PMID- 23454653
OWN - NLM
STAT- MEDLINE
DCOM- 20130515
LR  - 20131121
IS  - 1879-3169 (Electronic)
IS  - 0378-4274 (Linking)
VI  - 218
IP  - 3
DP  - 2013 Apr 26
TI  - In chemico evaluation of prohapten skin sensitizers: behavior of 
      2-methoxy-4-((1)(3)C)methylphenol in the peroxidase peptide reactivity assay (PPRA) 
      as an alternative to animal testing.
PG  - 266-72
LID - S0378-4274(13)00077-5 [pii]
LID - 10.1016/j.toxlet.2013.02.008 [doi]
AB  - In chemico methods, based on the assessment of a hapten's reactivity toward 
      peptides, have been proposed as alternative methods for the assessment of the 
      skin sensitizing potential of chemicals. However, even with these approaches 
      showing promise, a major drawback is the activation of prohaptens, i.e. molecules 
      needing a metabolic activation to become reactive and therefore sensitizing. 
      Recently, it has been proposed to couple an enzymatic activation step based on 
      horseradish peroxidase (HRP)/hydrogen peroxide to such peptide reactivity assays. 
      To evaluate this approach, the behavior of 2-methoxy-4-methylphenol (2M4MP), 
      reported as a moderate sensitizer according to the Local Lymph Node Assay (LLNA), 
      has been investigated in this assay. To follow the reaction with the peptides and 
      characterize more easily intermediates and adducts, the molecule was first (13)C 
      isotopically substituted at the most probable reactive position. When 2M4MP was 
      incubated with HRP/H2O2 in a mixture PBS (pH 7.4, 0.1M)/acetonitrile 2:1, two 
      main products were formed deriving from the formation of a quinone methide 2M4MQ 
      subsequently trapped by either H2O2 or H2O to form a benzylic hydroperoxide or 
      alcohol, respectively. When nucleophiles such as GSH or a peptide containing a 
      cysteine residue (Pep-Cys) were present in the reaction medium, the quinone 
      methide 2M4MQ was trapped by the more nucleophilic thiol function to form 
      thio-adducts. No modifications of 2M4MP were observed when the same reactions 
      were carried out without HRP confirming that the activation of the molecule was 
      enzyme related. Amino nucleophiles were shown to be far less reactive towards the 
      quinone methide 2M4MQ with only tiny formation of adducts with lysine or arginine 
      side chains. In addition we demonstrated that the same enzymatic activation could 
      also take place in a microemulsion based on sodium dodecyl 
      sulfate/tert-butanol/chloroform/buffer.
CI  - Copyright (c) 2013 Elsevier Ireland Ltd. All rights reserved.
FAU - Merckel, Fabien
AU  - Merckel F
AD  - Laboratoire de Dermatochimie, Institut de Chimie, CNRS and Universite de 
      Strasbourg, 4 rue Blaise Pascal, 67081 Strasbourg, France.
FAU - Gimenez-Arnau, Elena
AU  - Gimenez-Arnau E
FAU - Gerberick, G Frank
AU  - Gerberick GF
FAU - Lepoittevin, Jean-Pierre
AU  - Lepoittevin JP
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130227
PL  - Netherlands
TA  - Toxicol Lett
JT  - Toxicology letters
JID - 7709027
RN  - 0 (Acetonitriles)
RN  - 0 (Carbon Isotopes)
RN  - 0 (Cresols)
RN  - 0 (Emulsions)
RN  - 0 (Haptens)
RN  - 0 (Indolequinones)
RN  - 0 (Sulfhydryl Compounds)
RN  - 138230-21-4 (quinone methide)
RN  - BBX060AN9V (Hydrogen Peroxide)
RN  - EC 1.11.1.- (Horseradish Peroxidase)
RN  - GAN16C9B8O (Glutathione)
RN  - W9GW1KZG6N (creosol)
RN  - Z072SB282N (acetonitrile)
SB  - IM
MH  - Acetonitriles/chemistry
MH  - *Animal Testing Alternatives
MH  - Carbon Isotopes
MH  - Cresols/*chemistry/*immunology/toxicity
MH  - Dermatitis, Allergic Contact/*immunology
MH  - Emulsions
MH  - Glutathione/chemistry
MH  - Haptens/*chemistry/*immunology/toxicity
MH  - Horseradish Peroxidase/chemistry
MH  - Hydrogen Peroxide/chemistry
MH  - Hydrogen-Ion Concentration
MH  - Indolequinones/chemistry
MH  - Magnetic Resonance Spectroscopy
MH  - Models, Chemical
MH  - Molecular Structure
MH  - Structure-Activity Relationship
MH  - Sulfhydryl Compounds/chemistry
EDAT- 2013/03/05 06:00
MHDA- 2013/05/17 06:00
CRDT- 2013/03/05 06:00
PHST- 2012/09/07 00:00 [received]
PHST- 2013/02/18 00:00 [revised]
PHST- 2013/02/19 00:00 [accepted]
PHST- 2013/03/05 06:00 [entrez]
PHST- 2013/03/05 06:00 [pubmed]
PHST- 2013/05/17 06:00 [medline]
AID - S0378-4274(13)00077-5 [pii]
AID - 10.1016/j.toxlet.2013.02.008 [doi]
PST - ppublish
SO  - Toxicol Lett. 2013 Apr 26;218(3):266-72. doi: 10.1016/j.toxlet.2013.02.008. Epub 
      2013 Feb 27.