• 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.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.246-246
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• 1996

The glucuronide conjugates of morphine have been claimed to exert significant neuropharmacological effects. Morphine-6-glucuronide (M6G) may be a potent opioid agonist in vivo, and morphine-3-glucuronide (M3G) may act as a weak opioid antagonist. The present study addressed the permeability of the blood-brain barrier (BBB) for these metabolites compared to morphine. Tracers were prepared by enzymatic glucuronidation of U-methyl-$^3$H]-morphine. Brain uptake in rats was measured by the internal carotid artery perfusion technique and after i.v. bolus injections. In the perfusion experiments morphine showed a permeability-surface area product (PS) of 3.52${\pm}$0.61 ${\mu}$L min$\^$-1/ g$\^$-1/ Uptake seems to be mediated by passive diffusion and was not saturable by 100 ${\mu}$M morphine in the perfusate. The BBB permeability of [$^3$H]-M3G and [$^3$H]-M6G was too low to be quantified after 5 min of perfusion. Brain uptake of [$^3$H]-M3G and [$^3$H]-M6G 60 min after i.v. bolus injection reached 0.0060${\pm}$0.0003 and 0.0030${\pm}$0.0005% injected dose per g, respectively. From these brain concentrations and from the corresponding plasma concentration - time curves, BBB PS values of 0.14${\pm}$ 0.02 ${\mu}$L min$\^$-1/g$\^$-1/ and 0.11 ${\pm}$ 0.01 ${\mu}$L min$\^$-1/g$\^$-1/, respectively, were calculated. The ratio of BBB PS values is complementary to the analgesic potencies of morphine and M6G after different routes of administration. The low PS of MSG explains, why it is approximate]y equipotent to morphine after systemic injection, although it is about 2 orders of magnitude more potent than morphine after administration directly into the central nervous system.

• Clinical and Experimental Pediatrics
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• 제51권3호
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• pp.262-266
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• 2008

목 적 : GSTs는 glutathione과 친전자성 화합물의 결합을 촉매하여 생체내에 독성 물질로부터 조직을 보호하는 효소로, 여러 다형성이 확인 되었으며 일부 GSTs의 null 유전자형을 가진 사람은 GSTs 단백을 생성하지 못하여 다양한 질병의 감수성에 영향을 미친다고 보고 되었다. 이것은 빌리루빈과 같은 non-substrate ligand와 결합하여 세포내로 운반하는 역할을 하는 대표적인 ligandin이며 빌리루빈을 간세포 내 소포체로 이동시켜 UGT를 통해 glucuronidation 시키는 역할을 한다. 이 연구에서는 빌리루빈 대사의 ligandin인 GSTs 중 GSTM1, GSTT1과 신생아 황달과 연관성이 있는 지 알아보고자 본 연구를 시행하였다. 방 법 : 혈청 빌리루빈 수치가 12 mg/dL 이상인 건강하고 위험인자가 없는 만삭아 중 신생아 고빌리루빈혈증 환아 88명, 대조군은 186명을 대상으로 혈액 0.5 cc를 채혈하여 DNA를 분류하였고 중합효소 연쇄 반응을 수행하여 DNA band를 확인하였다. 결 과 : 대조군의 GSTM1 null 유전형 58.1%, GSTT1의 null 유전형 53.2%였다. 환자군에서 GSTM1 null 유전형은 42% (P=0.0187), GSTT1 null 유전형은 31.8% (P=0.0014)로 통계학적 연관성이 있었다. GSTM1/GSTT1 null/null인 경우, 환자군에서 20명(22.7%)(P=0.0008), GSTM1/GSTT1 null/present인 경우 환자군에서 17명(19.3%) (P=0.0470), GSTM1/GSTT1 present/null인 경우 환자군에서 8명(9.1%) (P=0.0066)으로 나타났다 결 론 : GSTM1과 GSTT1 모두 환자군에서 null 유전형이 대조군에 비하여 더 적게 나타나 GSTs null 유전형이 신생아 고빌리루빈혈증의 위험인자는 아니었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3335-3341
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• 2014

Background: Severe toxicity is commonly observed in cancer patients receiving irinotecan (CPT-11) UDPglucuronosyltransferase1A1 (UGT1A1) catalyzes the glucuronidation of the active metabolite SN-38 but the relationship between UGT1A1 and severe toxicity remains unclear. Our study aimed to assess this point to guide clinical use of CPT-11. Materials and Methods: 89 cancer patients with advanced disease received CPT-11-based chemotherapy for at least two cycles. Toxicity, including GI and hematologic toxicity was recorded in detail and UGT1A1 variants were genotyped. Regression analysis was used to analyse relationships between these variables and tumor response. Results: The prevalence of grade III-IV diarrhea was 10.1%, this being more common in patients with the TA 6/7 genotype (5 of 22 patients, 22.7%) (p<0.05). The prevalence of grade III-IV neutropenia was 13.4%and also highest in patients with the TA 6/7 genotype (4 of 22 patients; 18.2%) but without significance (p>0.05). The retreatment total bilirubin levels were significantly higher in TA6/7 patients (mean, $12.75{\mu}mol/L$) with compared to TA6/6 (mean, $9.92{\mu}mol/L$) with p<0.05. Conclusions: Our study support the conclusion that patients with a $UGT1A1^*28$ allele (s) will suffer an increased risk of severe irinotecan-induced diarrhea, whether with mid-or low-dosage. However, the $UGT1A1^*28$ allele (s) did not increase severe neutropenia. Higher serum total bilirubin is an indication that patients UGT1A1 genotype is not wild-type, with significance for clinic usage of CPT-11.

• 한국식품위생안전성학회지
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• 제29권2호
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• pp.85-91
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• 2014

Deoxynivalenol (DON) and related trichothecene mycotoxins are extensively distributed in the cereal-based food and feed stuffs worldwide. Recent climate changes and global grain trade increased chance of exposure to more DON and related toxic metabolites in poorly managed production systems. Monitoring the biological and environmental exposures to the toxins are crucial in protecting human and animals from toxicities of the hazardous contaminants in food or feeds. Exposure biomarkers including urine DON itself are prone to shift to less harmful metabolites by intestinal microbiota and liver metabolic enzymes. De-epoxyfication of DON by gut microbes such as Eubacterium strain BBSH 797 and Eubacterium sp. DSM 11798 leads to more fecal secretion of DOM-1. By contrast, most of plant-derived DON-glucoside is also easily catabolized to free DON by gut microbes, which produces more burden to body. Phase 2 hepatic metabolism also contributes to the glucuronidation of DON, which can be useful urine biomarkers. However, chemical modification could be very typical depending on the anthropologic or genetic background, luminal bacteria, and hepatic metabolic enzyme susceptibility to the toxins in the diet. After toxin exposure, effect biomarkers are also important in estimating the linkage and mechanisms of foodborne diseases in human and animal population. Most prominent adverse effects are demonstrated in the DON-induced immunological and behavioral disorders. For instance, acutely elevated interleukin-8 from insulted gut exposed to dietaty DON is a dominant clinical biomarker in human and animals. Moreover, subchronic exposure to the toxins is associated with high levels of serum IgA, a biological mediator of IgA nephritis. In particular, anorexia monitoring using mouse models are recently developed to monitor the biological activities of DON-induced feed refusal. It is also mechanistically linked to alteration of serotoin and peptide YY, which are promising biomarkers of neurological disorders by the toxins. As animal-alternative biomonitoring, huamn enterocyte-based assay has been developed and more realistic gut mimetic models would be useful in monitoring the effect biomarkers in resposne to toxic contaminants in the future investigations.