• Applied Biological Chemistry
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• v.38 no.2
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• pp.168-173
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• 1995

To investigate the effects of endosulfan on cytochrome P-450 enzymes in mouse(Balb c.), endosulfan was given by an intraperitoneal dose of 7.5 mg/kg. The treatment of endosulfan increased the cytochrome P-450 content by 3.3 to 4.2 fold, cytochrome $b_5$ content by 2.3 to 3.8 fold, NADPH cytochrome P-450 reductase activity by 5.3 to 6.4 fold and total haem content by 3.1 to 3.6 fold of mouse liver after 48 hrs of intraperitoneal injection. Endosulfan cytochrome P-450 absorption spectrum exhibited miximum at 387 nm and 389 nm and broad near 407 nm in the liver microsome. Reduced P-450-CO spectrum of the liver microsome exposed by the treatment of endosulfan showed maximum at 449 nm and 450 nm compared to that of the control having maximum at 451 nm, which indicated endosulfan induced cytochrome P-450 new isozymes. Aldrin epoxidase activities in the mouse liver and kidney were increased by 2.8 and 2.1 fold by the treatment of endosulfan. Also 7-ethoxyresorufin dealkylase activities in the mouse liver and kidney were elevated by 1.7 and 1.8 fold by treatment of endosulfan.

• YAKHAK HOEJI
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• v.34 no.2
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• pp.69-79
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• 1990

The aim of this experiment is to observe the toxicity of cypermethrin[S, R- -cyano-3-phenoxybenzyl-(1R, 1s, cis, trans)-2,2-dimethyl-3-(2,2-dichlorovinyl) cyclopropane carboxylate]and to investigate the synergistic effect of piperonyl butoxide on the cypermethrin toxicity. In cypermethrin (CYP) treated group, the biochemical parameters such as ALT, LDH, glucose in serum were remarkably elevated. The content of cytochrome P-450 and activity of NADPH-cytochrome c reductase in renal microsomal fraction were increased but those in hepatic microsomal fraction were not significantly increased. The activity of aniline hydroxylase and ATPase in liver were decreased. In the case of CYP plus piperonyl butoxide (PB) treated group, AST, ALT, LDH and glucose were more increased. Cytochrome P-450 and NADPH-cytochrome c reductase in liver and kidney were supressed and aniline hydroxylase and ATPase in liver were more decreased. Especially, in the case of CYP plus PB 100 mg/kg treated group, hepatic TBA value was increased but activity of glucose-6-phosphatase was remarkably depressed.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.141-146
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• 2012

Malassezia globosa is a common pathogenic fungus that causes skin diseases including dandruff and seborrheic dermatitis in humans. Analysis of its genome identified a gene (MGL_1677) coding for a putative NADPH-P450 reductase (NPR) to support the fungal cytochrome P450 enzymes. The heterologously expressed recombinant M. globosa NPR protein was purified, and its functional features were characterized. The purified protein generated a single band on SDS-PAGE at 80.74 kDa and had an absorption maximum at 452 nm, indicating its possible function as an oxidized flavin cofactor. It evidenced NADPH-dependent reducing activity for cytochrome c or nitroblue tetrazolium. Human P450 1A2 and 2A6 were able to successfully catalyze the O-deethylation of 7-ethoxyresorufin and the 7-hydroxylation of coumarin, respectively, with the support of the purified NPR. These results demonstrate that purified NPR is an orthologous reductase protein that supports cytochrome P450 enzymes in M. globosa.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.338-346
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• 2005

Serum alanine aminotransferase(ALT), aspartate aminotransferase (AST), hepatic glutathione, glutathione S-transferase(GST), cytochrome P450 and cytochrome P450 reductase activity were measured to investigate the effects of hepatic detoxication system and metabolic activities of carbendazim in Sprague Dawley(S.D.) male rat at dose levels of 375, 750 or 1,500 mg/kg body weight. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) activities were slightly increased in all test groups after 120 minutes of administration. Glutathione was increased about 20% at high and medium dose level within 120 minutes after administration, while activity of glutathione S-transferase was decreased $36{\sim}50%$. However, the enzyme activity was recovered from all test groups after 240 minutes of administration. Cytochrome P450 and activity of cytochrome P450 reductase were decreased $25{\sim}50%$ until 120 minutes after administration, but recovered after 240 minutes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.859-866
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• 1995

This study was done to investigate the effects of chronic ethanol feeding on hepatic microsomal cytochrome system, lipid peroxidation and peroxide metabolizing enzyme activities in 2-acetylaminofluorene(2-AAF) treated rats. Male Sprague-Dawley rats, weighing 120~125g, were pair-fed liquid diets containing 35% of total calories either as ethanol or isocaloric carbohydrates for 6 weeks. After 4 weeks of experimental diet feeding, 2-AAF(100mg/kg body weight) was injected twice a week intraperitoneally. Both weight and percent liver weight per body weight were significantly changed by ethanol feeding. Hepatic microsomal lipid peroxide value and the activities of glutathione(GSH) peroxidase and GSH reductase were not changed by either ethanol or 2-AAF treatment. However the analysis of cytochrome systems showed that both ethanol and 2-AAF increased cytochrome P-450 and bs contents although cytochrome P-450 content was moe affected by 2-AAF while cytochrome b5 content by ethanol. Cytosolic GSH S-transferase activity, which is often elevated during chemical carcinogenesis, also significantly increased by either ethanol feeding or 2-AAF treatment. Overall values for the cytochrome contents and GSH S-transferase activities were highest in 2-AAF treated rats fed ethanol. These results might support the hypothesis that the increase in liver cancer risk associated with chronic ethanol consumption might be due to, at least in part, enhancement of carcinogen bioactivation by ethanol.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.983-989
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• 2017

