POLYCYCLIC AROMATIC-HYDROCARBONS INHIBIT THE ACTIVITY OF ACETYLCHOLINESTERASE PURIFIED FROM ELECTRIC-EEL

Polycyclic aromatic hydrocarbons (PAHs) are formed during the incomple te combustion of fossil fuels, wood anti municipal waste incineration, from internal combustion engines, and from various food cooking opera tions and are common environmental contaminants which have been detect ed in surface waters, sediments, soils, plants, and both rural and urb an air, In this sturdy, we have shown that, for the first time, in vit ro addition of PAHs dose-dependently inhibited the activity of acetylc holinesterase purified from electric eel in a competitive manner. The PAHs containing 3 or higher aromatic rings showed the highest inhibito ry effect with the IC50 values between 2 and 6 ppm. Among the PAHs tes ted, chrysene and pyrene exhibit the highest and lowest potency with I C50 values of 2.40+/-0.04 and 5.22+/-0.38 ppm, respectively. PAHs with lower number of aromatic rings, such as naphthalene, acenaphthylene a nd fluorene, and oxygenated PAHs, such as anthraquinone and xanthone, showed no or slight inhibition of the acetylcholinesterase activity. ( C) 1997 Academic Press.