• BMB Reports
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• v.32 no.3
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• pp.226-231
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• 1999

In vitro effects of acetone on cytochrome P450 (P450)-dependent benzo(a)pyrene (B(a)P) hydroxylation supported by cumene hydroperoxide (CuOOH) or NADPH/$O_2 $ systems were studied using 3-methylcholanthrene-pretreated rat liver microsomes. The maximal rate of B(a)P hydroxylation at constant concentration ($80\;{\mu}M)$ of the substrate was observed in the presence of $30\;{\mu}M$ CuOOH. However, at concentrations higher than $30\;{\mu}M$ CuOOH the hydroxylation rates were rapidly decreased. In contrast to CuOOH, at a concentration of $200\;{\mu}M$ NADPH, B(a)P hydroxylation rate reached a plateau. At concentrations higher than $200\;{\mu}M$ NADPH, the rates of substrate hydroxylation were maintained at the maximal rate with no inhibition. Acetone at 1% (v/v) enhanced both CuOOH- and NADPH/$O_2$-supported B(a)P hydroxylation at the optimal concentrations of the cofactors. At concentrations higher than 1% (v/v) acetone, substrate hydroxylation was sterero specific under the support of these two cofactors; it was strongly enhanced with $30\;{\mu}M$ CuOOH, but rather inhibited in the $200\;{\mu}M$> NADPH/$0_2 $ system. The lipid peroxidation rate induced during CuOOH-supported P450-dependent B(a)P hydroxylation was increased as CuOOH concentrations were increased. Acetone in the concentration range of 2.5~7.5%(v/v) inhibited lipid peroxidation during CuOOH supported B(a)P hydroxylation. The finding that CuOOH-supported B(a)P hydroxylation is greatly enhanced by acetone suggests that acetone may contribute more to the activation of oxygen (for the insertion of oxygen into the substrate) in the presence of CuOOH than with NADPH/$O_2$. Acetone may also contribute to the partial inhibition of destruction of microsomal membranes by lipid peroxidation.

• Biomolecules & Therapeutics
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• v.23 no.2
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• pp.201-206
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• 2015

Scutellaria baicalensis is one of the most widely used herbal medicines in East Asia. Because baicalein and baicalin are major components of this herb, it is important to understand the effects of these compounds on drug metabolizing enzymes, such as cytochrome P450 (CYP), for evaluating herb-drug interaction. The effects of baicalin and baicalein on activities of ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), benzyloxyresorufin O-debenzylase (BROD), p-nitrophenol hydroxylase and erythromycin N-demethylase were assessed in rat liver microsomes in the present study. In addition, the pharmacokinetics of caffeine and its three metabolites (i.e., paraxanthine, theobromine and theophylline) in baicalin-treated rats were compared with untreated control. As results, EROD, MROD and BROD activities were inhibited by both baicalin and baicalein. However, there were no significant differences in the pharmacokinetic parameters of oral caffeine and its three metabolites between control and baicalin-treated rats. When the plasma concentration of baicalin was determined, the maximum concentration of baicalin was below the estimated $IC_{50}$ values observed in vitro. In conclusion, baicalin had no effects on the pharmacokinetics of caffeine and its metabolites in vivo, following single oral administration in rats.

• The Korean Journal of Mycology
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• v.29 no.1
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• pp.67-71
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• 2001

A steroid compound, F-l with antioxidative activity from the fruit bodies of Fomitella fraxinea was isolated by ethyl acetate extraction, silica gel column chromatography, and preparative silica thin layer chromatography. The structure of the compound was determined to be crgosta-7,22-diene-3-one-$16{\beta}-ol$ by IR, NMR, and GC-Mass. The compound exhibited inhibition on lipid peroxidation of rat liver microsomes, with $IC_{50}$ value of $3.8{\mu}g/ml$.

