Evaluation of Cocaine Effect on Endogenous Metabolites of HepG2 Cells Using Targeted Metabolomics.

Adamantios Krokos,Eleni Aggelidou,Olga Deda,Nikolaos Raikos,Georgios Theodoridis,Aristeidis Kritis,Helen Gika,Christina Virgiliou

doi:10.3390/molecules26154610

Adamantios Krokos, Eleni Aggelidou + Show 6 more

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https://doi.org/10.3390/molecules26154610

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Abstract

Cocaine toxicity has been a subject of study because cocaine is one of the most common and potent drugs of abuse. In the current study the effect of cocaine on human liver cancer cell line (HepG2) was assessed. Cocaine toxicity (IC50) on HepG2 cells was experimentally calculated using an XTT assay at 2.428 mM. The metabolic profile of HepG2 cells was further evaluated to investigate the cytotoxic activity of cocaine at 2 mM at three different time points. Cell medium and intracellular material samples were analyzed with a validated HILIC-MS/MS method for targeted metabolomics on an ACQUITY Amide column in gradient mode with detection on a triple quadrupole mass spectrometer in multiple reaction monitoring. About 106 hydrophilic metabolites from different metabolic pathways were monitored. Multivariate analysis clearly separated the studied groups (cocaine-treated and control samples) and revealed potential biomarkers in the extracellular and intracellular samples. A predominant effect of cocaine administration on alanine, aspartate, and glutamate metabolic pathway was observed. Moreover, taurine and hypotaurine metabolism were found to be affected in cocaine-treated cells. Targeted metabolomics managed to reveal metabolic changes upon cocaine administration, however deciphering the exact cocaine cytotoxic mechanism is still challenging.

Highlights

Methylbenzoylecognine, commonly known as cocaine is a major alkaloid of Erythroxylon coca Lam
Cocaine’s metabolic fates in humans include primarily a rapid hydrolytic metabolism to benzoylecgonine (BE) and ecgonine methyl ester (EME) and secondary to norcocaine, which in turn is metabolized to N-hydroxynorcocaine, norcocaine nitroxide, and to the hepatotoxic norcocaine nitrosonium ion [1,2]
The production of reactive oxygen species (ROS), the depressed mitochondrial respiration, and the diminishing antioxidant system due to the depletion of intracellular and mitochondrial glutathione have been linked to cocaine-induced in vivo and in vitro hepatotoxicity [3]

Summary

Introduction

Methylbenzoylecognine, commonly known as cocaine is a major alkaloid of Erythroxylon coca Lam. The production of reactive oxygen species (ROS), the depressed mitochondrial respiration, and the diminishing antioxidant system due to the depletion of intracellular and mitochondrial glutathione have been linked to cocaine-induced in vivo and in vitro hepatotoxicity [3]. The exact mechanism by which cocaine metabolites cause toxicity on target tissues and how this is linked to fatal conditions, are still under investigation [5]. For both human and animal models in multi-organs and systems such as heart, liver, kidney, and central nervous system (CNS), cocaine-induced toxic effects are linked to oxidative stress [6]

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