• 대한한의학회지
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• 제24권2호
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• pp.40-46
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• 2003

Objectives : Achyranthes bidentata radix (Usul) has been used as anti-arthritic, antiallergic, antidiuretic, and so on. Recently extracts of Achyranthes bidentata radix have shown anti-inflammatory and cancer preventive effects in vitro and in vivo. Methods : We therefore evaluated the inhibitory potential of ethanol extracts of Achyranthes bidentata radix on cytochrome P450 (CYP) isoforms-catalyzed reactions, which relate to causes of cancer and inflammation, including CYP1A2, CYP2C9, CYP2C19, CYP2E1, CYP2D6, CYP2C8, and CYP3A4, using human liver microsomal preparations. Results : The extracts showed weak or negligible inhibitory effects on CYP2C9-catalyzed (S)-warfarin 7-hydroxylation, CYP2C19-catalyzed S-mephenytoin 4-hydroxylation, and CYP2D6-catalyzed dextromethorphan O-demethylation with each IC50 over 1750 g/ml, respectively. However, it showed relatively significant inhibitory effect on CYP1A2-catalyzed phenacetin O-deethylation and CYP2E1-catalyzed chlorzoxazone 6-hydroxylation with IC50s of 970.5 g/ml and 821.4 g/ml, respectively. Conclusions : These results suggest that extracts of Achyranthes bidentata radix have inhibitory effects on CYP-catalyzed reactions, especiallyCYP1A2 and CYP2E1, in human liver microsomes. These effects appear to relate to anti-inflammatory and cancer prevention following decrease of reactive oxygen species formed by CYP, especially CYP1A2 and CYP2E1, by Achyranthes bidentata radix. However, further evaluation is necessary to demonstrate and to confirm its effects in human.

• 한국환경보건학회지
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• 제30권3호
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• pp.230-238
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• 2004

The adverse health effects of a number of environment pollutions are related to the formation of free radicals. Induction of antioxidant defensive system in the response to an oxidative attack is an essential element of the cell to survive. CYP2E1 is easily induced by organic solvents and induces continuous formation of reactive oxygen species (ROS). ${\gamma}$-Glutamyltranspeptidase (${\gamma}$GT) plays an important role in glutathione metabolism and xenobiotic detoxification. To evaluate the characteristic of oxidative stress which induces GGT expression and to understand human antioxidant defensive response against oxidative stress induced by CYP2E1, we studied regulation of ${\gamma}$GT enzyme expression in response to various oxidative stresses in human HepG2 cells. The ${\gamma}$GT activity was not modified after exposure of acute oxidative stress inducing agents (ferric nitrilotriacetate, cumene hydroperoxide, ADP-Fe, O-tetradecanoylphorbol-13-acetate, tumor necrosis factor-alpha). To induce continuous exposure of cells to ROS, HepG2 cells were transfected by human CYP2E1 gene transiently. The CYP2E1 activity was verified with chlorzoxazone hydroxylation. Transfection of CYP2E1 showed continuous 60% increase in intracellular ROS and 240 % increase in microsomal ROS. CYP2E1 overexpressing cells showed increased ${\gamma}$GT activity (2.5-fold). The observed enhancement of ${\gamma}$GT activity correlated with a significant increase of ${\gamma}$GT mRNA (2.1-fold). Treatment with antioxidant strongly prevented the increase in ${\gamma}$GT activity. The CYP2E1 overexpression did not modify toxicity index and increased glutathione levels. These results show that continuous exposure of cells to ROS produced by CYP2E1 up-regulates ${\gamma}$GT; This may be one of the adaptive antioxidant responses of cells to oxidative insult. Present study also suggests that the induction of ${\gamma}$GT could be used as a marker of oxidative stress induced by exposure to organic solvents.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1659-1664
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• 2012

TSAHC [4'-(p-toluenesulfonylamido)-4-hydroxychalcone] is a promising antitumorigenic chalcone compound, especially against TM4SF5 (four-transmembrane L6 family member 5)-mediated hepatocarcinoma. We evaluated the potential of TSAHC to inhibit the catalytic activities of nine cytochrome P450 isoforms and of P-glycoprotein (P-gp). The abilities of TSAHC to inhibit phenacetin O-deethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), amodiaquine N-deethylation (CYP2C8), diclofenac 4-hydroxylation (CYP2C9), omeprazole 5-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and midazolam 1'-hydroxylation (CYP3A) were tested using human liver microsomes. The P-gp inhibitory effect of TSAHC was assessed by [$^3H$]digoxin accumulation in the LLCPK1-MDR1 cell system. TSAHC strongly inhibited CYP2C8, CYP2C9, and CYP2C19 isoform activities with $K_i$ values of 0.81, 0.076, and $3.45{\mu}M$, respectively. It also enhanced digoxin accumulation in a dose-dependent manner in the LLCPK1-MDR1 cells. These findings indicate that TSAHC has the potential to inhibit CYP2C isoforms and P-gp activities in vitro. TSAHC might be used as a nonspecific inhibitor of CYP2C isoforms based on its negligible inhibitory effect on other P450 isoforms such as CYP1A2, CYP2A6, CYP2B6, CYP2D6, CYP2E1, and CYP3A.

• 생명과학회지
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• 제17권3호통권83호
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• pp.334-339
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• 2007

본 연구는 우황청심원을 비롯한 상용되는 20종의 한약제제를 대상으로 9종의 시토크롬 동종효소에 대한 대사능의 저해정도를 고속 스크리닝 기법을 이용하여 탐색함으로써, 한약제제와 약물의 병용으로 인한 약물 상호작용 가능성을 평가하고자 하였다. 인체 간 마이크로좀 시료에 9종의 주요 시토크롬 약물대사효소의 지표약물과NADPH-generating system및 한약제제(500 ${\mu}g/ml$)를 첨가한 후 $37^{\circ}C$에서 15분간 반응시켜 생성된 각각의 대사물을 LC/MS/MS를 이용하여 정량하여 시토크롬 동종효소 활성의 변화를 평가하였다. 그 결과 우황청심원 현탁액 및 황련해독탕 물 추출물이 각각 CYP2B6 및 CYP2D6 효소 활성을 선택적으로 강력하게 저해하였다. 이러한 결과는 약국에서 쉽게 구입할 수 있는 한약제제들 중 일부는 인체 간 시토크롬 활성 저해능을 가지고 있고, 이들 효소에 의해 대사되는 약물과의 병용 복용시 약물상호작용 발생 가능성이 있음을 의미한다. 향후 한약제제에서 저해능을 나타내는 주된 성분을 규명하여 이 성분의 저해능과 저해 기전을 살피는 노력이 필요할 것이다.