• Molecular & Cellular Toxicology
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• 제3권4호
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• pp.267-272
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• 2007

Environmental and anthropogenic changes affect the health and stability of marine ecosystem. In this study we aimed to identify molecular biomarkers for ecotoxicological pollutants risk assessment in the rockfish (Sebastes schlegeli). We designed primers based on conserved sequences by multiple alignments of target genes from related species, and cloned the partial cDNAs of cytochrome P450 (CYP1A1), glutathione S-transferase (GST), metallothionein (MT), superoxide dismutase (SOD), ubiquitin (UB), vitellogenin (VTG) and $\beta$-actin by reverse transcription polymerase chain reaction (RT-PCR) from S. schlegeli. Northern blot results indicated that these six genes expressions were significantly induced by benzo[a]pyrene (BaP, 1 ${\mu}M$) and that the level of each of their transcripts increased in BaP-exposed rockfish in a time-dependent manner. This study suggests that transcriptional changes in these six genes may be used for monitoring environmental exposure to polycyclic aromatic hydrocarbons (PAHs).

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.438-445
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• 2009

We investigated global gene expression from both mouse liver and mouse hepatic cell lines treated with acetaminophen (APAP) in order to compare in vivo and in vitro profiles and to assess the feasibility of the two systems. During our analyses of gene expression profiles, we picked up several down-regulated genes, such as the cytochrome P450 family 51 (Cyp51), sulfotransferase family cytosolic 1C member 2 (Sult1c2), 3-hydroxy-3-methylglutaryl-Coenzyme A synthase 1 (Hmgcs1), and several genes that were up-regulated by APAP, such as growth arrest and DNA-damage-inducible 45 alpha (Gadd45a), transformation related protein 53 inducible nuclear protein 1 (Trp53inp1) and zinc finger protein 688 (Zfp688). For validation of gene function, synthesized short interfering RNAs (siRNAs) for these genes were transfected in a mouse hepatic cell line, BNL CL.2, for investigation of cell viability and mRNA expression level. We found that siRNA transfection of these genes induced down-regulation of respective mRNA expression and decreased cell viability. siRNA transfection for Cyp51 and others induced morphological alterations, such as membrane thickening and nuclear condensation. Taken together, siRNA transfection of these six genes decreased cell viability and induced alteration in cellular morphology, along with effective inhibition of respective mRNA, suggesting that these genes could be associated with APAP-induced toxicity. Furthermore, these genes may be used in the investigation of hepatotoxicity, for better understanding of its mechanism.

• Toxicological Research
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• 제17권
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• pp.127-133
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• 2001

Together with cytochrome P450 (CYP), flavin-containing monooxygenase (FMO) present in liver microsomes oxidizes various endogenous and exogenous chemicals. In an effort to determine the human FMO activity, we have developed two non-invasive urine analysis methods using caffeine (CA) and ranitidine (RA) as the probe compounds. As the production of theobromine (TB) and ranitidine N-oxide (RANO) from CA and RA is catalyzed primarily by the hepatic FMO, we have assigned the urinary molar ratios of TB/CA and RA/RANO as the in vivo FMO activity. In 200 age-matched Korean volunteers, the obtained TB/CA ratio ranged from 0.4 to 15.2 (38-fold difference) and the RA/RANO ratio from 5.7 to 27.2 (4.8-fold). The FMO activity of 20's, determined by caffeine metabolism, was the highest (2.5$\pm$l.9) and those of 30's, 40's, 50's, 60's and 70's were 40%, 50%, 24%, 39% and 36% of the 20's, respectively. Intake of grapefruit juice, known to contain flavonoids, inhibited the in vivo FMO (TB/CA) activity by 79%. Addition of the flavonoids like naringin, quercitrin and kaempferol, present in grapefruit juice, to the in vitro microso-mal FMO assay, thiobenzamide S-oxidation, produced 75%, 70% and 60% inhibition, respectively. Obtained Ki values of quercitrin, kaempferol and naringin on the in vitro FMO activity were 6.2, 12.0 and 13.9 $\mu\textrm{M}$, respectively. This suggested that the dose of drug should need to be adjusted to suit the individual FMO activities when the drugs metabolized by FMO are given to patients. As the intake of grapefruit juice has been identified to inhibit the FMO as well as CYP3A4 and lA2 activities, patients taking drugs metabolized by these enzymes should not drink grapefruit juice as the carrier.

• Journal of Preventive Medicine and Public Health
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• 제35권3호
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• pp.221-228
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• 2002

Objectives : The purpose of this study was to find the protective effects of garlic on the halogenated hydrocarbon induced hepatotoxicities, and the possible protection mechanisms involved. Methods : Male Sprague-Dawley rats received garlic (0.5%) or regular diet, for 4 weeks. This was followed by a single dose of corn oil (the controls), carbon tetrachloride (400mg/kg body weight) and trichloroethylene (2,000mg/kg body weight) being administered to each diet group. Blood samples were collected 24 hours fellowing the administration, and the serum aspartate aminotransferase (AST) and alanine aminotransferase (ALD activities measured. The liver samples were studied for their cytochrome P450 and CYP2E1 contents, lipid peroxidation and histopathology. Results : rho results for the group receiving the 9.5% garlic diet showed a slight decrease of CYP2E1 expression compared with the regular diet group. Carbon tetrachloride was significantly decreased the CYP2E1 contents in both the regular and garlic diet groups, but the trichloroethylene remained unchanged. Garlic did not decrease the lipid peroxidation of the liver in the control group, but attenuated the increase of lipid peroxidation caused by carbon tetrachloride. Garlic attenuated the increase of both the serum AST and ALT activities caused by carbon tetrachloride. The histopathelogical observations also showed that garlic attenuated centrilobular necrosis and vacuolar degenerative changes significantly in the carbon tetrachloride treated group. Conclusions : The results indicate that garlic attenuates the carbon tetrachloride-induced hepatotoxicity, through the prevention of the metabolic activation and lipid peroxidation.

