Archives of Toxicology

, Volume 91, Issue 6, pp 2405–2423 | Cite as

Cytochrome P450-mediated metabolism of triclosan attenuates its cytotoxicity in hepatic cells

  • Yuanfeng Wu
  • Priyanka Chitranshi
  • Lucie Loukotková
  • Gonçalo Gamboa da Costa
  • Frederick A. Beland
  • Jie Zhang
  • Jia-Long FangEmail author
Organ Toxicity and Mechanisms


Triclosan is a widely used broad-spectrum anti-bacterial agent. The objectives of this study were to identify which cytochrome P450 (CYP) isoforms metabolize triclosan and to examine the effects of CYP-mediated metabolism on triclosan-induced cytotoxicity. A panel of HepG2-derived cell lines was established, each of which overexpressed a single CYP isoform, including CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2A7, CYP2A13, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP3A4, CYP3A5, CYP3A7, CYP4A11, and CYP4B1. The extent of triclosan metabolism by each CYP was assessed by reversed-phase high-performance liquid chromatography with online radiochemical detection. Seven isoforms were capable of metabolizing triclosan, with the order of activity being CYP1A2 > CYP2B6 > CYP2C19 > CYP2D6 ≈ CYP1B1 > CYP2C18 ≈ CYP1A1. The remaining 11 isoforms (CYP2A6, CYP2A7, CYP2A13, CYP2C8, CYP2C9, CYP2E1, CYP3A4, CYP3A5, CYP3A7, CYP4A11, and CYP4B1) had little or no activity toward triclosan. Three metabolites were detected: 2,4-dichlorophenol, 4-chlorocatechol, and 5′-hydroxytriclosan. Consistent with the in vitro screening data, triclosan was extensively metabolized in HepG2 cells overexpressing CYP1A2, CYP2B6, CYP2C19, CYP2D6, and CYP2C18, and these cells were much more resistant to triclosan-induced cytotoxicity compared to vector cells, suggesting that CYP-mediated metabolism of triclosan attenuated its cytotoxicity. In addition, 2,4-dichlorophenol and 4-chlorocatechol were less toxic than triclosan to HepG2/vector cells. Conjugation of triclosan, catalyzed by human glucuronosyltransferases (UGTs) and sulfotransferases (SULTs), also occurred in HepG2/CYP-overexpressing cells and primary human hepatocytes, with a greater extent of conjugation being associated with higher cell viability. Co-administration of triclosan with UGT or SULT inhibitors led to greater cytotoxicity in HepG2 cells and primary human hepatocytes, indicating that glucuronidation and sulfonation of triclosan are detoxification pathways. Among the 18 CYP-overexpressing cell lines, an inverse correlation was observed between cell viability and the level of triclosan in the culture medium. In conclusion, human CYP isoforms that metabolize triclosan were identified, and the metabolism of triclosan by CYPs, UGTs, and SULTs decreased its cytotoxicity in hepatic cells.


Triclosan Cytochrome P450 Glucuronidation Sulfonation Cytotoxicity 



Yuanfeng Wu and Priyanka Chitranshi were supported by an appointment to the Postgraduate Research in the Division of Biochemical Toxicology at the National Center for Toxicological Research administered by the Oak Ridge Institute for Science Education through an interagency agreement between the US Department of Energy and the US Food and Drug Administration.

Compliance with ethical standards

Conflict of interest

The authors declare that there are no conflicts of interest.

