title: Oxidative stress, uptake and bioconversion of 5-fluorouracil in algae.
abstract: Impact of cytostatic drug 5-fluorouracil (FU) and its metabolite 2-fluoro-3-alanine (FA) on green alga Scenedesmus quadricauda was studied. FA elevated fluorescence signal of reactive oxygen species (ROS) more pronouncedly than FU at 1 and 10 μM doses while both ROS and reactive nitrogen species (RNS/NO) increased more expressively in 100 μM FU treatment. Cellular damage staining (Acridine Orange and Calcofluor White) did no reveal substantial difference between FU and FA. Majority of free amino acids including proline was unaffected after 24h of exposure. FA depleted ascorbate peroxidase activity more than FU therefore ascorbate content (AsA) was less affected while FU stimulated glutathione reductase activity less than FA and therefore glutathione (GSH) was more depleted. Both compounds accumulated concentration-dependently with higher absolute FA amounts but FU conversion to FA was also detected. We subsequently influenced 100 μM FU- and FA-induced changes using known ROS (DTT - dithiothreitol) and RNS/NO (SNP - sodium nitroprusside and PTIO - 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) modulators and results showed that PTIO depleted NO and elevated ROS while the opposite was found after SNP and DTT addition. Changes of lipid peroxidation (using BODIPY staining) confirmed that FU and FA toxicity is related to alteration of ROS/RNS balance.
authors.affiliation: Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic. Electronic address: jozkovacik@yahoo.com.
authors.forename: Jozef
authors.initials: J
authors.lastname: Kováčik
authors.affiliation: Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic.
authors.forename: Bořivoj
authors.initials: B
authors.lastname: Klejdus
authors.affiliation: Department of Natural Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1/3, 612 42 Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Babula
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D001692:Biological Transport; D054750:Ecotoxicology; D005472:Fluorouracil / Q000009:adverse effects* / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D015227:Lipid Peroxidation; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D044444:Scenedesmus / Q000187:drug effects* / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000009:adverse effects / Q000378:metabolism
chemical_list: D000596:Amino Acids; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D009569:Nitric Oxide; D005978:Glutathione; D001205:Ascorbic Acid; D005472:Fluorouracil
keywords: Bioaccumulation; Confocal microscopy; Immunochemistry; Mass spectrometry; Nitric oxide