• KSBB Journal
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• v.15 no.2
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• pp.150-155
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• 2000

Antioxidative activity of c비ture of Streptomyces sp. BH-405 was investigated. After removal of pellets of Streptomyces sp. B BH-405, antioxidative substances were is미ated and suc$\infty$sively purified from culture of Streptomyces sp. BH-405 by by thin | layer chromatography $\pi$LC) or silica gel column chromatography. The fraction 3 obtained from ethylether fractionation of the C culture appeared highest level of anti oxidative activity as determined by thiocyanate method. Band 2 obtained by further P purification of this fraction showed higher anti oxidation level than that of same concentration of dl- $\alpha$ -tocopherol, butylated h hydroxy anisole (BHA). The band 2 showed higher rate of 1, 1.diphenyl 2-picrylhydrazyl (DPPH) decolorization than dl-$\alpha$-tocopherol. In the rat liver microsomes, band 2 rapidly inhibited lipid peroxidation which was initiated enzymatically by r reduced nicotinamide adenine dinucleotide phosphate (NADPH) or non-enzymatically by Fenton’s reagent. Band 2 inhibited on | lipid peroxidation of mitochondria or the linoleic acid hydro peroxide induced peroxidation system. It is concluded that band 2 obtained by fractionation of Streptomyces sp. BH-405 cultivation contained antioxidants with the capacity to inhibit oxidative m modification.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.539-549
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• 2019

Background: 20(S)-Protopanaxadiol (PPD), the aglycone part of 20(S)-protopanaxadiol ginsenosides, possesses antidepressant activity among many other pharmacological activities. It is currently undergoing clinical trial in China as an antidepressant. Methods: In this study, an ultra-performance liquid chromatography coupled with triple quadrupole time-of-flight mass tandem mass spectrometry method was established to identify the metabolites of PPD in human plasma and urine following oral administration in phase IIa clinical trial. Results: A total of 40 metabolites in human plasma and urine were identified using this method. Four metabolites identified were isolated from rat feces, and two of them were analyzed by NMR to elucidate the exact structures. The structures of isolated compounds were confirmed as (20S,24S)-epoxydammarane-12,23,25-triol-3-one and (20S,24S)-epoxydammarane-3,12,23,25-tetrol. Both compounds were found as metabolites in human for the first time. Upon comparing our findings with the findings of the in vitro study of PPD metabolism in human liver microsomes and human hepatocytes, metabolites with m/z 475.3783 and phase II metabolites were not found in our study whereas metabolites with m/z 505.3530, 523.3641, and 525.3788 were exclusively detected in our experiments. Conclusion: The metabolites identified using ultra-performance liquid chromatography coupled with triple quadrupole time-of-flight mass spectrometry in our study were mostly hydroxylated metabolites. This indicated that PPD was metabolized in human body mainly through phase I hepatic metabolism. The main metabolites are in 20,24-oxide form with multiple hydroxylation sites. Finally, the metabolic pathways of PPD in vivo (human) were proposed based on structural analysis.

• BMB Reports
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• v.32 no.3
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• pp.232-238
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• 1999

