Abstract
Purpose. Dietary flavonoids, present in fruits, vegetables and beverages have been demonstrated to be protective in cancer. Recently, we showed that the flavonoid chrysin induced UDP-glucuronosyl- transferase (UGT) activity and expression in the human intestinal cell line Caco-2. In the present study, we determined the specific UGT isoform(s) induced and whether this induction facilitates glucuronidation and potential detoxification of the colon carcinogen 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-hydroxy-PhIP).
Methods. The induction was studied by immunoblot analysis with UGT isoform-specific antibodies, by Northern blot analysis and using quercetin as an isoform-specific catalytic probe. Glucuronidation of N-hydroxy-PhIP was characterized using both recombinant UGTs and control and chrysin-treated microsomes.
Results. Western blot analysis showed that pretreatment of Caco-2 cells with 25 μM chrysin induced UGT1A1 without affecting the expression of UGTs 1A6, 1A9 and 2B7. Northern blot analysis showed markedly increased expression of UGT1A1 mRNA after chrysin treatment. Similarly, glucuronidation of quercetin was greatly increased in a UGT1A1-specific way. The induction of UGT1A1 in the Caco-2 cells resulted in a 10-fold increase in the glucuronidation of N-hydroxy-PhIP.
Conclusion. Dietary flavonoid-mediated induction of intestinal UGT1A1 may be important for the glucuronidation and detoxification of colon and other carcinogens as well as for the presystemic metabolism of therapeutic drugs.
Similar content being viewed by others
REFERENCES
P. J. Bosma, J. Seppen, B. Goldhoorn, C. Bakker, R. P. J. Oude Elferink, J. R. Chowdhury, N. R. Chowdhury, and P. L. Jansen. Bilirubin UDP-glucuronosyltransferase 1 is the only relevant bilirubin glucuronidating isoform in man. J. Biol. Chem. 269:17960-17964 (1994).
M. D. Green, E. M. Oturu, and T. R. Tephly. Stable expression of a human liver UDP-glucuronosyltransferase (UGT2B15) with activity toward steroid and xenobiotic substrates. Drug Metab. Dispos. 22:799-805 (1994).
B. Burchell, C. H. Brierley, and D. Rance. Specificity of human UDP-glucuronosyltransferases and xenobiotic glucuronidation. Life Sci. 57:1819-1831 (1995).
R. H. Tukey, and C. P. Strassburg. Human UDP-glucuronosyltransferases: Metabolism, expression, and disease. Ann. Rev. Pharmacol. Toxicol. 40:581-616 (2000).
P. A. Münzel, S. Schmohl, H. Heel, K. Kälberer, B. S. Bock-Hennig, and K. W. Bock. Induction of human UDP glucuronosyltransferases (UGT1A6, UGT1A9, and UGT2B7) by t-butylhydroquinone and 2,3,7,8-tetrachlorodibenzo-p-dioxin in Caco-2 cells. Drug Metab. Dispos. 27:569-573 (1999).
F. K. Kessler and J. K. Ritter. Induction of a rat liver benzo[a-]pyrene-trans-7,8-dyhydrodiol glucuronidating activity by oltipraz and β-naphthoflavone. Carcinogenesis 18:107-114 (1997).
M. C. Canivenc-Lavier, M. F. Vernevaut, M. Totis, M. H. Siess, J. Magdalou, and M. Suschetet. Comparative effects of flavonoids and model inducers on drug-metabolizing enzymes in rat liver. Toxicology 114:19-27 (1996).
M. H. Siess, J. P. Mas, M. C. Canivenc-Lavier, and M. Suschetet. Time course of induction of rat hepatic drug-metabolizing enzyme activities following dietary administration of flavonoids. J. Toxicol. Envir. Health 49:481-496 (1996).
A. Galijatovic, U. K. Walle, and T. Walle. Induction of UDP-glucuronosyltransferase by the flavonoids chrysin and quercetin in Caco-2 cells. Pharm. Res. 17:21-26 (2000).
U. K. Laemmli. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227:680-685 (1970).
H. Towbin, T. Staehelin and J. Gordon. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: Procedure and some applications. Proc. Natl. Acad. Sci. USA 76: 4350-4354 (1979).
J. K. Ritter, F. K. Kessler, E. T. Thompson, A. D. Grove, D. J. Auyeung, and R. A. Fisher. Expression and inducibility of the human bilirubin UDP-glucuronosyltransferase UGT1A1 in liver and cultured primary hepatocytes: Evidence for both genetic and environmental influences. Hepatology 30:476-484 (1999).
