S-nitrosoglutathione-induced toxicity in Drosophila melanogaster: Delayed pupation and induced mild oxidative/nitrosative stress in eclosed flies Oleksandr V. Lozinsky a , Oleh V. Lushchak a , Natalia I. Kryshchuk a , Natalia Y. Shchypanska a , Anna H. Riabkina a , Stanislava V. Skarbek a , Ivan V. Maksymiv a , Janet M. Storey b , Kenneth B. Storey b , Volodymyr I. Lushchak a, ⁎ a Department of Biochemistry and Biotechnology, Precarpathian National University named after Vassyl Stefanyk, 57 Shevchenko Str., Ivano-Frankivsk 76025, Ukraine b Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario Canada K1S 5B6 abstract article info Article history: Received 6 June 2012 Received in revised form 13 August 2012 Accepted 14 August 2012 Available online 25 August 2012 Keywords: Aconitase Antioxidant enzymes Development Drosophila melanogaster Oxidative/nitrosative stress Reactive nitrogen species Reactive oxygen species S-nitrosoglutathione The toxicity of the nitric oxide donor S-nitrosoglutathione (GSNO) was tested on the Drosophila melanogaster model system. Fly larvae were raised on food supplemented with GSNO at concentrations of 1.0, 1.5 or 4.0 mM. Food supplementation with GSNO caused a developmental delay in the flies. Biochemical analyses of oxidative stress markers and activities of antioxidant and associated enzymes were carried out on 2-day-old flies that emerged from control larvae and larvae fed on food supplemented with GSNO. Larval ex- posure to GSNO resulted in lower activities of aconitase in both sexes and also lower activities of catalase and isocitrate dehydrogenase in adult males relative to the control cohort. Larval treatment with GSNO resulted in higher carbonyl protein content and higher activities of glucose-6-phosphate dehydrogenase in males and higher activities of superoxide dismutase and glutathione-S-transferase in both sexes. Among the parameters tested, aconitase activity and developmental end points may be useful early indicators of toxicity caused by GSNO. © 2012 Elsevier Inc. All rights reserved. 1. Introduction Oxidative stress arises when there is an imbalance between the production and elimination of reactive oxygen species (ROS) in favor of the former that is sufficient to disturb core and regulatory processes (Sies, 1991; Lushchak, 2011). Generation of reactive oxygen species (ROS) is an inevitable aspect of life under aerobic conditions, and ROS arise as by-products of various metabolic pathways and are also pro- duced by some specific systems under strict cellular controls (Lushchak, 2011). The deleterious effects of ROS are connected with oxidative mod- ification of virtually all cellular components, but at the same time, ROS are also used as signaling molecules in a variety of situations including cell differentiation and cell cycle progression and in response to extracellular stimuli (reviewed in Klatt and Lamas, 2000). Reactive oxygen species are eliminated via several mechanisms, both specific and non-specific. By analogy with oxidative stress, the term “nitrosative stress” is used to de- scribe excessive or deregulated formation of nitric oxide (•NO) and •NO-derived reactive nitrogen species (RNS) with diverse biological effects. Like ROS, •NO effects are also two-faced. On the one hand, •NO may limit oxidative damage by acting as a radical scavenger, but on the other hand, •NO and •NO-derived RNS may damage cells by numerous mechanisms (reviewed in Klatt and Lamas, 2000; Davis et al., 2001). To cope with oxidative stress, the cell has developed a number of defense strategies that act at levels of prevention of production, elim- ination, repair, and degradation of damaged molecules (Sies, 1991; Lushchak, 2011). Repair mechanisms that provide resistance to oxi- dative stress include various protein disulfide reductase enzymes as well as multifunctional DNA repair and thiol-reducing proteins such as the thioredoxin reductase/thioredoxin system (Nakamura et al., 1997). Antioxidant mechanisms include low-molecular-mass com- pounds such as GSH, radical-scavenging vitamins E and C, as well as high molecular mass antioxidants, such as ROS-metabolizing enzymes, including superoxide dismutase, peroxidases and others (Halliwell and Gutteridge, 1999). S-nitrosoglutathione (GSNO) is an endogenous S-nitrosothiol that plays a critical role in nitric oxide (•NO) signaling and is a source of bioavailable •NO. It can mimic the effects of endogenous •NO because •NO is released during GSNO decomposition. In basic research, GSNO has been used mainly to investigate different mechanisms triggered Comparative Biochemistry and Physiology, Part A 164 (2013) 162–170 Abbreviations: DTNB, 5,5′-dithio-bis (2-nitro) benzoic acid; EDTA, ethylene diamine tetraacetate; G6PDH, glucose-6-phosphate dehydrogenase; GSH/GSSG, reduced/oxidized glutathione; GSNO, S-nitrosoglutathione; GST, glutathione-S-transferase; ICDH, NADP-dependent isocitrate dehydrogenase; NADP/NADPH, oxidized/reduced nicotine amide adenine dinucleotide phosphate; PC, protein carbonyls; PMSF, phenylmethylsulfonyl fluoride; RNS, reactive nitrogen species; ROS, reactive oxygen species; SOD, superoxide dismutase; TrxR, thioredoxin reductase. ⁎ Corresponding author. Fax: +38 0342 596171. E-mail address: lushchak@pu.if.ua (V.I. Lushchak). 1095-6433/$ – see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.cbpa.2012.08.006 Contents lists available at SciVerse ScienceDirect Comparative Biochemistry and Physiology, Part A journal homepage: www.elsevier.com/locate/cbpa