Evaluation of 3,3',4'-trihydroxyflavone and 3,6,4'-trihydroxyflavone (4'-O-glucuronidation) as the in vitro functional markers for hepatic UGT1A1.
Evaluation of 3,3',4'-trihydroxyflavone and 3,6,4'-trihydroxyflavone (4'-O-glucuronidation) as the in vitro functional markers for hepatic UGT1A1.
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DOI：
10.1021/mp200300w
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发表时间：
2011-12-05
影响因子：
4.9
通讯作者：
Hu M
中科院分区：
文献类型：
--
作者：
Wu B;Zhang S;Hu M
识别UDP-葡萄糖醛酸基转移酶(UGT)选择性探针(主要由单一异构体葡萄糖醛酸化的底物)由于酶的大量重叠底物专一性而变得复杂。本文利用3，3‘，4’-三羟基黄酮(33‘4’-THF)和3，6，4‘-三羟基黄酮(364’-THF)的区域选择性葡萄糖醛酸化反应来研究肝脏UGT1A1的活性。用12种重组人UGT异构体和混合人肝微粒体(PHLM)测定了33‘4’THF和364‘THF的葡萄糖醛酸化动力学。用相对活性因子法估算了UGT主要异构体在PHLM中对两种黄酮类化合物代谢的个体贡献。使用包括3个UGT1A1*1*1、β-1A1*1*28和UGT1A1*1*1、UGT1A1*1*28和UGT1A1*28*28的HLM库(n=12)，使用黄酮类-4‘-O-葡萄糖醛酸化和UGT1A1-3-葡萄糖醛酸化或SN-38葡萄糖醛酸化对UGT1A1活性进行相关性分析。结果表明，UGT1A1和1A9是糖醛酸化反应的主要异构体，其次是1A7，其中UGT1A1分别占33‘4’THF和364‘THF 4’-O-葡萄糖醛酸化反应的92±7%和91±10%，UGT1A9占3-O-葡萄糖醛酸化反应的大部分。在12个HLM中，黄酮类4‘-O-葡萄糖醛酸化速率与雌二醇-3-葡萄糖醛酸化速率或SN-38葡萄糖醛酸化速率之间存在极显著的相关性(R2>；0.944，p<；0.0001)。总之，UGT1A1介导的33‘4’THF和364‘THF的4’O-葡萄糖醛酸化反应与雌二醇(3-OH)和SN-38的葡萄糖醛酸化反应高度相关。本研究首次证明了黄酮类化合物的区域选择性葡萄糖醛酸化反应可用于体外检测肝脏UGT1A1活性。
Identifying UDP-glucuronosyltransferase (UGT)-selective probes (substrates that are primarily glucuronidated by a single isoform) is complicated by the enzymes' large overlapping substrate specificity. Here, regioselective glucuronidation of two flavonoids 3,3′,4′-trihydroxyflavone (33′4′THF) and 3,6,4′-trihydroxyflavone (364′THF) is used to probe the activities of hepatic UGT1A1. The glucuronidation kinetics of 33′4′THF and 364′THF was determined using 12 recombinant human UGT isoforms and pooled human liver microsomes (pHLM). The individual contribution of main UGT isoforms to the metabolism of the two flavonoids in pHLM was estimated using the relative activity factor approach. UGT1A1 activity correlation analyses using flavonoids-4′-O-glucuronidation vs. β-estradiol-3-glucuronidation (a well-recognized marker for UGT1A1) or vs. SN-38 glucuronidation were performed using a bank of HLMs (n=12) including three UGT1A1-genotyped HLMs (i.e., UGT1A1*1*1, UGT1A1*1*28 and UGT1A1*28*28). The results showed that UGT1A1 and 1A9, followed by 1A7, were the main isoforms for glucuronidating the two flavonoids, where UGT1A1 accounted for 92 ± 7 % and 91 ± 10 % of 4′-O-glucuronidation of 33′4′THF and 364′THF, respectively, and UGT1A9 accounted for most of the 3-O-glucuronidation. Highly significant correlations (R2 > 0.944, p < 0.0001) between the rates of flavonoids 4′-O-glucuronidation and that of estradiol-3-glucuronidation or SN-38 glucuronidation were observed across 12 HLMs. In conclusion, UGT1A1-mediated 4′-O-glucuronidation of 33′4′THF and 364′THF were highly correlated with glucuronidation of estradiol (3-OH) and SN-38. This study demonstrated for the first time that regioselective glucuronidation of flavonoids can be applied to probe hepatic UGT1A1 activity in vitro.
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影响因子：
6.1
作者：
Singh, Rashim;Wu, Baojian;Hu, Ming
通讯作者：
Hu, Ming
影响因子：
3.9
作者：
Ohno, Shuji;Nakajin, Shizuo
通讯作者：
Nakajin, Shizuo
影响因子：
3.9
作者：
Ohno, Shuji;Kawana, Kiyoshi;Nakajin, Shizuo
通讯作者：
Nakajin, Shizuo
影响因子：
3.9
作者：
Fujiwara, Ryoichi;Nakajima, Miki;Yokoi, Tsuyoshi
通讯作者：
Yokoi, Tsuyoshi
DOI：
10.1073/pnas.95.14.8170
发表时间：
1998-07-07
影响因子：
11.1
作者：
Beutler, E;Gelbart, T;Demina, A
通讯作者：
Demina, A