Search results for "Free radical damage to DNA"

showing 3 items of 3 documents

Intra- and extra-cellular DNA damage by harmine and 9-methyl-harmine

2014

It is known that b-carbolines are able to produce photosensitized damage in cell-free DNA, but there is little information on their effects on cellular DNA. Therefore, we have analyzed the DNA damage produced by harmine and 9-methyl-harmine under UVA irradiation in V79 cells, together with the associated generation of micronuclei and photocytotoxicity. The results indicate that the most frequent photoproducts generated in the cellular DNA are modified purines such as 8-oxo-7,8-dihydroguanine. Only relatively few single-strand breaks were observed. CPDs were absent, although they were generated in cell-free DNA irradiated under the same conditions. The overall extent of DNA damage in the cel…

Guanineb-carbolinesUltraviolet RaysDNA damageBiophysicsFree radical damage to DNACHO CellsMicronucleiBiologyPhototoxicitychemistry.chemical_compoundCricetulusHarmineCyclobutane pyrimidine photodimersCricetinaeAnimalsRadiology Nuclear Medicine and imagingPurine metabolismRadiationRadiological and Ultrasound TechnologyCell growthOtras Ciencias QuímicasCiencias QuímicasDNAHydrogen-Ion ConcentrationHarmineQuímica OrgánicaBiochemistrychemistryMicronucleus testBiophysicsPhotosensitizationPhototoxicityCIENCIAS NATURALES Y EXACTASDNADNA DamageJournal of Photochemistry and Photobiology B: Biology
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Photolysis of N-hydroxpyridinethiones: a new source of hydroxyl radicals for the direct damage of cell-free and cellular DNA.

1996

N-Hydroxypyridine-2-thione (2-HPT), known to release hydroxyl radicals on irradiation with visible light, and two related compounds, viz. N-hydroxypyridine-4-thione (4-HPT) and N-hydroxyacridine-9-thione (HAT), were tested for their potency to induce DNA damage in L1210 mouse leukemia cells and in isolated DNA from bacteriophage PM2. DNA single-strand breaks and modifications sensitive to various repair endonucleases (Fpg protein, endonuclease III, exonuclease III, T4 endonuclease V) were quantified. Illumination of cell-free DNA in the presence of 2-HPT and 4-HPT gave rise to damage profiles characteristic for hydroxyl radicals, i.e. single-strand breaks and the various endonuclease-sensit…

LightDNA damageCell SurvivalPyridinesRadicalFree radical damage to DNABiologychemistry.chemical_compoundEndonucleaseMiceSuperoxidesGeneticsTumor Cells CulturedAnimalsBacteriophagesLeukemia L1210chemistry.chemical_classificationExonuclease IIIReactive oxygen speciesEndodeoxyribonucleasesPhotolysisSinglet OxygenHydroxyl RadicalThionesDNAOxygenBiochemistrychemistryBiophysicsbiology.proteinAcridinesHydroxyl radicalReactive Oxygen SpeciesDNAResearch ArticleDNA Damage
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[39] DNA damage induced by ultraviolet and visible light and its wavelength dependence

2000

Publisher Summary DNA damage induced by solar radiation in mammalian cells consists largely of two types of modification: pyrimidine dimers and oxidative modifications. Pyrimidine dimmers that can be subdivided into cyclobutane pyrimidine dimmers, (CPDs) and (6-4) photoproducts are the characteristic and most abundant modifications after direct excitation of DNA, although they can also be formed indirectly by energy transfer from other excited molecules such as carbonyl compounds. Oxidative DNA damage, which includes various pyrimidine and purine modifications, sites of base loss (AP sites), and strand breaks, is generated in only low yield after direct excitation of DNA (except at very sho…

chemistry.chemical_compoundchemistryPyrimidineSinglet oxygenDNA damagemedicinePyrimidine dimerFree radical damage to DNAmedicine.disease_causePhotochemistryDNAUltravioletCyclobutane
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