• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.461-467
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• 2009

The auditory cortex (A1) encodes the acquired significance of sound for the perception and interpretation of sound. Nitric oxide (NO) is a gas molecule with free radical properties that functions as a transmitter molecule and can alter neural activity without direct synaptic connections. We used whole-cell recordings under voltage clamp to investigate the effect of NO on spontaneous GABAergic synaptic transmission in mechanically isolated rat auditory cortical neurons preserving functional presynaptic nerve terminals. GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs) in the A1 were completely blocked by bicuculline. The NO donor, S-nitroso-N-acetylpenicillamine (SNAP), reduced the GABAergic sIPSC frequency without affecting the mean current amplitude. The SNAP-induced inhibition of sIPSC frequency was mimicked by 8-bromoguanosine cyclic 3',5'-monophosphate, a membrane permeable cyclic-GMP analogue, and blocked by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, a specific NO scavenger. Blockade of presynaptic $K^+$ channels by 4-aminopyridine, a $K^+$ channel blocker, increased the frequencies of GABAergic sIPSCs, but did not affect the inhibitory effects of SNAP. However, blocking of presynaptic $Ca^{2+}$ channels by $Cd^{2+}$, a general voltage-dependent $Ca^{2+}$ channel blocker, decreased the frequencies of GABAergic sIPSCs, and blocked SNAP-induced reduction of sIPSC frequency. These findings suggest that NO inhibits spontaneous GABA release by activation of cGMP-dependent signaling and inhibition of presynaptic $Ca^{2+}$ channels in the presynaptic nerve terminals of A1 neurons.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.123-128
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• 2011

Caesalpinia sappan (C. sappan) is a medicinal plant used for promoting blood circulation and removing stasis. During a screening procedure on medicinal plants, the ethylacetate extract of the lignum of C. sappan (CLE) showed inhibitory activity on arginase which has recently been reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. CLE inhibited arginase II activity prepared from kidney lysate in a dose-dependent manner. In HUVECs, inhibition of arginase activity by CLE reciprocally increased NOx production through enhancement of eNOS dimer stability without any significant changes in the protein levels of eNOS and arginase II expression. Furthermore, CLE-dependent arginase inhibition resulted in increase of NO generation and decrease of superoxide production on endothelium of isolated mice aorta. These results indicate that CLE augments NO production on endothelium through inhibition of arginase activity, and may imply their usefulness for the treatment of cardiovascular diseases associated with endothelial dysfunction.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.235-239
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• 2017

The objective of the present study was to evaluate in vitro antioxidant activity, antioxidant content and pancreatic lipase inhibitory activities of Makgeolli supplemented with 0, 1, 2, and 4% (w/v) Jeju camellia mistletoe during fermentation. Total phenolic and flavonoid contents tended to increase as content of Jeju camellia mistletoe increased. Supplementation with Jeju camellia mistletoe resulted in a significant increase in the scavenging capacities of 1,1-diphenyl-2-picrylhydrazyl, hydrogen peroxide, nitric oxide and superoxide anion radicals, and reducing power activity. Moreover, pancreatic lipase inhibitory activity was significantly elevated by Jeju camellia mistletoe addition. These results suggest that Jeju camellia mistletoe is considered to be a good material to improve antioxidant and pancreatic lipase inhibitory activities of makgeolli.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.336-344
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• 2017

The anti-inflammatory effects of cell-free extracts from wild yeasts, Meyerozyma guilliermondii YJ34-2 and Rhodotorula graminis YJ36-1, caused by the inhibition of nitric oxide (NO) activity and cytotoxic effects were determined. Cell-free extracts from these two yeast strains had dose-dependent inhibitory effects on the production of lipopolysaccharide-induced NO and there were no cytotoxic effects on the treated cells or negative effects on their proliferation. Their cell-free extracts were also shown to have inhibitory effects on pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$ and $prostaglandin-E_2$, in a dose-dependent manner. Maximal inhibitory activity on NO production occurred in cell-free extracts of Meyerozyma guilliermondii YJ34-2 cultivated at $30^{\circ}C$ for 24 hr and Rhodotorula graminis YJ36-1 cultivated at $25^{\circ}C$ for 24 hr in the yeast extract-peptone-dextrose (YPD) media.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1386-1391
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• 2017

The bioactivities of boxthron fruits, a source of oriental medicine, are well known, whereas phytochemical studies of the boxthorn stem are rare. In this study, the stem extract of boxthorn (Lycium chinense Miller) and its subfractions were evaluated for their effects on nitric oxide (NO) inhibition and procollagen type I peptide (PIP) synthesis. A phenolic amide isolated from the stem extract was also assayed for these effects. The compound, N-trans-feruloyltyramine, was identified by $^1H$, $^{13}C$, and 2D-nuclear magnetic resonance analyses. In NO inhibition, the chloroform fraction (CF) exhibited the strongest inhibitory activity ($MIC_{50}=24.69{\mu}g/ml$) among the subfractions of the ethanol extract (EE). N-trans-feruloyltyramine isolated from the CF showed strong NO inhibitory activity, presenting with an $MIC_{50}$ of $31.36{\mu}g/ml$. The EE, CF, and N-trans-feruloyltyramine shown to have NO inhibition activity were assayed for the activity of PIP synthesis. The EE and CF showed relatively high PIP values of 38.8% and 24.21% at $100{\mu}g/ml$, respectively. The PIP value for $20{\mu}g/ml$ N-trans-feruloyltyramine showed a 36% increase compared with the non-treated control, whereas that treated with $20{\mu}g/ml$ ascorbic acid as a positive control showed a 13% increase. The results suggest that the proper stem extract of boxthorn stem could be efficiently used to produce good cosmetic effects.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.143-149
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• 2009

