title: Aluminium sulfate exposure: A set of effects on hydrolases from brain, muscle and digestive tract of juvenile Nile tilapia (Oreochromis niloticus).
abstract: Aluminium is a major pollutant due to its constant disposal in aquatic environments through anthropogenic activities. The physiological effects of this metal in fish are still scarce in the literature. This study investigated the in vivo and in vitro effects of aluminium sulfate on the activity of enzymes from Nile tilapia (Oreochromis niloticus): brain acetylcholinesterase (AChE), muscle cholinesterases (AChE-like and BChE-like activities), pepsin, trypsin, chymotrypsin and amylase. Fish were in vivo exposed during 14days when the following experimental groups were assayed: control group (CG), exposure to Al2(SO4)3at 1μg·mL-1(G1) and 3μg·mL-1(G3) (concentrations compatible with the use of aluminium sulfate as coagulant in water treatment). In vitro exposure was performed using animals of CG treatment. Both in vivo and in vitro exposure increased cholinesterase activity in relation to controls. The highest cholinesterase activity was observed for muscle BChE-like enzyme in G3. In contrast, the digestive enzymes showed decreased activity in both in vivo and in vitro exposures. The highest inhibitory effect was observed for pepsin activity. The inhibition of serine proteases was also quantitatively analyzed in zymograms using pixel optical densitometry as area under the peaks (AUP) and integrated density (ID). These results suggest that the inhibition of digestive enzymes in combination with activation of cholinesterases in O. niloticus is a set of biochemical effects that evidence the presence of aluminium in the aquatic environment. Moreover, these enzymatic alterations may support further studies on physiological changes in this species with implications for its neurological and digestive metabolisms.
authors.affiliation: Laboratório de Enzimologia - LABENZ, Departamento de Bioquímica, and Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Cidade Universitária, 50670-420, Recife, PE, Brazil.
authors.forename: Vagne Melo
authors.initials: VM
authors.lastname: Oliveira
authors.affiliation: Laboratório de Enzimologia - LABENZ, Departamento de Bioquímica, and Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Cidade Universitária, 50670-420, Recife, PE, Brazil. Electronic address: caiodias2@hotmail.com.
authors.forename: Caio Rodrigo Dias
authors.initials: CR
authors.lastname: Assis
authors.affiliation: Laboratório de Enzimologia - LABENZ, Departamento de Bioquímica, and Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Cidade Universitária, 50670-420, Recife, PE, Brazil.
authors.forename: Helane Maria Silva
authors.initials: HM
authors.lastname: Costa
authors.affiliation: Unidade Acadêmica de Serra Talhada, Universidade Federal Rural de Pernambuco, Av. Gregório Ferraz Nogueira, S/N - José Tomé de Souza Ramos, 56909-535, Serra Talhada, PE, Brazil.
authors.forename: Raquel Pereira Freitas
authors.initials: RP
authors.lastname: Silva
authors.affiliation: Laboratório de Enzimologia - LABENZ, Departamento de Bioquímica, and Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Cidade Universitária, 50670-420, Recife, PE, Brazil; Unidade Acadêmica de Serra Talhada, Universidade Federal Rural de Pernambuco, Av. Gregório Ferraz Nogueira, S/N - José Tomé de Souza Ramos, 56909-535, Serra Talhada, PE, Brazil.
authors.forename: Juliana Ferreira
authors.initials: JF
authors.lastname: Santos
authors.affiliation: Laboratório de Enzimologia - LABENZ, Departamento de Bioquímica, and Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Cidade Universitária, 50670-420, Recife, PE, Brazil.
authors.forename: Luiz Bezerra
authors.initials: LB
authors.lastname: Carvalho
authors.affiliation: Laboratório de Enzimologia - LABENZ, Departamento de Bioquímica, and Laboratório de Imunopatologia Keizo Asami - LIKA, Universidade Federal de Pernambuco, Cidade Universitária, 50670-420, Recife, PE, Brazil. Electronic address: ransoube@uol.com.br.
authors.forename: Ranilson Souza
authors.initials: RS
authors.lastname: Bezerra
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000534:Alum Compounds / Q000633:toxicity*; D000681:Amylases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D002091:Butyrylcholinesterase / Q000378:metabolism; D023681:Cichlids / Q000378:metabolism*; D003720:Densitometry; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000633:toxicity; D029941:Fish Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000201:enzymology; D006867:Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009132:Muscles / Q000187:drug effects* / Q000201:enzymology; D010447:Peptide Hydrolases / Q000378:metabolism; D011480:Protease Inhibitors / Q000633:toxicity; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000534:Alum Compounds; D020536:Enzyme Activators; D029941:Fish Proteins; D011480:Protease Inhibitors; D014874:Water Pollutants, Chemical; C041524:aluminum sulfate; D006867:Hydrolases; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; D000681:Amylases; D010447:Peptide Hydrolases
keywords: Aluminium; Biomarker; Cholinesterase; Digestive enzyme; Pixel optical densitometry