Supplementary material

204_2016_1893_MOESM1_ESM.docx (19 kb)
Supplementary material 1 (DOCX 18 kb)


  1. Achour B, Barber J, Rostami-Hodjegan A (2014) Expression of hepatic drug-metabolizing cytochrome P450 enzymes and their intercorrelations: a meta-analysis. Drug Metab Dispos 42(8):1349–1356. doi: 10.1124/dmd.114.058834 CrossRefPubMedGoogle Scholar
  2. Bagley DM, Lin YJ (2000) Clinical evidence for the lack of triclosan accumulation from daily use in dentifrices. Am J Dent 13(3):148–152PubMedGoogle Scholar
  3. Black JG, Howes D, Rutherford T (1975) Percutaneous absorption and metabolism of Irgasan® DP300. Toxicology 3(1):33–47CrossRefPubMedGoogle Scholar
  4. Braun Trapnell C, Klecker RW, Jamis-Dow C, Collins JM (1998) Glucuronidation of 3′-azido-3′-deoxythymidine (zidovudine) by human liver microsomes: relevance to clinical pharmacokinetic interactions with atovaquone, fluconazole, methadone, and valproic acid. Antimicrob Agents Chemother 42(7):1592–1596Google Scholar
  5. Calafat AM, Ye X, Wong L-Y, Reidy JA, Needham LL (2008) Urinary concentrations of triclosan in the U.S. population: 2003–2004. Environ Health Perspect 116(3):303–307. doi: 10.1289/ehp.10768 CrossRefPubMedGoogle Scholar
  6. Dayan AD (2007) Risk assessment of triclosan [Irgasan®] in human breast milk. Food Chem Toxicol 45(1):125–129. doi: 10.1016/j.fct.2006.08.009 CrossRefPubMedGoogle Scholar
  7. de Ruiter C, Bohle JF, de Jong GJ, Brinkman UAT, Frei RW (1988) Enhanced fluorescence detection of dansyl derivatives of phenolic compounds using a postcolumn photochemical reactor and application to chlorophenols in river water. Anal Chem 60(7):666–670CrossRefGoogle Scholar
  8. DeSalva SJ, Kong BM, Lin YJ (1989) Triclosan: a safety profile. Am J Dent 2:185–196PubMedGoogle Scholar
  9. Desta Z, Zhao X, Shin J-G, Flockhart DA (2002) Clinical significance of the cytochrome P450 2C19 genetic polymorphism. Clin Pharmacokinet 41(12):913–958. doi: 10.2165/00003088-200241120-00002 CrossRefPubMedGoogle Scholar
  10. Dykens JA, Jamieson JD, Marroquin LD et al (2008) In vitro assessment of mitochondrial dysfunction and cytotoxicity of nefazodone, trazodone, and buspirone. Toxicol Sci 103(2):335–345. doi: 10.1093/toxsci/kfn056 CrossRefPubMedGoogle Scholar
  11. Ethell BT, Anderson GD, Burchell B (2003) The effect of valproic acid on drug and steroid glucuronidation by expressed human UDP-glucuronosyltransferases. Biochem Pharmacol 65(9):1441–1449CrossRefPubMedGoogle Scholar
  12. Fang J-L, Stingley RL, Beland FA, Harrouk W, Lumpkins DL, Howard P (2010) Occurrence, efficacy, metabolism, and toxicity of triclosan. J Environ Sci Health C 28(3):147–171. doi: 10.1080/10590501.2010.504978 CrossRefGoogle Scholar
  13. Fang J-L, Vanlandingham MM, Juliar BE, Olson GR, Patton RE, Beland FA (2015) Dose-response assessment of the dermal toxicity of triclosan in B6C3F1 mice. Toxicol Res 4(4):867–877CrossRefGoogle Scholar
  14. Fang J-L, Vanlandingham M, Gamboa da Costa G, Beland FA (2016a) Absorption and metabolism of triclosan after application to the skin of B6C3F1 mice. Environ Toxicol 31(5):609–623. doi: 10.1002/tox.22074 PubMedGoogle Scholar
