Molecular and Cellular Mechanisms of Ecstasy-Induced Neurotoxicity: An Overview

Summary

MDMA (ecstasy) is a widely abused hallucinogenic drug that can damage nerve cells in both animals and humans. In rats and some mouse strains, it destroys serotonin-producing nerve endings and causes broader brain damage in areas like the cortex, hippocampus, and striatum. In human users, reduced serotonin markers correlate with lasting memory and learning problems. The neurotoxicity involves multiple factors: hyperthermia, metabolism by monoamine oxidase, dopamine oxidation, serotonin transporter activity, nitric oxide and peroxynitrite formation, glutamate excitotoxicity, serotonin 2A receptor activation, and toxic metabolites. This review summarizes the history, pharmacology, metabolism, and cellular/molecular mechanisms of MDMA neurotoxicity to aid development of treatments for long-term psychiatric complications.

Study at a glance

Abstract

“Ecstasy” [(±)-3,4-methylenedioxymethamphetamine, MDMA, XTC, X, E] is a psychoactive recreational hallucinogenic substance and a major worldwide drug of abuse. Several reports raised the concern that MDMA has the ability to induce neurotoxic effects both in laboratory animals and humans. Despite more than two decades of research, the mechanisms by which MDMA is neurotoxic are still to be fully elucidated. MDMA induces serotonergic terminal loss in rats and also in some mice strains, but also a broader neuronal degeneration throughout several brain areas such as the cortex, hippocampus, and striatum. Meanwhile, in human “ecstasy” abusers, there are evidences for deficits in seronergic biochemical markers, which correlate with long-term impairments in memory and learning. There are several factors that contribute to MDMA-induced neurotoxicity, namely, hyperthermia, monoamine oxidase metabolism of dopamine and serotonin, dopamine oxidation, the serotonin transporter action, nitric oxide, and the formation of peroxinitrite, glutamate excitotoxicity, serotonin 2A receptor agonism, and, importantly, the formation of MDMA neurotoxic metabolites. The present review covered the following topics: history and epidemiology, pharmacological mechanisms, metabolic pathways and the influence of isoenzyme genetic polymorphisms, as well as the acute effects of MDMA in laboratory animals and humans, with a special focus on MDMA-induced neurotoxic effects at the cellular and molecular level. The main aim of this review was to contribute to the understanding of the cellular and molecular mechanisms involved in MDMA neurotoxicity, which can help in the development of therapeutic approaches to prevent or treat the long-term neuropsychiatric complications of MDMA abuse in humans.