Related Experiment Videos
DNA strand break by 2,5-dimethyl-4-hydroxy-3(2H)-furanone, a fragrant compound in various foodstuffs
K Hiramoto1, R Aso-o, H Ni-iyama
1Tokyo College of Pharmacy, Japan.
Abstract:
2,5-Dimethyl-4-hydroxy-3(2 H)-furanone (DMHF), produced by Maillard reaction of sugar/amino acid and found in various foodstuffs, showed mutagenicity to Salmonella typhimurium TA100 strain with and without S9 mix, and induced micronucleated mouse peripheral reticulocytes. DNA strand breaking activity of the compound at pH 7.4 increased with the increasing dose of the compound and with the increasing incubation time. The breaking activity was inhibited in the presence of superoxide dismutase, catalase, hydroxyl radical scavengers, spin trapping agents, thiol compounds and metal chelators, and also by removal of dissolved oxygen from the incubation mixture. Addition of Fe(III) ion to the incubation mixture enhanced the breaking activity. Incubation of DMHF with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) gave electron spin resonance signals characteristic to DMPO-OH adduct, indicating generation of hydroxyl radical. It was found that DMHF generated hydroxyl radical with an aid of a trace amount of metal ions, and induced DNA strand breaking. Mutagenicity and induction of micronucleated reticulocytes by DMHF may be caused as a result of DNA modification via hydroxyl radical.
Insights
2,5-Dimethyl-4-hydroxy-3(2 H)-furanone (DMHF), a food compound, is mutagenic and causes DNA damage. DMHF generates hydroxyl radicals, which are responsible for its mutagenic effects and DNA strand breaking activity.
Area of Science:
- Food Chemistry
- Toxicology
- Molecular Biology
Background:
- 2,5-Dimethyl-4-hydroxy-3(2 H)-furanone (DMHF) is a product of the Maillard reaction found in various foods.
- DMHF has demonstrated mutagenic potential in bacterial assays and induced genotoxicity in mammalian cells.
Purpose of the Study:
- To investigate the mechanism underlying the mutagenicity and DNA-damaging effects of DMHF.
- To determine if DMHF generates reactive oxygen species, specifically hydroxyl radicals.
Main Methods:
- Bacterial mutagenicity assays (Salmonella typhimurium TA100) with and without S9 mix.
- In vivo micronucleus test in mouse peripheral reticulocytes.
- In vitro DNA strand breaking assays at pH 7.4.
- Electron spin resonance (ESR) spectroscopy using DMPO as a spin trap.
- Inhibition studies with radical scavengers, metal chelators, and oxygen removal.
Main Results:
- DMHF exhibited mutagenicity and induced micronucleated reticulocytes.
- DMHF caused dose- and time-dependent DNA strand breaks.
- DNA breaking activity was attenuated by antioxidants, radical scavengers, metal chelators, and oxygen removal.
- ESR spectroscopy confirmed the generation of hydroxyl radicals (DMPO-OH adduct) from DMHF, particularly in the presence of trace metal ions.
- Fe(III) enhanced DMHF-induced DNA strand breaking.
Conclusions:
- DMHF induces DNA strand breaking and genotoxicity through the generation of hydroxyl radicals, potentially mediated by trace metal ions.
- The observed mutagenicity and clastogenicity of DMHF are likely attributed to hydroxyl radical-induced DNA modification.