• Anxiety and mood
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• v.11 no.1
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• pp.33-37
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• 2015

Objective : Impaired response inhibition has been suggested to play an important role in the pathophysiology of obsessive-compulsive disorder (OCD). The aim of this study was to evaluate the response inhibition in patients with OCD, by using the Go/NoGo paradigm, and to better understand its associations with clinical symptoms. Methods : The participants included 63 OCD patients and 80 healthy volunteers matched in age and sex. response inhibition was evaluated using computerized Go/NoGo task, in which their commission error rates, omission error rates, and mean response times were measured. The severity of clinical symptoms in the OCD patients was assessed using Montgomery-Asberg Depression Scale and Yale-Brown Obsessive Compulsive Scale. Result : OCD patients showed significantly impaired inhibition and higher omission errors rates despite their slower response time, compared to normal controls. Clinical symptoms were not correlated with commission errors and omission errors. Conclusion : The present results indicate that impairment in response inhibition may play a critical role in the pathophysiology of OCD as a trait. These findings suggest that deficit of response inhibition may contribute to developing and maintaining clinical symptoms such as compelling need to repeat certain actions in patients with OCD.

• The Journal of Korean Medicine
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• v.26 no.1 s.61
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• pp.26-36
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• 2005

Objective : Many traditional herbal remedies exhibit several beneficial effects including anti-inflammation. Euonymus alatus (Thunb.) Sieb (EA), known as Gui jun woo in Korea, has long been used in folk medicine to regulate Qi (bodily energy) and blood circulation, relieve pain, eliminate stagnant blood, and treat dysmenorrhea in oriental countries. The exact mechanism of the anti-inflammatory action of Euonymus alatus (Thunb.) Sieb (EA), however, has not been determined. Methods: Since there is increasing evidence that nitric oxide (NO) plays a crucial role in the pathogenesis of inflammatory diseases, this study was undertaken to address whether the methanol (MeOH) extract and its fractions of the bark of EA could modulate the expression of inducible NO synthase (iNOS) in thioglycollate-elicited murine peritoneal macrophages and murine macrophage cell line, RA W264.7 cells. Results: Stimulation of the peritoneal macrophages and RAW264.7 cells with $interferon-\gamma\;(IFN-\gamma)$ and lipopolysaccharide (LPS) resulted in increased production of NO in the medium. However, the butanol (BuOH) fraction of the MeOH extract of EA barks showed marked inhibition of NO synthesis in a dose-dependent manner. The inhibition of NO synthesis was reflected in the decreased amount of iNOS protein, as determined by Western blotting. The BuOH fraction did not affect the viability of RA W264.7 cells, as assessed by methylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT) assay; rather, it reduced endogenous NO-induced apoptotic cell death via inhibition of NO synthesis in RAW264.7 cells. On the other hand, the MeOH and BuOH fraction showed no inhibitory effect on the synthesis of NO by RAW264.7 cells, when iNOS was already expressed by the stimulation with $IFN-\gamma$ and LPS. Conclusion: Collectively, these results demonstrate that the MeOH and BuOH fraction inhibits NO synthesis by inhibition of the induction of iNOS in murine macrophages.

• The Journal of Internal Korean Medicine
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• v.30 no.2
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• pp.288-297
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• 2009

Objective : Inflammatory cytokines have a close relationship to insulin dependent diabetes mellitus (IDDM). The inhibitory effect of Smilacis Glabrae Rhizoma (SGR) were examined on production of nitric oxide (NO), prostaglandin $E_2$ $(PGE_2)$, synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and NF-${\kappa}$B activation in Raw 264.7 cells. Methods: Raw 264.7 cells were pretreated with SGR(20, 50, 100 ${\mu}g$/ml), and then cultured with lipopolysaccharides (LPS). Cell viability was measured by MTT assay; inhibition of NO, $PGE_2$, and TNF-${\alpha}$ production were measured by Griess reagent and enzyme-linked immunosorbent assay(ELISA). Induction of COX-2 and iNOS were determined by western blotting analysis. Inhibition of NF-${\kappa}$B was measured by immunofluorescence assay (IFA). Results: SGR inactivated NF-${\kappa}$B, and inhibited the production of NO, iNOS, and $PGE_2$. Inhibition of COX-2 and TNF-${\alpha}$ could not be confirmed. Conclusions: From the above result. SGR was found to have an anti-inflammatory effect of inhibition of NO, iNOS, and $PGE_2$ production via inhibition of NF-${\kappa}$B.

