Ethidium bromide inhibits rat brain acetylcholinesterase activity in vitro

• Published in: Chemico-biological interactions Vol. 162; no. 2; pp. 121 - 127
• Main Authors: Mazzanti, Cinthia M., Spanevello, Roselia M., Obregon, Adriana, Pereira, Luciane B., Streher, Cristiane A., Ahmed, Mushtaq, Mazzanti, Alexandre, Graça, Dominguita L., Morsch, Vera M., Schetinger, Maria Rosa C.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 25.08.2006
• Subjects: Acetylcholinesterase; Acetylcholinesterase - chemistry; Acetylcholinesterase - metabolism; Analysis of Variance; Animals; Brain - enzymology; Catalysis - drug effects; Cerebellum - enzymology; Cerebral Cortex - enzymology; Cholinergic system; Cholinesterase Inhibitors - chemistry; Cholinesterase Inhibitors - pharmacology; Corpus Striatum - enzymology; Dose-Response Relationship, Drug; Ethidium - chemistry; Ethidium - pharmacology; Ethidium bromide; Hippocampus - enzymology; Kinetic analysis; Kinetics; Male; Rat; Rats; Rats, Wistar; Kinetic analysis; Cholinergic system; Ethidium bromide; Rat; Acetylcholinesterase
• ISSN: 0009-2797; 1872-7786
• DOI: 10.1016/j.cbi.2006.05.013

Ethidium bromide (EtBr), a fluorescent dark red compound and stain for double-stranded DNA and RNA was used to study acetylcholinesterase (AChE) activity in vitro together with kinetic parameters of this enzyme in the striatum (ST), hippocampus (HP), cerebral cortex (CC) and cerebellum (CB) of adult rats. AChE activity in vitro in the ST, HP, CC and CB was significantly reduced ( p < 0.05) in the presence of EtBr at concentrations of 0.00625, 0.0125, 0.025, 0.05 and 0.1 mM. For the analysis of the kinetic three concentrations of EtBr were tested (0.00625, 0.025 and 0.1 mM). An uncompetitive inhibition type was observed in the ST, HP and CC, whereas in the CB the inhibition type was mixed. These data indicate that EtBr should be considered a strong inhibitor of AChE activity demonstrating that there is an interaction between this compound and the cholinergic system.