a coated or conventional non-coated catheter. Additionally, differences in bacterial colonization between the groups were analyzed using a catheter-tip bacterial culture test. Results Eighty-five patients were randomized into the "coated Foley catheter" group (abbreviated as "case" group; 41 patients) and a control group (44 patients). The two groups were identical except for their surgical history. The incidence of CAUTIs 2 weeks after radical cystectomy was 21.95% (case) and 27.27% (control), with no significant difference between the two groups. However, when the catheter was removed 2 weeks after surgery, the catheter tip culture test revealed significant bacterial colonies in 25 (60.98%) and 38 (86.36%) patients in the case and control group, respectively. No catheter-related postoperative side effects were observed in either group. Conclusions The incidence of CAUTIs in the two groups did not differ according to the catheter material. However, the catheter bacterial culture test showed that bacterial colonization was significantly suppressed on the Bi-Fi Free technology catheter, which comparatively inhibited biofilm formation.

• Applied Chemistry for Engineering
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• 제29권1호
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• pp.49-55
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• 2018

In this study, we investigated the cellular protective effects and mechanisms of nicotiflorin and its aglycone kaempferol isolated from Annona muricata. The protective effect of these components against $^1O_2$-induced cell damage was also studied by using L-ascorbic acid and (+)-${\alpha}$-tocopherol as controls. Kaempferol exhibited the most potent protective effect, followed by (+)-${\alpha}$-tocopherol and nicotiflorin. L-Ascorbic acid did not exhibit any cellular protective effects. To elucidate the mechanism underlying protective effects, the quenching rate constant of the singlet oxygen, free radical-scavenging activity, ROS-scavenging activity, and uptake ratio of the erythrocyte membrane were measured. The results showed that the cell membrane penetration is a key factor determining the cellular protective effect of kaempferol and its glycoside nicotiflorin. The result from L-ascorbic acid demonstrated that the cellular protective effect of a compound depends on its ability to penetrate the cell membrane and is independent of its antioxidant capacity. In addition, it is suggested that cellular protective effects of kaempferol and (+)-${\alpha}$-tocopherol depend not only on the cell permeability, but also on free radical- and ROS-scavenging activities. These results indicate that the cell permeability and free radical- and ROS- scavenging activities of antioxidants are major factors affecting the protection of cell membranes against the oxidative damage induced by photosensitization reaction.

• The Korean Journal of Pharmacology
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• 제29권1호
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• pp.131-137
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• 1993

Human neutrophil elastase (HNE, EC 3,4,21, 11), a mediator of tissue breakdown, was inhibited by tetracycline, oxytetracycline and demeclocycline. Among them, oxytetracycline showed the most potent inhibitory effect on the activity of HNE. IC50 of this drug at our specific condition was less than 1 mM. Tetracycline inhibited human neutrophil elastase non-competitively, and oxytetracycline inhibited competitively. Ki values of tetracycline and oxytetracycline were 4.9 mM and 0.39 mM, respectively. Structural modified tetracycline, de-dimethylaminotetracycline, which showed no antibiotic activity since the active dimethylamino radical was removed from the position #4 of the tetracycline, showed similar inhibition effect on the activity of human neutrophil elastase to that of tetracycline. Thus, we speculated that inhibition of human neutrophil elastase by tetracyclines was not depended on the dimethylamino radical which is a critical active site for antibiotic effect, rather it was depended on the hydoxyl radical of tetracyclines. Therefore, the property of inhibiting elastase may be an additional molecular biochemical mechanism of action of these drugs at the inflammatory sites.

• The Korean Journal of Pharmacology
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• 제27권2호
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• pp.155-166
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• 1991

In order to evaluate a potential role of mitochondria in the mediation of toxicity of paraquat (PQ), submitochondrial particle and microsome of mouse liver were compared by oxygen radical generation and lipid peroxidation. With NADH in submitochondrial particle and NADPH in microsome as electron donors, PQ stimulated production of superoxide anion and $H_2O_2$ in both fractions. Under the same conditions, PQ enhanced the generation of ethylene from methional suggestiong stimulation of OH production by PQ. But these effects by PQ were somewhat lower in submitochondrial particle than in microsome. In addition, lipid peroxidation(measured as MDA production) was stimulated by PQ in both fractions. The stimulation of lipid peroxidation in both fractions seemed to occur by the same mechanism probably through perferryl ion. This was supported by the following findings: i) The lipid peroxidation in both fractions was partially inhibited by SOD and completely inhibited by DETAPAC(an iron chelator) but not by catalase or OH scavenger. ii) Addition of $ADP-Fe^{3+}$ further increased PQ-induced lipid peroxidation but decreased ethylene production from methional suggesting no correlation between OH production and lipid peroxidation. The redox-cycling of PQ in mitochondria appeared to be linked to NADH dehydrogenase, not to CoQ since all of the observed stimulations by PQ in submitochondrial particle were inhibited by p-hydroxymercuribenzoate(a NADH dehydrogenase inhibitor) but not affected by other respiratory chain blockers. The above results demonstrate that redox-cycling properties of PQ leading to oxygen radical generation and lipid peroxidation can also occur in mitochondria in the same manner as in microsome. Therefore, the observed actions of PQ in mitochondria suggest that mitochondria may also contribute to toxicity of this drug in vivo.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.363-363
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• 2008

The development of dry etching process for sapphire wafer with plasma has been key issues for the opto-electric devices. The challenges are increasing control and obtaining low plasma induced-damage because an unwanted scattering of radiation is caused by the spatial disorder of pattern and variation of surface roughness. The plasma-induced damages during plasma etching process can be classified as impurity contamination of residual etch products or bonding disruption in lattice due to charged particle bombardment. Therefor, fine pattern technology with low damaged etching process and high etch rate are urgently needed. Until now, there are a lot of reports on the etching of sapphire wafer with using $Cl_2$/Ar, $BCl_3$/Ar, HBr/Ar and so on [1]. However, the etch behavior of sapphire wafer have investigated with variation of only one parameter while other parameters are fixed. In this study, we investigated the effect of pressure and other parameters on the etch rate and the selectivity. We selected $BCl_3$ as an etch ant because $BCl_3$ plasmas are widely used in etching process of oxide materials. In plasma, the $BCl_3$ molecule can be dissociated into B radical, $B^+$ ion, Cl radical and $Cl^+$ ion. However, the $BCl_3$ molecule can be dissociated into B radical or $B^+$ ion easier than Cl radical or $Cl^+$ ion. First, we evaluated the etch behaviors of sapphire wafer in $BCl_3$/additive gases (Ar, $N_2,Cl_2$) gases. The behavior of etch rate of sapphire substrate was monitored as a function of additive gas ratio to $BCl_3$ based plasma, total flow rate, r.f. power, d.c. bias under different pressures of 5 mTorr, 10 mTorr, 20 mTorr and 30 mTorr. The etch rates of sapphire wafer, $SiO_2$ and PR were measured with using alpha step surface profiler. In order to understand the changes of radicals, volume density of Cl, B radical and BCl molecule were investigated with optical emission spectroscopy (OES). The chemical states of $Al_2O_3$ thin films were studied with energy dispersive X-ray (EDX) and depth profile anlysis of auger electron spectroscopy (AES). The enhancement of sapphire substrate can be explained by the reactive ion etching mechanism with the competition of the formation of volatile $AlCl_3$, $Al_2Cl_6$ or $BOCl_3$ and the sputter effect by energetic ions.