Metabonomic response in the bile of Odontesthes bonariensis (pisces: Atherinopsidae) expose to cypermethrin

CARRIQUIRIBORDE, P.; MARINO, D.J.; RONCO A.E.

Portland

Congreso; SETAC- North America 31th Annual Meeting; 2010

Society of Environmental Toxicology and Chemistry

Cypermethrin is a pyrethroid insecticide used for pest control in commercial agriculture and housekeeping. It is extremely toxic for fish and other aquatic organisms. Mechanism of action and detoxification has been well described for vertebrates, but not specific biomarker has been developed. A comprehensive profiling (“omic”) approach opened new possibilities to identify fingerprints of toxicity. In the present study, the global metabolic response (metabonomic) was assessed in the bile of the freshwater fish “pejerrey” (O. bonariensis) waterborne exposed to cypermethrin. Adult pejerrey were exposed either to 5 µg L-1 or solvent control (methanol) during 96 h using a static renewal system at 22ºC and 16:8 L/D photoperiod. Collected bile samples were extracted directly with diethyl ether, diluted in acidified water and extracted with diethyl ether, or directly analyzed without pretreatment. In the extracted samples both the aqueous and organic phase were assayed. Extracts or raw bile were analyzed by HPLC-MS using a C18 column, AcN/water mobile phase, and using either ESI or APCI sources in positive and negative mode. MS data were gathered, aligned, normalized, standardized and subtracted among treatments using dedicate software. Data statistical analysis was assessed using PCA and PLS. Identification of putative metabolite was conducted with the aid of metabolite databases. The maximum number of extracted ions was obtained using the ESI source in negative mode. The total number of ions obtained in the ether extract, aqueous phase and raw bile were 530, 500 and 1163 respectively. Comparison between extracted ions in the raw bile of expose and non-exposed fish showed 22 and 10 ions mere than 10-fold exalted or depressed, respectively. Within the exalted group, 11 corresponded to the (M-H)- of the Gluc-4OH-Cypermethrin or related fragments, and 2 to the SO4-4OH-Cypermethrin. SO4-4OH-Cypermethrin was not previously reported in the bile of fish by classical studies. Among the nine 10-fold depressed ions, was identified the putative taurine (absent in exposed fish) and dihydroxycoprostanoic acid (29-fold). The use of PCA and PLS analysis allowed discriminated expose and control fish on the basis of the bile metabolic response. The metabonomic response in the fish bile appears as a promissory biomarker to asses both, exposure and effect in feral fish exposed to cypermethrin.