title: The effects of thyme volatiles on the induction of DNA damage by the heterocyclic amine IQ and mitomycin C.
abstract: The leafy parts of thyme and its essential oil have been used in foods for its flavour, aroma and preservation for many years. In the present study the genotoxic potential of major compounds of thyme oil, i.e. thymol, carvacrol, and gamma-terpinene and of the methanolic extracts of thyme, were investigated in human lymphocytes by single-cell gel electrophoresis. Also, the effects of these substances on the induction of DNA damage by 2-amino-3-methylimidazo[4,5-f]-quinoline (IQ) and mitomycin C (MMC) were evaluated. No increase in DNA strand breakage was observed at thymol and gamma-terpinene concentrations below 0.1 mM, but at the higher concentration of 0.2 mM significant increases in DNA damage were seen. Thymol and gamma-terpinene significantly reduced the DNA strand breakage induced by IQ and MMC at the lower concentrations studied. Carvacrol, which is an isomer of thymol, seemed to protect lymphocytes from the genotoxic effects of IQ and MMC at non-toxic concentrations below 0.05 mM, but at the higher concentration of 0.1 mM carvacrol itself induced DNA damage. Also the constituents of the n-hexane and ethyl acetate fractions prepared from the concentrated aqueous methanolic extracts of Thymus spicata protected lymphocytes against IQ- and MMC-induced DNA damage in a concentration-dependent manner.
authors.affiliation: Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Hacettepe University, 06100 Ankara, Turkey.
authors.forename: Sevtap
authors.initials: S
authors.lastname: Aydin
authors.forename: A Ahmet
authors.initials: AA
authors.lastname: Başaran
authors.forename: Nurşen
authors.initials: N
authors.lastname: Başaran
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology; D002470:Cell Survival; D002478:Cells, Cultured; D020552:Comet Assay; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D016685:Mitomycin / Q000494:pharmacology*; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology*; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D000477:Alkylating Agents; D002273:Carcinogens; D009822:Oils, Volatile; D010938:Plant Oils; D011804:Quinolines; C029216:2-amino-3-methylimidazo(4,5-f)quinoline; D016685:Mitomycin; D004247:DNA