Regioselective Glucuronidation of Diosmetin and Chrysoeriol by the Interplay of Glucuronidation and Transport in UGT1A9-Overexpressing HeLa Cells.
This study aimed to determine the reaction kinetics of the regioselective glucuronidation of diosmetin and chrysoeriol, two important methylated metabolites of luteolin, by human liver microsomes (HLMs) and uridine-5'-diphosphate glucuronosyltransferase (UGTs) enzymes. This study also investigated the effects of breast cancer resistance protein (BCRP) on the efflux of diosmetin and chrysoeriol glucuronides in HeLa cells overexpressing UGT1A9 (HeLa-UGT1A9). After incubation with HLMs in the presence of UDP-glucuronic acid, diosmetin and chrysoeriol gained two glucuronides each, and the OH-in each B ring of diosmetin and chrysoeriol was the preferable site for glucuronidation. Screening assays with 12 human expressed UGT enzymes and chemical-inhibition assays demonstrated that glucuronide formation was almost exclusively catalyzed by UGT1A1, UGT1A6, and UGT1A9. Importantly, in HeLa-UGT1A9, Ko143 significantly inhibited the efflux of diosmetin and chrysoeriol glucuronides and increased their intracellular levels in a dose-dependent manner. This observation suggested that BCRP-mediated excretion was the predominant pathway for diosmetin and chrysoeriol disposition. In conclusion, UGT1A1, UGT1A6, and UGT1A9 were the chief contributors to the regioselective glucuronidation of diosmetin and chrysoeriol in the liver. Moreover, cellular glucuronidation was significantly altered by inhibiting BCRP, revealing a notable interplay between glucuronidation and efflux transport. Diosmetin and chrysoeriol possibly have different effects on anti-cancer due to the difference of UGT isoforms in different cancer cells.
Department of Pharmacy, First Hospital Affiliated to Shihezi University, Shihezi, Xinjiang, 832002, China.|International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Xuejun
X
Zeng
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Jian
J
Shi
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Min
M
Zhao
Department of Pharmacy, First Hospital Affiliated to Shihezi University, Shihezi, Xinjiang, 832002, China.|International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Qingwei
Q
Chen
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Liping
L
Wang
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Huangyu
H
Jiang
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Feifei
F
Luo
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Lijun
L
Zhu
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Linlin
L
Lu
Department of Pharmacy, First Hospital Affiliated to Shihezi University, Shihezi, Xinjiang, 832002, China.
Xinchun
X
Wang
International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
Zhongqiu
Z
Liu
D047309:Flavones / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism*; D020719:Glucuronides / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047311:Luteolin / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D013237:Stereoisomerism; D000090264:UDP-Glucuronosyltransferase 1A9; D015854:Up-Regulation; D000099148:UGT1A1 Enzyme
D047309:Flavones; D005419:Flavonoids; D020719:Glucuronides; D014453:Glucuronosyltransferase; D047311:Luteolin; D000090264:UDP-Glucuronosyltransferase 1A9; D000099148:UGT1A1 Enzyme; C000715591:UGT1A9 protein, human; C110655:UDP-glucuronosyltransferase, UGT1A6; C007054:chrysoeriol; C039602:diosmetin