title: Lysine acetylsalicylate increases the safety of a paraquat formulation to freshwater primary producers: a case study with the microalga Chlorella vulgaris.
abstract: Large amounts of herbicides are presently used in the industrialized nations worldwide, with an inexorable burden to the environment, especially to aquatic ecosystems. Primary producers such as microalgae are of especial concern because they are vital for the input of energy into the ecosystem and for the maintenance of oxygen in water on which most of other marine life forms depend on. The herbicide paraquat (PQ) is known to cause inhibition of photosynthesis and irreversible damage to photosynthetic organisms through generation of reactive oxygen species in a light-dependent manner. Previous studies have led to the development of a new formulation of PQ containing lysine acetylsalicylate (LAS) as an antidote, which was shown to prevent the mammalian toxicity of PQ, while maintaining the herbicidal effect. However, the safety of this formulation to primary producers in relation to commercially available PQ formulations has hitherto not been established. Therefore, the aim of this study was to evaluate the toxicity of the PQ+LAS formulation in comparison with the PQ, using Chlorella vulgaris as a test organism. Effect criterion was the inhibition of microalgal population growth. Following a 96 h exposure to increasing concentrations of PQ, C. vulgaris growth was almost completely inhibited, an effect that was significantly prevented by LAS at the proportion used in the formulation (PQ+LAS) 1:2 (mol/mol), while the highest protection was achieved at the proportion of 1:8. In conclusion, the present work demonstrated that the new formulation with PQ+LAS has a reduced toxicity to C. vulgaris when compared to Gramoxone(®).
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, Department of Sciences, Advanced Institute of Health Sciences-North, CESPU, CRL, Rua Central de Gandra, 1317, 4585-116 Gandra, Portugal. Electronic address: mteresabaltazar@gmail.com.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Baltazar
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, Department of Sciences, Advanced Institute of Health Sciences-North, CESPU, CRL, Rua Central de Gandra, 1317, 4585-116 Gandra, Portugal; Department of Legal Medicine and Forensic Sciences, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal; CENCIFOR-Forensic Sciences Center, Largo da Sé Nova, 3000-213, Coimbra, Portugal.
authors.forename: Ricardo Jorge
authors.initials: RJ
authors.lastname: Dinis-Oliveira
authors.affiliation: CIIMAR Interdisciplinary Centre of Marine and Environmental Research, Laboratory of Ecotoxicology and Ecology, Rua dos Bragas, 289, 4050-123 Porto, Portugal; ICBAS-Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Populations Studies, Laboratory of Ecotoxicology, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Martins
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Maria de Lourdes
authors.initials: Mde L
authors.lastname: Bastos
authors.affiliation: CIAFEL, Faculty of Sports, University of Porto, Rua Dr. Plácido Costa, 91-4200-450 Porto, Portugal.
authors.forename: José Alberto
authors.initials: JA
authors.lastname: Duarte
authors.affiliation: CIIMAR Interdisciplinary Centre of Marine and Environmental Research, Laboratory of Ecotoxicology and Ecology, Rua dos Bragas, 289, 4050-123 Porto, Portugal; ICBAS-Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Populations Studies, Laboratory of Ecotoxicology, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Lúcia
authors.initials: L
authors.lastname: Guilhermino
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal. Electronic address: felixdc@ff.up.pt.
authors.forename: Félix
authors.initials: F
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D001241:Aspirin / Q000031:analogs & derivatives* / Q000494:pharmacology; D048408:Chlorella vulgaris / Q000187:drug effects*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D005618:Fresh Water; D008239:Lysine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010269:Paraquat / Q000633:toxicity*; D010788:Photosynthesis / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D016861:Cyclooxygenase Inhibitors; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D008239:Lysine; D010269:Paraquat; D001241:Aspirin; C010395:acetylsalicylic acid lysinate
keywords: Algae; Chlorella vulgaris.; Herbicides; Lysine acetylsalicylate; Paraquat