• Toxicological Research
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• 제11권2호
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• pp.273-277
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• 1995

Several metabolic modulators on the generation of carbon monoxide (CO)from dichloromethane (DCM) was examined in adult female rats. It has been known that DCM is converted to CO by cytochrome P-450 or to carbon dioxide $(CO_2)$ by glutathione-dependent metabolic reaction. In rats treated with DCM (3 mmol/kg, ip) only, the carboxyhemoglobin (COHb) level reached a peak of approximately 10% 2 or 3 hr following the treatment. Disulfiram (300 mg/kg, ip) or allylsulfide (200 mg/kg, po), both known as a selective inhibitior for cytochrome P-450 2E1, blocked the increase in COHb concentratlons almost completely suggesting that the metabolic conversion of DCM to CO is mediated by the activity of this specific type of isozyme. YH439 (125 or 250 mg/kg, po), a potential hepatoprotective agent, decreased the COHb elevation as well indicating that this chemical is a potent inhibitor for 2E1. In rats treated with pyrazine (200 mg/kg, ip) 18 hr prior to DCM the peak COHb concentration was decreased by approximately 3 or 4%. However, pretreatment of rats with pyrazine either 24 or 48 hr before DCM increased the peak COHb concentration significantly compared to the rats treated with DCM only. The results in the present study strongly suggest that the generation of CO from DCM depends on the 2E1 activity and that the pharmacological and/or toxicological action of YH439 or pyrazine in animals or human is associated with its effect on this isozyme.

• 한국식품영양과학회지
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• 제25권6호
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• pp.969-975
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• 1996

본 연구는 streptozotocin 유발 당뇨쥐의 간과 폐조직에서의 MFO계 활성 변화 및 지질과산화에 미치는 vitamin E의 영향을 관찰하고자 본 실험을 행하였다. 체중 140g 정도의 Sparague-Dawley종 숫컷을 대조군(40mg vitamin E/kg diet group)과 당뇨유발 실험군으로 나눈 후 실험군은 다시 식이내 vitamin E 공급수준에 따라 DM-0E군(0mg vitamin E/kg diet group), DM-40E군(40mg vitamin E/kg diet group), DM-400E군(400mg vitamin E/kg diet group) 나누어 4주간 사육한 후 대조군을 제외한 실험군을 STZ로 당뇨를 유발시켰다. 당뇨유발 6일 후 쥐를 희생시켜 간조직 및 폐조직 microsome 중의 cytochrome P$_{450}$ 및 cytochrome b$_{5}$함량과 NADPH-cytochrome P$_{450}$ reductase 활성도를 측정하고 아울러 microsome내의 지질과산화물을 측정하여 다음과 같은 결과를 얻었다. 1. 간조직 중의 cytochrome P$_{450}$ 함량은 대조군에 비해 DM-0E군, DM-40E 군 및 DM-400E군이 각각 162%, 150%, 56% 증가하였으며 또 DM-400E군은 DM-0E, DM-40E군에 비해 낮았다. 폐조직 중의 cytochrome P$_{450}$ 함량도 간조직에 비해 함량은 낮았지만 경향은 비슷하였다. 2. 간조직 중의 cytochrome b$_{5}$은 대조군에 비해 DM-0E군, DM-40E군은 각각 70%, 53%씩 증가하였으나 DM-400E군은 대조군 수준이었다. 폐조직 중의 cytochrome b$_{5}$함량도 대조군에 비 해 DM-0E, DM-40E 및 DM-400E군에서 각각 149%, 116%, 50%씩 증가하였다. 3. 간조직에서의 cytochrome P$_{450}$ reductase 활성은 대조군에 비해 DM-0E군은 58%, DM-40E군에서는 47% 증가하였으며 DM-400E는 대조군 수준이었다. 폐조직에서도 간조직에서와 비슷한 경향이었다. 4. 간조직의 지질과산화물가는 대조군에 비해 DM-0E군, DM-40E군, DM-400E군이 각각 143%, 95%, 31%씩 높았다. 또 DM-400E군은 DM-0E, DM-40E군에 비해 약 50% 정도 낮았다. 폐조직에서도 경향은 비슷했는데 간조직 보다 과산화적 손상이 다소 높았다. 이상의 결과에서 STZ 유발 당뇨쥐에서는 MFO system의 활성이 증가되고 지질과산화가 촉진되었다. 그러나 식이 중의 vitamin E의 적절한 공급은 MFO system 활성이 저하되고 과산화적 손상이 현저하게 완화됨을 볼 수 있었다.

