Proteomic evaluation of potentiated sulfa treatment on gilthead sea bream (Sparus aurata L.) liver

Potentiated sulfa drugs are a combination of sulfonamide and pyrimidine potentiators. They are currently used against fish bacterial pathogens in Mediterranean marine fish farming. The present work aimed studying the potential hepatotoxicity of a combination of sulfadiazine (SDZ) and trimethoprim (TMP) in gilthead sea bream juveniles after oral administration, at the recommended ratio of 5: 1 (SDZ/TMP), equivalent to a dose of 30 mg kg(-1) fish day(-1), for 10 days at 19 degrees C temperature. Electrophoresis (DIGE) technology coupled with MS was used to identify possible markers of hepatotoxicity of this treatment. The results obtained show significant changes in the expression of 41 proteins by treatment (p <= 0.02). Among these proteins, 14 increased in abundance, and 27 decreased with respect to the control group. Proteins showing differential expression with respect to the control were identified by PMF and/or LC-MS/MS and database research. Proteins like apolipoprotein A-I and fatty acid binding protein (lipid metabolism and transport, and antioxidant role), phosphoglucomutase 1 (carbohydrate metabolism), elongation factor 1-alpha (protein biosynthesis and antioxidant role), mitochondrial aldehyde dehydrogenase (oxidation regulation activity and antioxidant role) and ypbc-32-D06 (aminotransferases), were differentially expressed in treated fish. These proteins have not been associated before with potentiated sulfa effect in farmed fish. However, they are frequently found differentially expressed as a characteristic cellular/tissue stress response under different experimental conditions, making difficult their use as specific biomarkers for this treatment. (C) 2012 Elsevier B.V. All rights reserved.