• Journal of Life Science
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• v.23 no.9
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• pp.1126-1132
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• 2013

Cytochrome P450 2J2 (CYP2J2) is an enzyme mainly found in human extrahepatic tissues, with predominant expression in the cardiovascular system. CYP2J2 plays important roles in the metabolism of endogenous metabolites and therapeutic drugs, such as arachidonic acid, astemizole, ebastine, and terfenadine. CYP2J2 is also overexpressed in human cancer tissues and cancer cell lines and may represent a potential target for therapy of human cancers. In this study, 10 natural products obtained from plants and microorganisms were screened as potential CYP2J2 inhibitors. Among them, thelephoric acid showed strong inhibition of astemizole O-demethylation activity ($IC_{50}=3.23{\mu}M$) in a dose-dependent manner. Evaluation of the substrate dependency of the inhibitory activity of thelephoric acid showed that it strongly inhibited CYP2J2-mediated ebastine hydroxylation ($IC_{50}=5.32{\mu}M$) and terfenadine hydroxylation ($IC_{50}=3.27{\mu}M$) in a substrate nondependent manner. The present data suggest that this compound might be a potential candidate for further evaluation for anticancer activity.

• Journal of Life Science
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• v.21 no.11
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• pp.1558-1564
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• 2011

Cytochrome P450 2J2 (CYP2J2) plays important roles in the metabolism of endogenous metabolites such as arachidonic acid as well as therapeutic drugs. CYP2J2 is overexpressed in human cancer tissues and cancer cell lines, as well as in epoxyeicosatrienoic acids (EETs) and CYP2J2-mediated metabolites, and prevent apoptosis of cancer cells. This study aimed to screen marketed drugs for inhibitory potential on CYP2J2 isoforms using human liver microsomes. The initial screen isolated 4 compounds, from 120 marketed drugs, that inhibited the CYP2J2-mediated astemizole O-demethylation more than 50% in the following the order: haloperidol (75%) > terfenadine (56%) > aripiprazole (55%) > miconazole (52%). Miconazole strongly inhibited CYP2J2-mediated ebastine hydroxylation ($IC_{50}$=11.2 ${\mu}M$) and terfenadine hydroxylation ($IC_{50}$=2.2 ${\mu}M$), and terfenadine also inhibited CYP2J2-mediated ebastine hydroxylation ($IC_{50}$=13.6 ${\mu}M$) in a dose dependent manner. The present data suggest that these drugs are potential candidates for further evaluation for their anti-cancer 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)

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.831-837
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• 1999

Ochratoxin A (OA), a naturally occurring mycotoxin, has been known to cause renal and hepatic lesion in human and animals. This study was carried out to investigate the modulation effects of antioxidant vitamins on OA-induced lipid peroxidation associated with oxidative damage. Vitamin C (10 mg/kg/day) and vitamin E (63.8 mg/kg/day) were administered by intraperitoneal (i.p.) injection to male ICR mice, and 1 hr later, OA which was dissolved in 0.1 M $NaHCO_3$, treated 4 mg/kg/day by i.p. injection. During 4 days repeated, and then measured superoxide dismutase (SOD) activity, catalase activity and malondialdehyde (MDA) formation in microsomes of liver and kidney. Additionally, the relationship between cell damage and modulation effects of antioxidant vitamins was evaluated by comet assay. Results were as followed; i) SOD, catalase activity and MDA level were significantly increased by OA treated, ii) SOD, catalase activity and MDA formation were significantly decreased by antioxidant vitamins combine treated, iii) blood cell damage associated with lipid peroxidation, induced by OA, also modulated by antioxidant vitamins. These results indicated that antioxidant vitamins might be used for prevention of renal and hepatic damage due to ochratoxicosis.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.334-339
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• 2007

We evaluated the potential of 20 herbal medications (HMs), commonly used in Korea, to inhibit the catalytic activities of several cytochrome P450 (CYP) isoforms. The abilities of 500 ${\mu}g/ml$ of aqueous extracts of 20 HMs to inhibit phenacetin O-deethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), rosiglitazone hydroxylation (CYP2C8), tolbutamide 4-methylhydroxylation (CYP2C9), S-mephenytoin 4'-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and midazolam 1'-hydroxylation (CYP3A) were tested using human liver microsomes. The HMs Woohwangcheongsimwon suspension and Hwanglyeonhaedok-Tang strongly inhibited CYP2B6 and CYP2D6 isoform activity, respectively. These results suggest that some of the HMs used in Korea have potential to inhibit CYP isoforms in vitro. Although the plasma concentrations of the active constituents of the HMs were not determined, some herbs could cause clinically significant interactions because the usual doses of those individual herbs are several grams of freeze-dried extracts.