Related Experiment Video

Updated: Jul 5, 2026

Unveiling Xenobiotic Transport and Effects in Isolated Mitochondria: Insights from Respirometric and Enzymatic Assays
08:03

Unveiling Xenobiotic Transport and Effects in Isolated Mitochondria: Insights from Respirometric and Enzymatic Assays

Published on: March 7, 2025

Aromatic antiepileptic drugs and mitochondrial toxicity: effects on mitochondria isolated from rat liver

N A G Santos1, W S G Medina, N M Martins

  • 1Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP, Avenida do Café s/n, 14040-903 Ribeirão Preto, SP, Brazil.

Toxicology in Vitro : an International Journal Published in Association with BIBRA
|April 25, 2008
PubMed

Insights

Aromatic antiepileptic drugs (AAED) can cause liver damage. Bioactivated metabolites of carbamazepine, phenytoin, and phenobarbital impair liver mitochondrial function, suggesting a role in drug-induced hepatotoxicity.

Area of Science:

  • Biochemistry
  • Hepatology
  • Toxicology

Background:

  • Idiosyncratic hepatotoxicity is a known complication of aromatic antiepileptic drugs (AAED).
  • Toxic arene oxide metabolites are implicated, but direct mitochondrial toxicity is also possible.
  • The impact of AAED on mitochondrial function remains uninvestigated.

Purpose of the Study:

  • To investigate the in vitro cytotoxic mechanisms of carbamazepine (CB), phenytoin (PT), and phenobarbital (PB) on hepatic mitochondrial function.
  • To assess the effects of both unaltered and bioactivated forms of these drugs.

Main Methods:

  • Used a murine hepatic microsomal system to generate bioactivated anticonvulsant metabolites.
  • Assessed mitochondrial respiration (states 3 and 4), respiratory control ratio (RCR), ATP synthesis, membrane potential, and calcium handling.
  • Evaluated drug effects on mitochondrial swelling.

Main Results:

  • Bioactivated drugs (CB-B, PB-B, PT-B) significantly impaired mitochondrial function, decreasing state 3 respiration, RCR, ATP synthesis, and membrane potential, while increasing state 4 respiration.
  • Bioactivated drugs also disrupted calcium uptake/release and inhibited calcium-induced swelling.
  • Unaltered phenobarbital (PB) affected respiration, ATP synthesis, and membrane potential, but not calcium handling or swelling.
  • The potency for inducing mitochondrial dysfunction followed the order: PT-B > PB-B > CB-B > PB.

Conclusions:

  • Results strongly suggest that mitochondrial toxicity plays a significant role in the pathogenesis of AAED-induced hepatotoxicity.
  • Bioactivation of AAED generates metabolites that directly damage hepatic mitochondria.
  • This study provides novel insights into the mechanisms underlying drug-induced liver injury from antiepileptic medications.

More Related Videos

Experimental Protocol for Detecting Mitochondrial Function in Hepatocytes Exposed to Organochlorine Pesticides08:39

Experimental Protocol for Detecting Mitochondrial Function in Hepatocytes Exposed to Organochlorine Pesticides

Published on: September 16, 2020

Determination of Mitochondrial Membrane Potential and Reactive Oxygen Species in Live Rat Cortical Neurons09:56

Determination of Mitochondrial Membrane Potential and Reactive Oxygen Species in Live Rat Cortical Neurons

Published on: May 23, 2011

Related Concept Videos

Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein01:20

Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein

Antiepileptic drugs, such as levetiracetam (Keppra) and brivaracetam (Briviact), have emerged as crucial tools in managing epilepsy. These medications exert their therapeutic effects by targeting the synaptic vesicle protein SV2A, a transmembrane glycoprotein primarily found in the brain.
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
The Electron Transport Chain01:30

The Electron Transport Chain

The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is coupled to ATP synthesis. This process is a significant source of energy in aerobic cells, and therefore inhibitors of the electron transport chain can be detrimental to the cell's metabolic processes.
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
Antiepileptic Drugs: GABAergic Pathway Potentiators01:18

Antiepileptic Drugs: GABAergic Pathway Potentiators

γ-aminobutyric acid or GABA, plays a pivotal role as an inhibitory neurotransmitter in the brain. GABA pathway potentiators, also known as GABAergic drugs, are a class of pharmaceutical agents designed to enhance the functioning of the GABAergic system. These medications primarily treat epilepsy, a neurological disorder characterized by recurrent seizures.
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
Antiepileptic Drugs: Glutamate Antagonists01:14

Antiepileptic Drugs: Glutamate Antagonists

Glutamate is a fundamental neurotransmitter in the central nervous system, playing a vital role in neuronal communication and various cognitive processes. Glutamate stands as the principal excitatory neurotransmitter in the brain. Its presence is crucial for the communication between neurons, underpinning essential processes such as synaptic transmission, neuronal excitability, and plasticity. These functions are vital for higher-order cognitive processes, including learning and memory. The...
Drug Toxicity: Dose-Dependent Reactions01:24

Drug Toxicity: Dose-Dependent Reactions

Drug toxicities can be stratified into pharmacological, pathological, or genotoxic based on their mechanisms. The incidence and severity of these toxicities generally increase with the drug's concentration in the body and exposure time.Pharmacological toxicity is evident when the therapeutic effects of drugs overshoot into adverse reactions in a predictable, dose-dependent manner. Central nervous system (CNS) depression from barbiturates is a classic example, with effects escalating from...