A. Galijatovie, Y. Otake, U. K. Walle, and T. Walle. Extensive metabolism of the flavonoid chrysin by human Caco-2 and Hep G2 cells. Xenobiotica 29:1241-1256 (1999).
T. Walle, Y. Otake, A. Galijatovic, J. K. Ritter, and U. K Walle. Induction of UDP-glucuronosyltransferase (UGT) 1A1 by the flavonoid chrysin in the human hepatoma cell line Hep G2. Drug Metab. Dispos. 28:1077-1082 (2000).
K. H. Dingley, K. D. Curtis, S. Nowell, J. S. Felton, N. P. Lang, and K. W. Turteltaub. DNA and protein adduct formation in the colon and blood of humans after exposure to a dietary-relevant dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine. Cancer Epidemiol. Biomark. Prev. 8:507-512 (1999).
K. R. Kaderlik, G. J. Mulder, R. J. Turesky, N. P. Lang, C. H. Teitel, M. P. Chiarelli, and F. F. Kadlubar. Glucuronidation of N-hydroxy heterocyclic amines by human and rat liver microsomes. Carcinogenesis 15:1695-1701 (1994).
C. P. Strassburg, N. Nguyen, M. P. Manns, and R. H. Tukey. UDP-glucuronosyltransferase activity in human liver and colon. Gastroenterology 116:149-160 (1999).
X. Y. Sun, C. A. Plouzek, J. P. Henry, T. T. Y. Wang, and J. M. Phang. Increased UDP-glucuronosyltransferase activity and decreased prostate specific antigen production by biochanin A in prostate cancer cells. Cancer Res. 58:2379-2384 (1998).
M. F. Paine, and M. B. Fisher. Immunochemical identification of UGT isoforms in human small bowel and in Caco-2 cell monolayers. Biochem. Biophys. Res. Comm. 273:1053-1057 (2000).
K. W. Bock, T. Eckle, M. Ouzzine, and S. Fournel-Gigleux. Coordinate induction by antioxidants of UDP-glucuronosyltransferase UGT1A6 and the apical conjugate export pump MRP2 (multidrug resistance protein 2) in Caco-2 cells. Biochem. Pharmacol. 59:467-470 (2000).
S. A. Nowell, J. S. Massengill, S. Williams, A. Radominska-Pandya, T. R. Tephly, Z. Q. Cheng, C. P. Strassburg, R. H. Tukey, S. L. MacLeod, N. P. Lang, and F. F. Kadlubar. Glucuronidation of 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine by human microsomal UDP-glucuronosyltransferases: Identification of specific UGT1A family isoforms involved. Carcinogenesis 20:1107-1114 (1999).
M. A. Malfatti and J. S. Felton. The glucuronidation of the cooked-food carcinogen intermediate N-OH-PhIP by human UDP-glucuronosyltransferases. Proceed. Am. Assoc. Cancer Res. 41:835-836 (2000).
M. A. Malfatti, K. S. Kulp, M. G. Knize, C. Davis, J. P. Massengill, S. Williams, S. Nowell, S. MacLeod, K. H. Dingley, K. W. Turteltaub, N. P. Lang and J. S. Felton. The identification of [2-14C]2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine metabolites in humans. Carcinogenesis 20:705-713 (1999).
U. K. Walle, A. Galijatovic, and T. Walle. Transport of the flavonoid chrysin and its conjugated metabolites by the human intestinal cell line Caco-2. Biochem. Pharmacol. 58:431-438 (1999).
T. Ebner, R. P. Remmel, and B. Burchell. Human bilirubin UDP-glucuronosyltransferase catalyzes the glucuronidation of ethinylestradiol. Mol. Pharmacol. 43:649-654 (1993).
L. Iyer, C. D. King, P. F. Whitington, M. D. Green, S. K. Roy, T. R. Tephly, B. L. Coffman, and M. J. Ratain. Genetic predisposition to the metabolism of irinotecan (CPT-11): Role of uridine diphosphate glucuronosyltransferase isoform 1A1 in the glucuronidation of its active metabolite (SN-38) in human liver microsomes. J. Clin. Invest. 101:847-854 (1998).
P. B. Watkins. The barrier function of CYP3A4 and P-glycoprotein in the small bowel. Advan. Drug Deliv. Rev. 27:161-170 (1997).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Galijatovic, A., Otake, Y., Walle, U.K. et al. Induction of UDP-Glucuronosyltransferase UGT1A1 by the Flavonoid Chrysin in Caco-2 Cells—Potential Role in Carcinogen Bioinactivation. Pharm Res 18, 374–379 (2001). https://doi.org/10.1023/A:1011019417236
Issue Date:
DOI: https://doi.org/10.1023/A:1011019417236