• BMB Reports
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• 제32권3호
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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.

• 대한한의학방제학회지
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• 제29권4호
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• pp.277-283
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• 2021

Objectives : We investigated the effects of Bojungikgi-tang (BJIGT) on P450 cytochrome enzyme and oxidative stress in the cells. Methods : We enrolled the HepG2 hepatocyte cell line to assess MTT assay, flow cytometer, and immunoblotting analysis. Expression of CYP450 was confirmed by immunoblotting analysis in the Huh7 cell line. Results : We determined that BJIKT markdely changed the expression of the CYP2C19, CYP2D6, and CYP2E1. Moreover, BJIKT inhibited the cell toxicity induced by arachidonic acid + iron treatment, as assessed by FACS analysis. BJIKT induced AMPK activation, which increased the phophorylation of ACC. Conclusions : This study verified the effects of BJIKT, on P450, ROS production, mitochondrial damage and AMPK signaling pathway, which might give us the scientific information about the traditional herbal prescription.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.940-945
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• 2002

The present study was done to determine the effect of trolox C, a hydrophilic analogue of vitamin E, on hepatic injury, especially the alteration in cytochrome P-450 (CYP)-dependent drug metabolism during ischemia and reperfusion (I/R). Rats were subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Rats were treated intravenously with trolox C (2.5 mg/kg) or vehicle (PBS, pH 7.4), 5 min before reperfusion. Serum alanine aminotransferase and lipid peroxidation levels were markedly increased after I/R. This increase was significantly suppressed by trolox C. Cytochrome P-450 content was decreased after I/R but was restored by trolox C. There were no significant differences in ethoxyresorufin O-dealkylase (CYP 1A1) and methoxyresorufin O-dealkylase (CYP 1A2) activities among any of the experimental groups. Pentoxyresorufin O-dealkylase (CYP 2B1) activity was decreased and aniline p-hydroxylase (CYP 2E1) activity was increased after I/R. Both these changes were prevented by trolox C. Our findings suggest that trolox C reduces hepatocellular damage as indicated by abnormalities in microsomal drug-metabolizing function during I/R, and that this protection is, in part, caused by decreased lipid peroxidation.

• 대한예방한의학회지
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• 제16권3호
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• pp.129-137
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• 2012

Objective : Herb-drug interactions have become an important issue because of the consumption of herbal remedies has increased in the world. Yangguksanhaw-tang (Liang ge san huo-tang) and Taeumjowi-tang (Tai yin tiao wei-tang) are typical herbal formulas on Sasang constitution medicine (four-constitution medicine). This study was aimed at evaluating the effects of Yangguksanhaw-tang and Taeumjowi-tang on drug metabolizing enzymes, cytochrome P450 (CYP450) isozymes. Methods : Vivid$^{(R)}$ CYP450 Screening Kits were used to measure of CYP3A4, CYP2C19, CYP2D6 and CYP2E1 activities. This method is based on the use of fluorescent CYP450 substrates that are efficiently metabolized by specific CYP450 isozymes to yield a product with altered fluorescent properties. The percent inhibitions of CYP450s by herbal formulas were calculated. Results : Yangguksanhaw-tang inhibited CYP2C19 and CYP2E1 activities higher than that other CYP450 isozymes. The $IC_{50}$ values of CYP2C19 and CYP2E1 were 159.83 ${\mu}g/mL$ and 261.40 ${\mu}g/mL$, respectively. The CYP2E1 activity was inhibited ($IC_{50}=215.17{\mu}g/mL$) higher than that other CYP450 isozymes by Taeumjowi-tang. Conclusions : These results suggest that Yangguksanhaw-tang may inhibit the metabolism of co-administered drugs whose primary route of metabolism is via CYP2C19 or CYP2E1. Taeumjowi-tang could inhibit the metabolism of co-administered drugs, which are substrates for CYP2E1. Therefore, co-administration of the herbal formulas and other conventional drugs should be undertaken with care.

