Environmental Toxicology and Pharmacology 28 (2009) 280–287 Contents lists available at ScienceDirect Environmental Toxicology and Pharmacology journal homepage: www.elsevier.com/locate/etap Antioxidant effect of alkynylselenoalcohol compounds on liver and brain of rats in vitro Carmine Inês Acker, Ricardo Brandão, Alisson Rodrigues Rosário, Cristina Wayne Nogueira ∗ Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, RS, Brazil article info Article history: Received 4 February 2009 Received in revised form 22 April 2009 Accepted 5 May 2009 Available online 14 May 2009 Keywords: Alkynylselenoalcohol Selenium Antioxidant Sodium nitroprusside Liver Brain abstract Alkynylselenoalcohol compounds were screened for in vitro antioxidant activity. Alkynylselenoalcohols (2a–2d) were tested against lipid and protein oxidation induced by sodium nitroprusside (SNP) in rat brain and liver. The inﬂuence of molecular structural modiﬁcations of alkynylselenoalcohols in their antiox- idant activity was investigated. The 1,1 ′ -diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and the interaction of alkynylselenoalcohols with iron were carried out. The results revealed that the antioxidant activity depends on their chemical structures. Compounds 2e (without hydroxyl group) and 3a (with a tellurium atom) presented better antioxidant proﬁles than 2b (with a hydroxyl group and selenium atom) against lipid and protein oxidation. Compound 1a (with a butyl group) did not mod- ify the effect of compound 2a (with a phenyl group) on lipid oxidation. Compounds 2e and 3a showed DPPH radical-scavenging activity. Compounds 2b, 2c and 3a inhibited isocitrate-mediated oxidation of Fe 2+ . Alkynylselenoalcohols demonstrated antioxidant effects and the modiﬁcations in the molecular structure of compound 2b improved its antioxidant potency. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Partially reduced derivatives of oxygen, which are produced in aerobic organisms as part of normal physiological and metabolic processes, are toxic species since they can oxidize numerous biomolecules leading to tissue injury and cell death (Morrissey and O’Brien, 1998). The balance between pro-oxidants and antioxidants is critical for the survival and functioning of aerobic organisms. An imbalance favoring pro-oxidants and/or disfavoring antioxidants, potentially leading to damage, has been called oxidative stress (Sies, 1985, 1986). It is known that oxidative damage of biological molecules such as lipoproteins, proteins and nucleotides by reactive oxygen species (ROS) can be associated with the development of diseases and degenerative processes, including inﬂammation, brain ischemia, mutagenesis, cancer, dementia and physiological aging (Ren et al., 2001). Moreover, oxidative stress also plays a central role in liver pathologies (Vitaglione et al., 2004). Thus, it is believed that exogenous antioxidant compounds could be employed to improve situations where the oxidative damage is involved. Evidence has been provided in the last two decades indicat- ing that organochalcogens are promising pharmacological agents and possess very interesting biological activities (Nogueira et al., 2004; Meotti et al., 2003). Several studies have reported a glu- ∗ Corresponding author. Tel.: +55 55 3220 8140; fax: +55 55 3220 8978. E-mail address: criswn@quimica.ufsm.br (C.W. Nogueira). tathione peroxidase (GPx)-mimetic activity of organochalcogen compounds (Parnham and Sies, 2000; Klotz et al., 2003; Nogueira et al., 2004). Organoselenides, among them diphenyl diselenide and ebselen, have been documented as promising pharmacologi- cal agents against a number of models of oxidative stress (Rossato et al., 2002; Meotti et al., 2004). Sodium nitroprusside (SNP) has been suggested to cause cyto- toxicity via release of cyanide and/or nitric oxide (Bates et al., 1991; Dawson et al., 1991; Rauhala et al., 1998). There are several stud- ies concerning the role of nitric oxide (NO) in the pathophysiology of strokes, traumas, seizures and Alzheimer’s, and Parkinson’s dis- eases (Castill et al., 2000; Prast and Philippou, 2001; Weisinger, 2001). It is known that light exposure promotes release of NO from SNP through a photodegradation process (Arnold et al., 1984; Singh et al., 1995), and data from the literature have demonstrated that after the release of NO, SNP or [NO–Fe–(CN) 5 ] 2- is converted to iron containing [(CN) 5 –Fe] 3- and [(CN) 4 –Fe] 2- species (Loiacono and Beart, 1992). After the release of NO, the iron moiety may react with SNP, which could lead to the formation of highly reactive oxy- gen species, such as hydroxyl radicals via the Fenton reaction (Graf et al., 1984). Therefore, the aim of this study was to evaluate the in vitro antioxidant activity of alkynylselenoalcohols against lipid and protein oxidation induced by sodium nitroprusside in rat brain and liver homogenates. The inﬂuence of molecular structure modiﬁcations on alkynylselenoalcohols against lipid and protein oxidation was investigated. We determined also the 1,1 ′ -diphenyl- 1382-6689/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.etap.2009.05.002