  15. Fang J-L, Wu Y, Gamboa da Costa G, Chen S, Chitranshi P, Beland FA (2016b) Human sulfotransferases enhance the cytotoxicity of tolvaptan. Toxicol Sci 150(1):27–39. doi: 10.1093/toxsci/kfv311 CrossRefPubMedGoogle Scholar
  16. Felser A, Blum K, Lindinger PW, Bouitbir J, Krӓhenbühl S (2013) Mechanisms of hepatocellular toxicity associated with dronedarone—a comparison to amiodarone. Toxicol Sci 131(2):480–490. doi: 10.1093/toxsci/kfs298 CrossRefPubMedGoogle Scholar
  17. Greer ML, Barber J, Eakins J, Kenna JG (2010) Cell based approaches for evaluation of drug-induced liver injury. Toxicology 268(3):125–131. doi: 10.1016/j.tox.2009.08.007 CrossRefPubMedGoogle Scholar
  18. Guengerich FP (2001) Common and uncommon cytochrome P450 reactions related to metabolism and chemical toxicity. Chem Res Toxicol 14(6):611–650CrossRefPubMedGoogle Scholar
  19. Gunes A, Dahl M-L (2008) Variation in CYP1A2 activity and its clinical implications: influence of environmental factors and genetic polymorphisms. Pharmacogenomics 9(5):625–637. doi: 10.2217/14622416.9.5.625 CrossRefPubMedGoogle Scholar
  20. Guo L, Dial S, Shi L et al (2011) Similarities and differences in the expression of drug-metabolizing enzymes between human hepatic cell lines and primary human hepatocytes. Drug Metab Dispos 39(3):528–538. doi: 10.1124/dmd.110.035873 CrossRefPubMedPubMedCentralGoogle Scholar
  21. Hovander L, Malmberg T, Athanasiadou M et al (2002) Identification of hydroxylated PCB metabolites and other phenolic halogenated pollutants in human blood plasma. Arch Environ Contam Toxicol 42(1):105–117. doi: 10.1007/s002440010298 CrossRefPubMedGoogle Scholar
  22. Juan-García A, Manyes L, Ruiz M-J, Font G (2013) Involvement of enniatins-induced cytotoxicity in human HepG2 cells. Toxicol Lett 218(2):166–173. doi: 10.1016/j.toxlet.2013.01.014 CrossRefPubMedGoogle Scholar
  23. Laine JE, Auriola S, Pasanen M, Juvonen RO (2009) Acetaminophen bioactivation by human cytochrome P450 enzymes and animal microsomes. Xenobiotica 39(1):11–21. doi: 10.1080/00498250802512830 CrossRefPubMedGoogle Scholar
  24. Moss T, Howes D, Williams FM (2000) Percutaneous penetration and dermal metabolism of triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether). Food Chem Toxicol 38(4):361–370CrossRefPubMedGoogle Scholar
  25. Nguyen KC, Willmore WG, Tayabali AF (2013) Cadmium telluride quantum dots cause oxidative stress leading to extrinsic and intrinsic apoptosis in hepatocellular carcinoma HepG2 cells. Toxicology 306:114–123. doi: 10.1016/j.tox.2013.02.010 CrossRefPubMedGoogle Scholar
  26. Ohno S, Nakajin S (2009) Determination of mRNA expression of human UDP-glucuronosyltransferases and application for localization in various human tissues by real-time reverse transcriptase-polymerase chain reaction. Drug Metab Dispos 37(1):32–40. doi: 10.1124/dmd.108.023598 CrossRefPubMedGoogle Scholar
  27. Riches Z, Stanley EL, Bloomer JC, Coughtrie MWH (2009) Quantitative evaluation of the expression and activity of five major sulfotransferases (SULTs) in human tissues: the SULT “pie”. Drug Metab Dispos 37(11):2255–2261. doi: 10.1124/dmd.109.028399 CrossRefPubMedPubMedCentralGoogle Scholar