NADPH-P450 reductase (NPR) transfers electrons from NADPH to cytochrome P450 and heme oxygenase enzymes to support their catalytic activities. This protein is localized within the endoplasmic reticulum membrane and utilizes FMN, FAD, and NADPH as cofactors. Although NPR is essential toward enabling the biochemical and pharmacological analyses of P450 enzymes, its production as a recombinant purified protein requires a series of tedious efforts and a high cost due to the use of $NADP^+$ in the affinity chromatography process. In the present study, the rat NPR clone containing a $6{\times}$ Histidine-tag (NPR-His) was constructed and heterologously expressed. The NPR-His protein was purified using $Ni^{2+}$-affinity chromatography, and its functional features were characterized. A single band at 78 kDa was observed from SDS-PAGE and the purified protein displayed a maximum absorbance at 455 nm, indicating the presence of an oxidized flavin cofactor. Cytochrome c and nitroblue tetrazolium were reduced by purified NPR-His in an NADPH-dependent manner. The purified NPR-His successfully supported the catalytic activities of human P450 1A2 and 2A6 and fungal CYP52A21, yielding results similar to those obtained using conventional purified rat reductase. This study will facilitate the use of recombinant NPR-His protein in the various fields of P450 research.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.149.3-150
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• 2003

CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)

• Toxicological Research
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• v.11 no.2
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• pp.215-221
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• 1995

This paper examines the effects of dietary polyunsaturated fatty acid/saturated fatty acid (p/s) ratios and butylated hydroxytoluene (BHT) on the hepatic microsomaI mixed-function oxidase sy. stem in 2~acetylaminofiuorene (2-AAF) treated rats. Sprague-Dawley male rats were fed the diet of beef tallow (p/s 0.08), beef tallow plus soybean oil (p/s 1.0), and soybean oil (p/s 4.0) at the level of 15%fat and with or without 0.3% BHT. After 2-AAF was injected twice at the ages of 23 and 27 weeks, cholesterol/phospholipid molar ratio, thiobarbituric acid reactive substances (TBARS) level, cytochrome P450, cytochrome $b_5$, NADPH-cytochrome $b_5$, and NADPH-cytochrome c reductase activity were measured from isolated hepatic microsomal fractions. In the beef tallow (p/s 0.08) and beef tallow plus soybean oil (p/s 1.0) groups, cholesterol/phospholipid molar ratio showed decreasing tendency by 2-AAF and BHT. Cytochrome P-450 content was decreased in the group of soybean oil (p/s 4.0) and NADPH-cytochrome c reductase activity was increased by 2-AAF and BHT in all the dietary groups. While TBARS levels were increased by 2-AAF in all the dietary groups, they were reduced by BHT in the soybean oil (p/s 4.0) group. These results suggest that long term intake of soybean oil (p/s 4.0) diet induced changes in the nature of microsomal membrane and induced less cytochrome P-450, low level feeding of BHT increased cytochrome c reductase activity and lowered microsomal lipid peroxidation levels, which were increased by 2-AAF treatment.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.148.2-149
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• 2003

Recently we have reported that various hydroxystilbenes show strong inhibition of human cytochrome P450 1 enzyme activities. A series of syntheic trans-stilbene derivatives were prepared and their inhibitory potentials were evaluated with the bacterial membrane of recombinant human cytochrome P450 1A1, 1A2 and 1B1 coexpressed with hyman NADPH-P450 reductase to find a new inhibitor of cytochrome P450 enzymes. Of the compounds tested, SY-081 exhibited a potent inhibition of human cytochrome P450 1B1 with an $IC_50$ value of 2.6 nM. (omitted)

• YAKHAK HOEJI
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• v.39 no.4
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• pp.450-460
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• 1995

The acute toxicity of fthalide in rat was studied in vivo by the observations of the changes in hematogram, serological parameters, content of cytochrome p-450, activities of NADPH-cytochrom c reductase, glucose-6-phosphatase, and the contents of cholinesterase and carboxylesterase in liver. Fthabde is a practically non-toxic substance(LD50 is 3.86g/kg), but rats were intoxicated with fthabde at a oral dose of 100 mg/kg for 12 days. WBC were significantly decreased and activities of ALT and LDH, on the cotrary, the content of glucose in serum were slightly increased. Cytochrome p-450 and lipid peroxide in liver were significantly increased in the fthalide-intoxicated rats. The longer administration of fthalide showed further increase of carboxylesterase activity in liver and serum, but decrease of activities of glucose-6-phosphatase and cholinesterase in liver and serum. These results show that fthatide can induce the hepatocellular injury and neurotoxicity.