• Environmental Analysis Health and Toxicology
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• 제21권3호
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• pp.291-299
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• 2006

The experiments investigated whether early exposure to testosterone propionate (TP) during prepuberty alters testis development in Sprague-Dawley male rats. We performed Hershberger assay using the stimulated weanling male rats by OECD protocols, cDNA microarray, and Western blot. TP was subcutaneously injected to uncastrated Sprague-Dawley male rat of 22 days old for 10 consecutive days at doses of 0.4, 0.8, 1.0, 1.2, 1.6 mg/kg per day. At necropsy, the following tissues were removed and weighed: combined testes, epididymides (Epi), Cowper's glands (COW), levator am, and bulbocavernosus muscles (LABC), seminal vesicles, together with coagulating gland (SV) and ventral prostate (VP). We found that TP increased the weights of Epi, VP, SV, COW, and LABC, while testis was decreased in a dose-dependent manner. In cDNA microarray analysis of testis, there were significant reductions in the expression of cytochrome P450 11A (CYP11A), the rate-limiting enzyme of steroidogenesis. Taken together these results, TP exposure before puberty in male rats may produce the delay in testis development by inhibiting the CYP11A gene expression.

• Journal of Chest Surgery
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• 제41권3호
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• pp.354-359
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• 2008

배경: 와파린은 항응고제로 쓰이는 약물로서 주로 간 대사에 의해 배설되는 약물이다. 리팜핀은 결핵 혹은 심내막염 등에 쓰이는 항생제로 2C9과 3A4를 포함한 CYP계열 효소 유도를 일으키는 대표적인 약물이다. 따라서 두 약물을 병용할 경우 리팜핀의 효소 유도에 의한 와파린 대사율 증가로 와파린의 항응고 효과는 감소한다. 이에 따라 와파린의 적절한 용량 조절이 요구되나 정확한 증량과 감량 정도는 제시되지 못하고 있는 실정이다. 이에 본 연구에서는 와파린 복용 환자 중 리팜핀을 병용하게 된 환자를 대상으로 두 약물의 병용 전후, 상호작용의 정도를 시간 경과에 따라 평가하고, 상호작용에 영향을 미치는 요인을 분석하고 또한 이를 토대로 두 약물의 병용 전후, 임상에서 활용할 수 있는 와파린 용량 결정 방법을 설정하고자 하였다. 대상 및 방법: OO병원 항응고 치료 상담 팀의 상담기록지를 1998년 1월부터 2006년 9월까지 후향적으로 검토하여 리팜핀을 병용하게 된 환자를 대상으로 하였다(n=15). 결과: 리팜핀 병용 전 전체 환자의 평균 INR은 $2.25{\pm}0.52$이며 병용 초기 100일간의 평균 INR은 $1.98{\pm}0.28$이었다. 이 경우 병용 전과 병용 초기의 평균 INR은 유의한 차이가 없었다(paired t-test, p>0.05). 리팜핀 병용 중단 직전 2회 측정한 INR의 평균은 $2.19{\pm}0.34$이고 병용 중단 이후 INR의 평균은 $2.49{\pm}0.43$으로 병용 중단 전과 후의 INR 평균은 유의한 차이를 보였으나(paired t-test, p<0.05)모두 치료유효역 범위 내에 있었다. 결론: 항응고 치료 상담 팀의 용량 조절이 적절하다고 판단하여 항응고 치료 상담 팀의 조절을 근거로 병용 시작 시와 병용 중단시의 와파린 용량조절 수식을 도출해냈다

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.10.1-10.8
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• 2016

Objectives Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H295R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. Methods Cortisol, aldosterone, testosterone, and $17{\beta}$-estradiol were evaluated in the H295R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/ 17/19/21) and the hydroxysteroid dehydrogenases ($3{\beta}$-HSD2 and $17{\beta}$-HSD1/4). Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. Results H295R cells exposed to EGb761 (10 and $100{\mu}g/mL$) showed a significant decrease in $17{\beta}$-estradiol and testosterone, but no change in aldosterone or cortisol. Genes (CYP19 and $17{\beta}$-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. EGb761 treatment of H295R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. The coding sequence/Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. Conclusions These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and $17{\beta}$-HSD1, and lead to a decrease in $17{\beta}$-estradiol and testosterone. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer.

• Mass Spectrometry Letters
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• 제9권1호
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• pp.24-29
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• 2018

DC23, a triazolothione resorcinol analogue, is known to inhibit heat shock protein 90 and pyruvate dehydrogenase kinase which are up-regulated in cancer and diabetes, respectively. This study was performed to elucidate the metabolism of DC23 in human liver microsomes (HLMs). HLMs incubated with DC23 in the presence of uridine 5'-diphosphoglucuronic acid (UDPGA) and/or ${\beta}$-nicotinamide adenine dinucleotide phosphate (NADPH) resulted in the formation of four metabolites, M1-M4. M1 was identified as DC23-N-Oxide, on the basis of LC-MS/MS analysis. DC23 was further metabolized to its glucuronide conjugates (M2, M3, and M4). In vitro metabolic stability studies conducted with DC23 in HLMs revealed significant glucuronide conjugation with a $t_{1/2}$ value of 1.3 min. The inhibitory potency of DC23 on five human cytochrome P450s was also investigated in HLMs. In these experiments, DC23 inhibited CYP2C9-mediated tolbutamide hydroxylase activity with an $IC_{50}$ value of $8.7{\mu}M$, which could have implications for drug interactions.