Aquatic Toxicology 94 (2009) 177–185 Contents lists available at ScienceDirect Aquatic Toxicology journal homepage: www.elsevier.com/locate/aquatox Effects of environmental concentrations of the antiepilectic drug carbamazepine on biomarkers and cAMP-mediated cell signaling in the mussel Mytilus galloprovincialis Laura Martin-Diaz a,1 , Silvia Franzellitti b,1 , Sara Buratti b , Paola Valbonesi b , Antonio Capuzzo c , Elena Fabbri b,∗ a University of Cadiz, Department of Physical Chemistry, Polígono Río San Pedro s/n, 11510 Puerto Real, Spain b University of Bologna, Interdepartment Centre for Research in Environmental Sciences (CIRSA), via S. Alberto 163, 48123 Ravenna, Italy c University of Ferrara, Department of Biology and Evolution, via Borsari 46, 44100 Ferrara, Italy article info Article history: Received 15 May 2009 Received in revised form 25 June 2009 Accepted 27 June 2009 Keywords: Pharmaceuticals Biomarkers cAMP PKA MXR Mytilus galloprovincialis abstract Pharmaceuticals represent a diverse collection of thousands of bioactive chemicals used in human and veterinary medicine. The increased consumption, together with the recent development of more sensi- tive analytical techniques, has identified these as emerging contaminants in the aquatic environment. According to many investigations pharmaceuticals do not cause acute toxic effects in organisms when released in the environment. However, many independent studies agree that chronic exposure and more specific endpoints should be used in risk assessment of these compounds. We thus investigated the effects of exposure to environmentally relevant concentrations of the antiepileptic drug carbamazepine (CBZ) on Mediterranean mussels (Mytilus galloprovincialis) by considering the existing knowledge about the therapeutic and side effects of this drug on humans. To do so we analysed: (a) six consolidated biomark- ers related primarily to oxidative stress; (b) cAMP levels and protein kinase A (PKA) activities; (c) mRNA expression of MXR-related genes. MXR proteins are involved both in the cAMP pathway and in the pro- tective response of organisms towards xenobiotics. Mussels exposed to 0.1 or 10 g CBZ per liter water for 7 days showed a 60% and 80% reduction in haemocyte lysosome membrane stability, respectively. Moreover, increased neutral lipid and lipofuscin accumulation in the digestive gland, and lipid perox- idation in gills and mantle/gonads were observed. Also glutathione S-tranferase and catalase activities were increased in digestive gland and mantle, while no increase in primary DNA damage was observed. In agreement with the mode of action of CBZ in humans, exposure resulted in a significant reduction in cAMP levels and PKA activities in digestive gland, gills and mantle/gonads of mussels, and lowered the mRNA expression of genes encoding three different MXR-related transporters in the same tissues. Our data indicate that CBZ, at concentrations found in the environment, affects the Mediterranean mussel by acting on specific biochemical pathways that are evolutionarily conserved. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Pharmaceuticals represent a diverse collection of thousands of bioactive chemicals used in human and veterinary medicine. The increased consumption together with the recent develop- ment of more sensitive analytical techniques has lead to the identification of pharmaceuticals as emerging contaminants in the aquatic environment (Quinn et al., 2008). In fact, about one- hundred pharmaceuticals and their metabolites are reported in effluents and surface waters around the world (Gagnè et al., 2006). ∗ Corresponding author. Tel.: +39 0544 937311; fax: +39 0544 937411. E-mail address: elena.fabbri@unibo.it (E. Fabbri). 1 These authors equally contributed to the work performed. Amongst these compounds, non-prescription drugs (ibuprofen and aspirin), antibiotics (sulphonamides and macrolides), cholesterol- and lipid-regulating drugs (colifibrates and statins), -blockers (propranolol), neuroactive drugs (caffeine, carbamazepine, fluoxe- tine, and morphine), and miscellaneous medical contrasting agents are found in aquatic environments at concentrations in the ng to g per liter range (Daughton and Ternes, 1999; Fent et al., 2006). The recent discovery of pharmaceuticals in European, Japanese and North American groundwater, rivers and lakes has raised concern in both the regulatory and scientific arenas. To date legis- lation includes specific guidelines for assessing the environmental exposure to veterinary medical substances and risk assessment pro- cedures of the exposure to pharmaceuticals (2004/27/EU). These directives prescribe that a risk assessment should be part of the 0166-445X/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.aquatox.2009.06.015