Synthesis and Cytotoxic Profile of 3,4-Methylenedioxymethamphetamine (“Ecstasy”) and Its Metabolites on Undifferentiated PC12 Cells:  A Putative Structure−Toxicity Relationship

Abstract

The toxicological and redox profiles of MDMA and its major metabolites (MDA, alpha-methyldopamine, N-methyl-alpha-methyldopamine, 6-hydroxy-alpha-methyldopamine, 3-methoxy-alpha-methyldopamine) were studied to establish a structure-toxicity relationship and determine their individual contribution to cell death induction by apoptosis and/or necrosis. The results of the comparative toxicity study, using undifferentiated PC12 cells, strongly suggest that the metabolites possessing a catecholic group are more toxic to the cells than MDMA and metabolites with at least one protected phenolic group. Redox studies reveal that an oxidative mechanism seems to play an important role in metabolite cytotoxicity. Nuclear features of apoptosis and/or necrosis show that most of the metabolites, particularly N-methyl-alpha-methyldopamine, induce cell death by apoptosis, largely accompanied by necrotic features. No significant differences were found between MDMA and the metabolites, concerning overall characteristics of cell death. These results may be useful to ascertain the contribution of metabolism in MDMA neurotoxicity molecular mechanisms.

Cellular and molecular mechanisms involved in the neurotoxicity of opioid and psychostimulant drugs

“…The catechol metabolite N-methyl-α-methyldopamine that results from O-demethylenation of MDMA and the catechol metabolites resulting from N-demethylation followed by O-demethylenation of MDMA, such as α-methyldopamine and 6-hydroxy-α-methyldopamine, were shown to be neurotoxic, and may be responsible by MDMA toxicity in catecholaminergic PC12 cells. In these cells, MDMA and its metabolites 3,4-methylenedioxyamphetamine (MDA) and 3-methoxy-α-methyldopamine were shown to be less toxic (Milhazes et al, 2006). In cortical neurons, MDMA and its metabolites N-methyl-α-methyldopamine and α-methyldopamine were also shown to be neurotoxic (Capela et al, 2006a).…”

“…MDMA also induces apoptotic features in PC12 cells (Milhazes et al, 2006) and in rat cortical neurons (Capela et al, 2006b). MDMA-induced apoptosis in rat cortical neurons seems to be dependent on 5-HT 2A receptor activation (Capela et al, 2006b).…”

Comparative potencies of 3,4‐methylenedioxymethamphetamine (MDMA) analogues as inhibitors of [3H]noradrenaline and [3H]5‐HT transport in mammalian cell lines

“…Two of these compounds, 2,5-dimethoxy-4-bromophenylethylamine (2CB) and 3,4-methylenedioxyphenyl-Nmethyl-2-butanamine (MBDB), have already been identified as contaminants in MDMA tablets, whereas 2,3-methylenedioxymethamphetamine (2,3-MDMA) has not been detected in either tablets or samples taken from drug users (Giroud et al, 1998;de Boer et al, 1999;Simonsen and Kaa, 2001;Vaiva et al, 2001a;Tanner-Smith, 2006). We have also synthesized the primary human MDMA metabolites, 4-hydroxy-3-methoxymethamphetamine (HMMA) and 4-hydroxy-3-methoxyamphetamine (HMA), for investigation in this study (de la Torre et al, 2004;Monks et al, 2004;Escobedo et al, 2005;Jones et al, 2005;Milhazes et al, 2006).…”

A mechanistic insight into 3,4-methylenedioxymethamphetamine (“ecstasy”)-mediated hepatotoxicity

“…Phase I MDMA metabolism involves two main routes (Figure 1): (1) chain conversion by N-dealkylation to 3,4-methylendioxyamphetamine (MDA) mainly by CYP1A2, CYP2B6, and CYP2C19 or (2) O-demethylenation of the ring leading to 3,4-dihydroxymethamphetamine (HHMA) and 3,4-dihydroxyamphetamine (HHA) mediated by CYP2D6, CYP3A4, and CYP2C19. The cytochromes responsible of catalyzing the O-demethylation of the ring yield the catechol-metabolites (HHMA, HHA), which are more cytotoxic than the parent compound, indicating that MDMA bioactivation occurs after the opening of the ring (Kreth et al 2000;Jones et al 2005;Milhazes et al 2006;Meyer et al 2008b;Antolino-Lobo et al 2010). These metabolites can be oxidized to the corresponding ortho-metabolites, which generates reactive oxygen species (ROS) and reactive nitrogen species (RNS) (Monks and Lau 1997).…”

“…These metabolites can be oxidized to the corresponding ortho-metabolites, which generates reactive oxygen species (ROS) and reactive nitrogen species (RNS) (Monks and Lau 1997). Moreover, the catecholmetabolites of MDMA can be further oxidized yielding aminochrome compounds, which can lead to the formation of dark-brown polymers of the melamine type and represent a later stage of the compromised cellular oxidation status (Kreth et al 2000;Jones et al 2005;Milhazes et al 2006).…”