title: Growth inhibition of fungus Phycomyces blakesleeanus by anion channel inhibitors anthracene-9-carboxylic and niflumic acid attained through decrease in cellular respiration and energy metabolites.
abstract: Increasing resistance of fungal strains to known fungicides has prompted identification of new candidates for fungicides among substances previously used for other purposes. We have tested the effects of known anion channel inhibitors anthracene-9-carboxylic acid (A9C) and niflumic acid (NFA) on growth, energy metabolism and anionic current of mycelium of fungus Phycomyces blakesleeanus. Both inhibitors significantly decreased growth and respiration of mycelium, but complete inhibition was only achieved by 100 and 500 µM NFA for growth and respiration, respectively. A9C had no effect on respiration of human NCI-H460 cell line and very little effect on cucumber root sprout clippings, which nominates this inhibitor for further investigation as a potential new fungicide. Effects of A9C and NFA on respiration of isolated mitochondria of P. blakesleeanus were significantly smaller, which indicates that their inhibitory effect on respiration of mycelium is indirect. NMR spectroscopy showed that both A9C and NFA decrease the levels of ATP and polyphosphates in the mycelium of P. blakesleeanus, but only A9C caused intracellular acidification. Outwardly rectifying, fast inactivating instantaneous anionic current (ORIC) was also reduced to 33±5 and 21±3 % of its pre-treatment size by A9C and NFA, respectively, but only in the absence of ATP. It can be assumed from our results that the regulation of ORIC is tightly linked to cellular energy metabolism in P. blakesleeanus, and the decrease in ATP and polyphosphate levels could be a direct cause of growth inhibition.
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors.forename: Marina
authors.initials: M
authors.lastname: Stanić
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors.forename: Strahinja
authors.initials: S
authors.lastname: Križak
authors.affiliation: Institute for Biological Research 'Siniša Stanković', University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
authors.forename: Mirna
authors.initials: M
authors.lastname: Jovanović
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors.forename: Tanja
authors.initials: T
authors.lastname: Pajić
authors.affiliation: Institute for Biological Research 'Siniša Stanković', University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
authors.forename: Ana
authors.initials: A
authors.lastname: Ćirić
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors.forename: Milan
authors.initials: M
authors.lastname: Žižić
authors.affiliation: Institute of General and Physical Chemistry, Studentski trg 12-16, 11000 Belgrade, Serbia.
authors.forename: Joanna
authors.initials: J
authors.lastname: Zakrzewska
authors.affiliation: Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia.
authors.forename: Tijana Cvetić
authors.initials: TC
authors.lastname: Antić
authors.affiliation: Institute for Biological Research 'Siniša Stanković', University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
authors.forename: Nataša
authors.initials: N
authors.lastname: Todorović
authors.affiliation: Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Živić
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000873:Anthracenes / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D045744:Cell Line, Tumor; D019069:Cell Respiration / Q000187:drug effects*; D018553:Cucumis sativus / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D025282:Mycelium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D009544:Niflumic Acid / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D010800:Phycomyces / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D011122:Polyphosphates / Q000378:metabolism; D050994:Voltage-Dependent Anion Channels / Q000037:antagonists & inhibitors
chemical_list: D000873:Anthracenes; D000935:Antifungal Agents; D011122:Polyphosphates; D050994:Voltage-Dependent Anion Channels; D009544:Niflumic Acid; C010030:9-anthroic acid; D000255:Adenosine Triphosphate