title: Interaction of diazinon with DNA and the protective role of selenium in DNA damage.
abstract: The interaction of native calf thymus DNA with Diazinon, an organophophorus insecticide, in HEPES buffer at neutral pH, was monitored by UV absorption spectrophotometry, circular dichroism (CD), electrochemical technique, and fluorescence spectroscopy. UV spectra showed hyperchromicity and blue shift with the increase of Diazinon concentration. Fluorescence spectroscopy results indicated that the probable quenching mechanism of DNA-ethidium bromide (EB) fluorescence by Diazinon is a dynamic quenching procedure, because the Stern-Volmer quenching constant (K(SV)) increased with the temperature rising. Unchanging of the CD signal around 280 nm with increasing ratio of Diazinon to DNA is an important evidence for non-intercalative-binding mode of Diazinon with DNA. Stoichiometry measurement of the DNA-nDiazinon indicated that a stable 1:2 complex of DNA-Diazinon was formed under the selected conditions. The electrochemical study of the Diazinon-DNA interaction was carried out by incubation of DNA with Diazinon in the presence of varying amounts of selenium (Se). This technique revealed that Se is able to diminish the DNA damage effect of Diazinon.
authors.affiliation: Department of Chemistry and Sensor and Biosensor Research Center (SBRC), Faculty of Science, Razi University, Kermanshah, Iran. kashanian_s@yahoo.com
authors.forename: Soheila
authors.initials: S
authors.lastname: Kashanian
authors.forename: Mohammad Bagher
authors.initials: MB
authors.lastname: Gholivand
authors.forename: Farhad
authors.initials: F
authors.lastname: Ahmadi
authors.forename: Hadi
authors.initials: H
authors.lastname: Ravan
mesh_terms: D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000187:drug effects*; D004249:DNA Damage; D003976:Diazinon / Q000633:toxicity*; D004563:Electrochemistry; D004996:Ethidium; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D007306:Insecticides / Q000633:toxicity*; D012643:Selenium / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D005456:Fluorescent Dyes; D007306:Insecticides; D004247:DNA; D004996:Ethidium; D012643:Selenium; D003976:Diazinon