• Environmental Engineering Research
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• v.13 no.3
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• pp.125-130
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• 2008

Free ammonia ($NH_3$-N) inhibition of nitrite-oxidizing bacteria (NOB) has been widely studied for partial nitrification (or nitrite accumulation) and denitrification via nitrite ($NO_2^-$-N) as a low-cost treatment of ammonium containing wastewater. The literature on $NH_3$-N inhibition of NOB, however, shows disagreement about the threshold $NH_3$-N concentration and its degree of inhibition. In order to clarify the confusion, a simple and cheap respirometric method was devised to investigate the effect of free ammonia inhibition of NOB. Sludge samples from an autotrophic nitrifying reactor were exposed to various $NH_3$-N concentrations to measure the maximum specific nitrite oxidation rate ($\hat{K}_{NO}$) using a respirometer. NOB biomass was estimated from the yield values in the literature. Free ammonia inhibition of nitrite oxidizing bacteria was reversible and the specific nitrite oxidation rate ($K_{NO}$) decreased from 0.141 to 0.116, 0.100, 0.097 and 0.081 mg $NO_2^-$-N/mg NOB h, respectively, as the $NH_3$-N concentration increased from 0.0 to 1.0, 4.1, 9.7 and 22.9 mg/L. A nonlinear regression based on the noncompetitive inhibition mode gave an estimate of the Inhibition concentration ($K_I$) of free ammonia to be 21.3 mg $NH_3$-N/L. Previous studies gave $\hat{K}_{NO}$ of Nitrobacter and Nitrospira as 0.120 and 0.032 mg/mg VSS h. The free ammonia concentration which inhibits Nitrobacter was $30{\sim}50\;mg$ $NH_3$-N/L and Nitrospira was inhibited at $0.04{\sim}0.08\;mg$ $NH_3$-N/L. The results support the fact that Nitrobacter is the dominant NOB in the reactor. The variations in the reported values of free ammonia inhibition may be due to the different species of nitrite oxidizers present in the reactors. The respirometric method provides rapid and reliable analysis of the behavior and community of the nitrite oxidizing bacteria.

• Geosystem Engineering
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• v.21 no.5
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• pp.243-250
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• 2018

This study investigated nitrite ($NO_2{^-}$) accumulation due to FA (Free Ammonia: $NH_3$) inhibition in an anaerobic-aerobic-anoxic (AOA) process reactor to mainly treat wastewater containing 302-610 mg/L of $NH_3/NH_4{^+}-N$. Based on an experimental operation focusing on the nitrification, it was observed that $NO_2{^-}$ was accumulated in the aerobic nitrification zone as pH increased, due to inhibition of $NO_2{^-}$ conversion to $NO_3{^-}$ by FA. This result implied FA inhibition to NOB ($NO_2{^-}$-Oxidizing Bacteria) for converting $NO_2{^-}$ to $NO_3{^-}$. The objective of this study is to develop a feasible monitoring procedure for early detection of the FA inhibition toward $NO_2{^-}$ accumulation and poor nitrification. Thus, in order to rapidly assess FA concentrations, an $NH_3$ probe was utilized to measure $NH_3$ concentrations together with applying a simple model prediction using the measured $NH_4{^+}$ concentrations, the Henry's law constant of $NH_3$ and measured pH. The predictive model $NH_3$ levels were verified by a good correlation (89%) with the corresponding measured data, but the model prediction underestimated FA concentrations at less than 7.4 and a little overestimated at pH above 7.5. Interestingly, accumulated $NO_2{^-}$ levels were roughly correlated with FA levels that were observed at delayed time points. This reflects the detected FA levels can be good indicators of $NO_2{^-}$ levels with some delayed time. $NO_2{^-}$ accumulation started at measured FA concentrations of higher than approximately 3 mg/L and ceased below that FA level.

• Natural Product Sciences
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• v.22 no.3
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• pp.193-200
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• 2016

This study describes the anti-inflammatory, anti-oxidant, and melanogenesis inhibition activities of methanol extract and various organic solvent fractions of Arecae Pericarpium. We examined the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells, 1,1-diphenyl-2-picrylhydrazine (DPPH) scavenging activity, mushroom tyrosinase inhibition activity and melanin contents. The study showed that, among all tested fractions, methylene chloride fraction showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells ($IC_{50}$ value $8.89{\mu}g/mL$) and DPPH radical scavenging activity ($EC_{50}$ value $21.39{\mu}g/mL$). Methylene chloride and ethyl acetate fractions similarly inhibited mushroom tyrosinase activity. Methanol extract exhibited strongest reduction of melanin content in B16F10 melanoma cells. Based on the bioactivity assay results, methylene chloride and ethyl acetate fractions were further separated. Eight phenolic compounds were isolated, which are dimeric syringol (1), catechol (2), 4-hydroxybenzaldehyde (3), vanillin (4), 4-hydroxyacetophenone (5), apocynin (6), protocatechuic acid (7) and 4-hydroxybenzoic acid (8). Among the isolated compounds tested, catechol showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells. Catechol also showed the concentration-dependent NF-${\kappa}B$ inhibition activity. Arecae Pericarpium might have potentials to be developed as anti-inflammatory agent or dermatological product for skin-whitening agent.