Sex differences in the induction of microsomal cytochrome P-450 (CYP) and the activities of several related enzymes of Sprague-Dawley rats treated with 1-bromopropane (1-BrP) were investigated. Male and female rats were exposed to 50, 300, and 1800 ppm of 1-BrP per kg body weight (6 h a day,S days a week, 8 weeks) by inhalation. The mean body weight of 1-BrP treated groups increased according to the day elapsed, but four and five weeks respectively after the start of the exposure, the mean body weight of male and female rats had significantly reduced in the group treated with 1800 ppm 1-BrP compared with the control group (p<0.01). While the relative weights of liver increased in both sexes, statistical significance in both sexes was found only in the group receiving 1800 ppm/kg of 1-BrP (p<0.01). The total contents of CYP, $b_5$, NADPH-P-450 reductase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), and p-nitrophenol hydroxylase (pNPH) activities were examined for the possible effects of 1-BrP. No significant changes in the CYP and $b_5$ contents, NADPH-P-450 reuctase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), and pentoxyresorufin- O-dealkylase (PROD) were observed between the control and treated groups. The activity of pNPH increased steadily with the increase in the concentration of 1-BrP in both sexes, but was significantly increased only in the 1800 ppm-treated group of male rats (p<0.05). When Western blottings were carried out with three monoclonal antibodies (MAb 1-7-1, MAb 2-66-3, and MAb 1-98-1) which were specific against CYP1A1/2, CYP2B1/2, and CYP2E1, respectively, a strong signal corresponding to CYP2E1 was observed in microsomes obtained from rats treated with 1-BrP. Glutathione S-transferase (GST) activity and the content of lipid peroxide significantly increased in the treated groups compared with the control group (p<0.05). These results suggest that 1-BrP can primarily induce CYP2E1 as the major form and that GST phase II enzymes play important roles in 1-BrP metabolism, showing sex-dependence in the metabolic mechanism of 1-BrP in the rat liver.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.726-735
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• 2000

This study was conducted to investigate the biological activities of polysaccharide extracted from the fruit body and cultured mycelia of Phellinus linteus IY001. All fractions were extracted by hot water, in the next, Fr. I, Fr. II, Fr. III and Fr. IV were polysaccharide obtained by ethanol precipitation or ultrafiltration. The highest antitumor activity against sarcoma 180 in ICR mice was observed in Fr. III and Fr. IV at the level 85%, but the antitumor activity had no connection with their anticomplementary activity in vitro, it might probably be due to extraction of hot water. All fractions promoted the production of nitric oxide and $TNF-{\alpha}$ in macrophage, addition of Fr. I and Fr. II resulted in production of nitric oxide$3(5.9{\sim}37.6\;{\mu}M)$ and of the $TNF-{\alpha}$ production($8,696.2{\sim}9,420pg/ml)$. All fractions inhibited the lipid peroxidation induced by $AsA/Fe^{2+}$, $ADP/NADPH/Fe^{3+}\;and\;CCl_4/NADPH$ in rat liver microsomes, and Fr. III showed the electron donating ability stronger than tocopherol in assay system using DPPH. From these results, it is suggested that all fractions contain immunoregulatory components which may protect cellular materials from the oxidative damages by their radical scavenging activities.

• Korean Journal of Community Nutrition
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• v.2 no.5
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• pp.735-744
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• 1997

The effect of green tea drinking on the hepatocellular chemical cacinogenesis have been studied. Placental glutathione S-transferase(GST-P) positive foci area in a liver tissue, contents of thiobarbituric acid reactive substances(TBARS), total cytochrome P450 and glucose 6-phospphatase(G6P) activity in hepatic microsomes were investigated. Weaning Sprague-Dawley male rats were fed AIN-76A diet with deionized water or green tea infusion, Rats of CTR and CTR+ groups were provided deionized water while GTI and GTI+ groups were provided green tea instead of deionized water for the entire experimental period of 13weeks. Rats of GTP and GTP + groups had deionized water for the first 6 weeks and switched to green tea for the last 7weeks of the experimental period. CTR+, GTI +, and GTP + groups were carcinogen treated groups, Diethylnitrosamine(DEN) was injected as a single dose of 200mg/kg body weight intraperitoneally after 4 weeks of feeding. 2-Acetyla-minofluorene(AAF) was used as a carcinogen proliferater and suppled in the diets of carcinogen treated rats as 0.02% content for the last 6weeks starting from 2weeks after DEN injection. Rats were sacrificed after 13week weeks of feeding. The area and number of GST-P positive foci detected in carcinogen treated rats were decreased by green tea ingestion but when timing and duration of green tea ingestion was delayed after promotion period as in GTP + group, GST-P positive foci were not decreased as much as in GTI+ group. TBARS contents of carcinogen treated rats decreased by 13weeks of green tea ingestion but GTP groups did not show statiscally significant differences. G6P activities tended to decrease by carcinogen treatment but changes were not statiscally significant by green tea ingestion. Total cytochrome P450 contents were increased by carcinogen treatment. Thirteen weeks of green tea ingestion (GTI) also increased to total cytochrome P450 contents while 7weeks of green tea ingestion(GTP) did show any effects. These results suggest that green tea has suppressive effects on hepatocellular chemical carcinogenesis probably through the activities of antioxidant compounds. (Korean J Community utrition 2(5) : 735∼744, 1997)