  28. Rodricks JV, Swenberg JA, Borzelleca JF, Maronpot RR, Shipp AM (2010) Triclosan: a critical review of the experimental data and development of margins of safety for consumer products. Crit Rev Toxicol 40(5):422–484. doi: 10.3109/10408441003667514 CrossRefPubMedGoogle Scholar
  29. Sandborgh-Englund G, Adolfsson-Erici M, Odham G, Ekstrand J (2006) Pharmacokinetics of triclosan following oral ingestion in humans. J Toxicol Environ Health A 69(20):1861–1873. doi: 10.1080/15287390600631706 CrossRefPubMedGoogle Scholar
  30. Sim SC, Ingelman-Sundberg M (2010) The Human Cytochrome P450 (CYP) Allele Nomenclature website: a peer-reviewed database of CYP variants and their associated effects. Hum Genomics 4(4):278–281CrossRefPubMedPubMedCentralGoogle Scholar
  31. Tulp MTM, Sundström G, Martron LBJM, Hutzinger O (1979) Metabolism of chlorodiphenyl ethers and Irgasan® DP 300. Xenobiotica 9(2):65–77. doi: 10.3109/00498257909038708 CrossRefPubMedGoogle Scholar
  32. Wang L-Q, James MO (2006) Inhibition of sulfotransferases by xenobiotics. Curr Drug Metab 7(1):83–104CrossRefPubMedGoogle Scholar
  33. Wang L-Q, Falany CN, James MO (2004) Triclosan as a substrate and inhibitor of 3′-phosphoadenosine 5′-phosphosulfate-sulfotransferase and UDP-glucuronosyl transferase in human liver fractions. Drug Metab Dispos 32(10):1162–1169CrossRefPubMedGoogle Scholar
  34. Wu Y, Beland FA, Chen S, Fang J-L (2015) Extracellular signal-regulated kinases 1/2 and Akt contribute to triclosan-stimulated proliferation of JB6 Cl 41-5a cells. Arch Toxicol 89(8):1297–1311CrossRefPubMedGoogle Scholar
  35. Xiao Y, Xue X, Wu YF et al (2009) β-Naphthoflavone protects mice from aristolochic acid-I-induced acute kidney injury in a CYP1A dependent mechanism. Acta Pharmacol Sin 30(11):1559–1565. doi: 10.1038/aps.2009.156 CrossRefPubMedPubMedCentralGoogle Scholar
  36. Xue X, Gong L, Qi X et al (2011) Knockout of hepatic P450 reductase aggravates triptolide-induced toxicity. Toxicol Lett 205(1):47–54. doi: 10.1016/j.toxlet.2011.05.003 CrossRefPubMedGoogle Scholar
  37. Zanger UM, Schwab M (2013) Cytochrome P450 enzymes in drug metabolism: regulation of gene expression, enzyme activities, and impact of genetic variation. Pharmacol Ther 138(1):103–141. doi: 10.1016/j.pharmthera.2012.12.007 CrossRefPubMedGoogle Scholar
  38. Zhou S-F (2009) Polymorphism of human cytochrome P450 2D6 and its clinical significance. Part I. Clin Pharmacokinet 48(11):689–723. doi: 10.2165/11318030-000000000-00000 CrossRefPubMedGoogle Scholar
  39. Zhou S-F, Liu J-P, Chowbay B (2009) Polymorphism of human cytochrome P450 enzymes and its clinical impact. Drug Metab Rev 41(2):89–295. doi: 10.1080/03602530902843483 CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg (outside the USA) 2016

Authors and Affiliations

  • Yuanfeng Wu
    • 1
  • Priyanka Chitranshi
    • 1
  • Lucie Loukotková
    • 1
  • Gonçalo Gamboa da Costa
    • 1
  • Frederick A. Beland
    • 1
  • Jie Zhang
    • 2
  • Jia-Long Fang
    • 1
    Email author
  1. 1.Division of Biochemical Toxicology, National Center for Toxicological ResearchFood and Drug AdministrationJeffersonUSA
  2. 2.Division of Bioinformatics and Biostatistics, National Center for Toxicological ResearchFood and Drug AdministrationJeffersonUSA

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