Influence of CYP2D6 polymorphism on 3,4-methylenedioxymethamphetamine ('Ecstasy') cytotoxicity.
OBJECTIVE
Remarkable interindividual differences in 3,4-methylenedioxymethamphetamine ('Ecstasy')-mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 3,4-methylenedioxymethamphetamine.


METHODS
3,4-Methylenedioxymethamphetamine cytotoxicity was determined in V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low-activity alleles CYP2D6*2, *9, *10, and *17, as well as human CYP3A4. Metabolites of 3,4-methylenedioxymethamphetamine formed by the different cell lines were quantified by high-performance liquid chromatography/electrochemical detector.


RESULTS
Toxicity of 3,4-methylenedioxymethamphetamine was clearly increased in cells expressing CYP2D6*1 compared with the parental cells devoid of CYP-dependent enzymatic activity. Toxicity in V79 CYP2D6*1 cells was also higher than in V79 cell lines expressing the low-activity alleles CYP2D6*2, *9, *10, or *17. In contrast to CYP2D6, the CYP3A4 isoenzyme did not enhance 3,4-methylenedioxymethamphetamine toxicity. Formation of the oxidative 3,4-methylenedioxymethamphetamine metabolite N-methyl-alpha-methyldopamine was greatly enhanced in V79 cell line transfected with CYP2D6*1 compared to all other cell lines. The increase in the cytotoxic effects of 3,4-methylenedioxymethamphetamine observed in this cell line was therefore suspected to be a consequence of the production of this metabolite. This was further investigated by testing the cytotoxicity of N-methyl-alpha-methyldopamine to the control cell line. The results confirmed our hypothesis as the metabolite proved to be more than 100-fold more toxic than the parent compound 3,4-methylenedioxymethamphetamine.


CONCLUSIONS
CYP2D6*1 mediates 3,4-methylenedioxymethamphetamine toxicity via formation of N-methyl-alpha-methyldopamine. Therefore, it will be important to investigate whether CYP2D6 ultrarapid metabolizers are overrepresented in the cases of 3,4-methylenedioxymethamphetamine intoxications.
Carmo
Helena
H
REQUIMTE, Toxicology Department, Faculty of Pharmacy, University of Porto, Porto, Portugal. helenacarmo@ff.up.pt
Brulport
Marc
M
Hermes
Matthias
M
Oesch
Franz
F
Silva
Renata
R
Ferreira
Luísa M
LM
Branco
Paula S
PS
Boer
Douwe de
Dd
Remião
Fernando
F
Carvalho
Félix
F
Schön
Michael R
MR
Krebsfaenger
Niels
N
Doehmer
Johannes
J
Bastos
Maria de Lourdes
Mde L
Hengstler
Jan G
JG
D000483:Alleles; D000818:Animals; D002384:Catalysis; D002460:Cell Line; D006224:Cricetinae; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics* / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D003846:Deoxyepinephrine / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006213:Hallucinogens / Q000494:pharmacology / Q000633:toxicity*; D008954:Models, Biological; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000493:pharmacokinetics / Q000633:toxicity*; D010084:Oxidation-Reduction; D011110:Polymorphism, Genetic
D006213:Hallucinogens; C023492:alpha-methyldopamine; D003577:Cytochrome P-450 Enzyme System; C104464:CYP3A protein, human; D019389:Cytochrome P-450 CYP2D6; D051544:Cytochrome P-450 CYP3A; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D003846:Deoxyepinephrine