The aim of this study was to elucidate the anti-inflammatory activity of safflower (Carthamus tinctorius L.) ethanolic extract fractions (CFEFs). Butanol fraction had the strongest antioxidant activity, and all CFEFs, except for chloroform fraction, partly inhibited lipopolysaccharide (LPS)-induced nitrite production in RAW 264.7 cells. In the cell-free system, hexane and butanol fractions chemically quenched nitric oxide (NO). In addition, the iNOS mRNA transcription was suppressed by ethanol extract and hexane fraction in LPS-stimulated RAW 264.7 cells. Taken together, the inhibitory effect of CFEFs on NO production from LPS-stimulated RAW 264.7 cells, might be due to both the chemical NO quenching activity and the suppression of iNOS mRNA transcription partially. The synthesis of prostaglandin $E_2$ ($PGE_2$) was potently inhibited by ethanol extract to below basal label, and the transcription of cyclooxygenase-2 (COX-2), an enzyme involving in $PGE_2$ synthesis, was partially suppressed by ethanol extract and hexane fraction. Based on these results, CFEFs may be useful as an alternative medicine for the relief and retardation of immunological inflammatory responses through the reduction of inflammatory mediators, including NO and $PGE_2$ production.

• YAKHAK HOEJI
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• v.51 no.6
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• pp.430-434
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• 2007

The anti-inflammatory activity of fruit body of Phellinus pini was investigated by activity-guided fractionation. From the screening of each fraction for the inhibitory activity of NO production in lipopolysaccaride (LPS) activated RAW 264.7 cells, methanol extract and its hexane soluble fraction of Phellinus pini exhibited inhibition of NO production compared with LPS control without toxicity. The hexane soluble fraction showed dose-dependent inhibition of NO production. The active hexane fraction was repeatedly chromatographed over silica gel, ergosta-7,24(28)-dien-3-ol(1) and ergosterol peroxide (2) were isolated and identified. Ergosterol derivatives were inhibited NOS activation, $IC_{50}$ of them were $18.9{\pm}3.9{\mu}M$ (1) and $20.4{\pm}4.5{\mu}M$ (2).

• Archives of Pharmacal Research
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• v.27 no.7
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• pp.751-756
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• 2004

Flavonoids have been demonstrated to exhibit a wide range of biological activities including anti-inflammatory and neuroprotective actions. Although a significant amount of flavonoids has been identified to be present as glycosides in medicinal plants, determinations of the biological activities of flavonoids were mainly carried out with aglycones of flavonoids. Therefore, the exact role of the glycosidation of flavonoid aglycones needs to be established. In an attempt to understand the possible role of glycosidation on the modulation of the biological activities of flavonoids, diverse glycosides of kaempferol, quercetin, and aromadendrin were examined in terms of their anti-inflammatory activity determined with the suppression of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV2 microglial cells. The results indicated that glycosidation of aglycones attenuated the suppressive activity of aglycones on LPS-induced NO production. Although attenuated, some of glycosides, depending on the position and degree of glycosidation, maintained the inhibitory capability of LPS-induced NO production. These findings suggest that glycosidation of flavonoid aglycones should be considered as an important modulator of the biological activities of flavonoids.

• Natural Product Sciences
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• v.17 no.3
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• pp.175-180
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• 2011

Eleven compounds were isolated from fresh leaves of Abies koreana (Pinaceae), and structures of these compounds were determined to be 3-hydroxy-2-methyl-4-pyrone (1), maltol-3-O-${\beta}$-D-glucoside (2), (-)-epicatechin (3), naringenin 7-O-${\beta}$-D-glucopyranoside (4), naringenin-7-O-rhamnoglucoside (5), kaempferol 3-O-${\beta}$-D-glucopyranoside (6), (+)-isolariciresinol (7), secoisolariciresinol (8), rhododendrol (9), ferulic acid (10) and 4-(4-hydroxyphenyl)butan-2-one (rheosmin) (11) by comparing $^1H$-, $^{13}C$-NMR and MS spectroscopic data with reference values. Compounds 3, 5, 7, 8, 9, 10, 11 were isolated for the first time from A. koreana. Among eleven isolates, compounds 1, 7 and 11 showed inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 microglia in a concentration dependent manner.

• Animal cells and systems
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• v.5 no.1
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• pp.59-64
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• 2001

To understand the late gut development and differentiation, identification and characterization of target genes of homeotic genes involved in gut development are required. We have previously reported that homeodomain proteins can regulate expression of the cell proliferation-related genes. We investigated here the expression of the Drosophila proliferating cell nuclear antigen(PCNA) and E2F(dE2F) genes in larval and adult guts using transgenic flies bearing lacz reporter genes. Both PCNA and dE2F genes were expressed strongly in whole regions of the larval and adult guts including the esophagus, proventriculus, midgut and hindgut, showing higher expression in foregut and hindgut imaginal rings of larva. Nitric Oxide(NO) has been known to be involved in cell proliferation and tumor growth and also to have an antiproliferative activity. Therefore, we also investigated effects of NO on the expression of PCNA and dE2F genes in gut through analyses of lacz reporter expression level in the SNP (NO donor)-treated larval guts. Expressions of both PCNA and dE2F were greatly declined by SNP. The inhibitory effect of NO was shown in whole regions of the gut, especially in hindgut, while the internal region of proventriculus, esophagus, foregut imaginal ring and hindgut imaginal ring was resistant. Our results suggest that this inhibitory effect may be related with the antiproliferative activity of NO.