• Journal of Gifted/Talented Education
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• v.25 no.4
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• pp.469-491
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• 2015

The present study investigated the inhibition mechanisms of gifted children, which is one of the main executive functions in human cognitive system. The inhibition process was subdivided into cognitive and emotion aspects in order to examine the interplay between these two aspects with respect to inhibition processing. In Experiment 1, word-color Stroop task was used to study the cognitive inhibition process of 100 gifted children(Gender: 62 males, 38 females; Academic grade: 46 Elementary school students, 54 Secondary school students). In addition, emotional Stroop task was utilized in Experiment 2 to examine the effect of emotional component during cognitive inhibition process. Results revealed a significant cognitive cost (i.e., word-color Stroop effect) when participants had to withhold automatic response during cognitive inhibition task in Experiment 1. Such cognitive cost was reduced as the chronological age of the participants increased, with no difference in gender. The results in Experiment 2 showed no significant emotional inhibition cost (i.e., emotional Stroop effect) during cognitive inhibition task, and there was no effect of gender nor age. This suggests that the emotional component conveyed in words did not lead to cognitive bias effects. This study proposes that the cognitive and emotional inhibition processes are seemingly independent mechanisms that engage in complex interactions during inhibition processing of behavioral response.

• Korean Journal of Cognitive Science
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• v.14 no.4
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• pp.1-7
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• 2003

The common features of the behavioral inhibition and the action monitoring that are considered as one of the executive functions were investigated using event-related brain potentials (ERPs) and source localization analysis. The electrophysiological correlates of behavioral inhibition and action monitoring ate analyzed when the subjects performed the Go/NoGo task. Two ERP components of behavioral inhibition termed as N200 and P300 in NoGo condition were differ from those of Go condition, that is the amplitudes of NoGo N200 and P300 are largest on the fronto-central region, which may reflect the inhibitory control of frontal lobe required in NoGo condition. The error-related negativity (ERN) observed on the fronto-central region when the subjects committed error was much larger in amplitude and faster in latency than those of the correct-related negativity (CRN), which may indicate that the signal of action monitoring is much more required for the error response. The correlation analysis for the ERP components of behavioral inhibition and action monitoring revealed the significant negative correlation among the latencies of NoGo N200 and P300 and the amplitude of ERN, which may reflects that the faster subjects inhibit response, the more monitor their own action. The close relationship between behavioral inhibition and action monitoring was also supported by the results of source localization analysis, which showed the common neural sources of NoGo N200 and ERN was anterior cingulate cortex.

• YAKHAK HOEJI
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• v.50 no.6
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• pp.367-371
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• 2006

Phellinus pini (Hymenocaetaceae) has been used for the immunomodulating activity hypolipidemic effect, gastric cancer non-insulin dependant diabetes, diarrhea, and menstrual irregularity. From the screening of each fraction for the inhibitory activity of NO production in lipopolysaccaride (LPS) activated RAW 264.7 cells, methanol extract of Phellinus pini and hexane soluble fraction exhibited inhibition of NO production compared with LPS control without toxicity. The hexane soluble fraction showed dose dependent inhibition of NO production. According to activity guided fractionation, the active hexane fr. was repeatedly chromatographed over silica gel, ergosta-4,6,8(14),22- tetraen-3-one was isolated. The compound inhibited NOS activation (IC$_{50}$ = 29.7 uM) and NO production of activated macrophage at 30 uM.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.338-345
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• 2004

Scavenging effects of DPPH radical and hydroxyl radical, inhibition of linoleic acid oxidation, inhibition of NO synthesis and iNOS expression were tested with extracts and chromatographic subfractions of Canavalia lineata obtained at Jeju island. Chloroform extract and its subfractions gave moderate effects on scavenging DPPH radical and hydroxyl radical, They also inhibited linoleic acid oxidation, and NO synthesis. Inhibition of NO synthesis resulted from the repression of iNOS gene expression. Ethyl acetate extract and its subfractions showed excellent effects on scavenging DPPH radical and hydroxyl radical, while they were cytotoxic.