Related Experiment Video

Updated: Aug 31, 2026

Continuous Fluorescence-Based Endonuclease-Coupled DNA Methylation Assay to Screen for DNA Methyltransferase Inhibitors
06:07

Continuous Fluorescence-Based Endonuclease-Coupled DNA Methylation Assay to Screen for DNA Methyltransferase Inhibitors

Published on: August 5, 2022

Activity of megazol, a trypanocidal nitroimidazole, is associated with DNA damage

Bertin Enanga1, Mark R Ariyanayagam, Mhairi L Stewart

  • 1Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.

Antimicrobial Agents and Chemotherapy
|September 25, 2003
PubMed

Insights

Megazol causes DNA damage in Trypanosoma brucei, as shown by hypersensitivity in DNA repair-deficient mutants. Resistance to megazol did not correlate with drug efflux or thiol levels.

Area of Science:

  • Parasitology
  • Molecular Biology
  • Drug Discovery

Background:

  • Trypanocidal drugs are crucial for treating neglected tropical diseases.
  • Understanding the mechanism of action of drugs like megazol is essential for developing new therapies.
  • DNA repair mechanisms in parasites like Trypanosoma brucei are potential targets for antimicrobial agents.

Purpose of the Study:

  • To investigate the mechanism of trypanocidal activity of megazol.
  • To determine if DNA damage is associated with megazol's activity.
  • To explore the basis of resistance to megazol in Trypanosoma brucei.

Main Methods:

  • Utilized DNA repair-deficient RAD51(-/-) Trypanosoma brucei mutants.
  • Selected for parasites resistant to megazol.
  • Assessed cross-resistance to other trypanocides.
  • Investigated potential correlations with drug efflux and intracellular thiol levels.

Main Results:

  • DNA repair-deficient Trypanosoma brucei mutants exhibited hypersensitivity to megazol, indicating DNA damage as a key mechanism.
  • Selected megazol-resistant parasites displayed modest cross-resistance to other trypanocides.
  • No correlation was found between megazol resistance and increased drug efflux or altered intracellular thiol concentrations.

Conclusions:

  • Megazol exerts its trypanocidal effect through the induction of DNA damage.
  • The development of resistance to megazol is not primarily mediated by common drug resistance mechanisms like efflux or thiol modification.
  • Further research into megazol's interaction with parasite DNA and repair pathways is warranted.

More Related Videos

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs10:44

Chemical Inactivation of the E3 Ubiquitin Ligase Cereblon by Pomalidomide-based Homo-PROTACs

Published on: May 15, 2019

Toxicological Assays for Testing Effects of an Epigenetic Drug on Development, Fecundity and Survivorship of Malaria Mosquitoes10:26

Toxicological Assays for Testing Effects of an Epigenetic Drug on Development, Fecundity and Survivorship of Malaria Mosquitoes

Published on: January 16, 2015

Related Concept Videos

Antiprotozoal Agents01:21

Antiprotozoal Agents

Leishmaniasis is a widespread parasitic disease caused by several Leishmania species. It affects millions of people each year and remains a major public health problem in endemic regions. First-line treatment relies on pentavalent antimonials, including meglumine antimoniate and sodium stibogluconate. Even so, how these drugs work has not been fully clear, especially their interaction with parasite-specific biochemical pathways. One key target is trypanothione reductase (TR), an enzyme that...
Bioactivation and Tissue Toxicity01:25

Bioactivation and Tissue Toxicity

Bioactivation is a metabolic process that transforms less reactive substances into highly reactive metabolites, initiating tissue toxicity. This transformation can lead to various toxic effects, including carcinogenesis and teratogenesis. Reactive metabolites are classified into two main types: electrophiles and free radicals.Electrophiles are electron-deficient species and are produced primarily by the enzyme cytochrome P-450 during the metabolism of compounds containing carbon, nitrogen, or...
Spontaneous and Induced Mutations01:30

Spontaneous and Induced Mutations

Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
Physical Properties of Amines01:26

Physical Properties of Amines

Amines with low molecular weight are usually gaseous at room temperature, while those with high molecular weight are liquid or solids in nature. Usually, low molecular weight amines have a rotten fish-like smell. Diamines typically have a pungent smell. For instance, cadaverine and putrescine, depicted in Figure 1, are two molecules responsible for decaying tissue.
Mutagenicity and Carcinogenicity01:25

Mutagenicity and Carcinogenicity

Mutagenicity and carcinogenicity refer to the ability of drugs to cause genetic defects and induce cancer, respectively. The International Agency for Research on Cancer (IARC) classifies agents into four groups based on their carcinogenic potential. Group 1 agents are known human carcinogens; group 2A agents are probably carcinogenic to humans; group 3 agents lack data to support their role in carcinogenesis; and group 4 includes agents for which data support that they are not likely to be...
Nucleotide Excision Repair01:38

Nucleotide Excision Repair

DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...