• Preventive Nutrition and Food Science
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• 제8권2호
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• pp.130-136
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• 2003

The protective effects of onion extract (OE), onion powder extracted in ethanol for 2 days. on carbon tetrachloride ($CCl_4$)-induced hepatotoxicities and the possible mechanisms involved in this protection were investigated in mice. Pretreatment with OE prior to the administration of $CCl_4$ significantly reduced the increase in serum alanine and aspartate aminotransferase activities and hepatic lipid peroxidation in a dose-dependent manner. In addition, pretreatment with OE significantly prevented the depletion of reduced glutathione content in the liver of $CCl_4$-intoxicated mice. $CCl_4$-induced hepatotoxicity was also prevented, as indicated by a liver histopathologic findings. The effects of OE on the cytochrome P450 (P450) 2E1, the major isozyme involved in $CCl_4$ biotransformation were investigated. Treatment of mice with OE resulted in a significant decrease in P450 2E1-dependent p-nitrophenol and aniline hydroxylation in a dose-dependent manner. Consistent with these observations, the P450 2E1 expressions were also decreased, as determined by immunoblot analysis. OE also exhibited antioxidant effects in FeCl$_2$-ascorbate induced lipid peroxidation in rat liver homogenates and in superoxide radical scavenging activity. These results show that the protective effects of OE against the $CCl_4$-induced hepatotoxicity may be due to its ability to block bioactivation of $CCl_4$, mainly tty inhibiting the expression and activities of P450 2E1 and by scavenging free radicals.

• 한국환경보건학회지
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• 제29권3호
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• pp.9-15
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• 2003

The modification of CYP2El activity is a matter of considerable interest because of its role in the metabolic activation of a variety of environmental toxicants. In the present study, the time-course of changes in human CYP2El activities was determined following treatment with solvents (acetone, dimethylsulphoxide or pyridine) using intact HepG2 cells transfected by human CYP2El. Hydroxylation of chlorzoxazone was used for the measurement of CYP2El activity. CYP2E1 protein level was increased upon cultivation of cells in the presence of the solvents for 24 hr. Determination of CYP2El activities after 24 ht cultivation with the solvents demonstrated that acetone or dimethylsulphoxide increased, whereas pyridine inhibited the activities. This differential effect of the solvents on CYP2El activities persisted to subsequent 24 ht. Competitive inhibition study suggested that pyridine has stronger binding affinity to CYP2E1 than acetone or dimethylsulphoxide. These results demonstrate that different binding affinity of the solvents to CYP2El plays important role in determining real CYP2El activity in intact cells after exposure to the solvents. Present study would be helpful in precise understanding of human CYP2El-mediated toxicity.

• Applied Biological Chemistry
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• 제38권5호
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• pp.463-467
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• 1995

생쥐(Balb/C) 간과 신장의 microsomal cytochrome P-450 효소계에 의한 ${\alpha}$-endosulfan의 시험관내 대사시험을 수행하였다. ${\alpha}$-Endosulfan은 endosulfan lactone(EL), endosulfan hydroxyether(EHE), endosulfan alcohol(EA), endosulfan sulfate(ES), endosulfan ether(EE) 그리고 ${\beta}$-endosulfan(${\beta}$-E) 등으로 대사되었으며 주요 대사산물은 간에서 EL(13.2%) 및 EA(11.5%)이었으며 신장에서 EA(17.4%) 및 EHE(19.3%)이었다. Microsome 배양액중 유기용매 추출성 대사산물은 63.4%이었으며 수용성 대사산물은 37.1%이었다. 수용성 대사산물은 EA(83.9%), EHE(4.5%) 그리고 ES(2.3%)로서 주요 수용성 대사산물은 EA이었다. Piperonyl butoxide는 ${\alpha}$-endosulfan으로부터 EE의 생성을 86%, EA의 생성을 92% 그리고 EHE, EL 및 ES의 생성을 대부분 저해하였다.

• 동의생리병리학회지
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• 제21권6호
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• pp.1415-1423
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• 2007

Carbon tetrachloride ($CCl_4$)-induced liver injury depends on a toxic agent that has to be metabolized by the liver NAPDH-cytochrome P450 enzyme system to a highly reactive intermediate. Alternations in the activity of cytochrome P450 enzymes affect the susceptibility to hepatic injury from $CCl_4$. In this study, we evaluated the potential protective activity of the traditional Korean medicinal herb, Corni fructus (CF), against an experimental model of hepatotoxicity induced by $CCl_4$. The CF exhibited a hepatoprotective activity against $CCl_4-induced$ liver damage in Sprague-Dawley (SD) rats, as measured by GOT, GPT, ALP and histological observation. The CF also showed significant decrease of malodialdehyde (MDA) and increase of glutathion (GSH), catalase activity in rat liver homogenate. In addition, the expression of CYP2E1, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, was significantly decreased in the liver of CF treated SD rats. But $CCl_4$ and CF has no significant effect on 1A1 and 3A1 isoform of cytochrome P450. Based on these findings, it is suggested that hepatoprotective effects of CF possibly related to antioxidative effects and regulation of CYP2E1 expression.