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.88-94
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• 1999

Objectives. In order to gain a better understanding of the mechanism of DMF toxicity, recent studies have focused on hepatic drug metabolizing enzymes. In this study, we investigated the effects of DMF on the induction of P450 and the activities of other related enzymes in rat liver microsomes. Methods. DMF was administered to male Sprague Daweley rats by intraperitoneal injection at 0(control), 450(D1), 900(D2), 1,800(D3) mg DMF/kg body weight in olive oil once a day for three days. Hepatic P450 was measured by method of Omura and Sato. We evaluated selective assays for the three drug metabolizing cytochrome P450 isoenzymes 1A1, 2B1 and 2E1. Results. The content of microsomal protein, P450 and b5 were tended to be decreased in DMF treated group, but they were not statistically significant. The activity of NADPH-cytochrome P450 reductase was significantly increased dose dependently(p<0.01), but the activity of NADH-b5 reductase was decreased in the treated group(p<0.01). The activities of PROD and EROD were not significant between control and treated group. The activities of pNPH in the DMF treated groups were higher than that of the control group(p<0.01). When Western immunoblottings were carried out utilizing three monoclonal antibodies which were specific against P4501A1/1, P4502B1/2 and P4502E1, the strong density band corresponding to P4502E1 was observed with the microsomes obtained from the rats treated with DMF. But there were no significant increased in the P4501A1/2 and P4502B1/2 band densities in immunoblotting. Conclusions. These result suggested that P4502E1 was inducible by DMF and P4502E1 isozyme might be responsible for the hydroxylation of DMF to HMMF.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.819-825
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• 2005

The Antioxidative accvities of the cell free extracts containing high glutathione by Saccharomyces cerevisiae FF-8 were tested in vitro experimental models : DPPH method for radical scavenging activity, ferric TBA method and ferric thiocyanate method using linoleic acid and tissue microsome for lipid peroxidation inhibitions. The concentration of intercellular glutathione by cultivating S. cerevisiae FF-8 in the YM optimal medium obtained $204\mug/ml$, which was increased by 2.76-fold from $74\mug/ml$ in the YM basal medium. A comparition between the YM basal medium and the YM optimal medium on antioxidative substance produced by S. cerevisiae FF-8 was investigated. In DPPH ($\alpha, \alpha-diphenyl-\beta-picrylhydrazyl$) method, the electron donating activity of the glutathione produced by S. cerevisiae FF-8 cultured in the YM optimal medium was as high as that of BHT ($ 0.05\%w/v $). The antioxidative a.tivity was measured by inhibition against lipid peroxidation of rat tissues' microsomes. The results of anti-oxidant activity of the cell free extracts by S. rerevisiae FF-8 cultured in the YM optimal medium was shown in the following order . $ liver 60.98\% > kidney 56.43\% > heart 52.91\% > brain 52.13\% > testis 45.57\% > spleen 42.95\% $. In antioxidative activities determined by ferric thiocyanate method and TBA methods against lipid peroxidation, the lipid peroxidation in the control mixture increased more rapidly than the typical peroxidation curve of linoleic acid from one day. The antioxidative activity of the cell free extracts by cultivating S. cerevisine FF-8 in the YM optimal medium were higher than that of the YM basal medium. These data indicate that the cell free extracts containing a high intercellular glutathione of S. cerevisiae FF-8 cultured in YM optimal medium showed strong antioxidative capacities by DPPH radical scavenging activity and ferric thiocyanate and TBARS measurements.