Pesticide Activity Extends To The Brain

Widely used organophosphorus and thiocarbamate pesticides can affect numerous unintended targets in the brain, a study in mice reveals (J. Agric. Food Chem., DOI: 10.1021/jf101747r). Daniel K. Nomura of Scripps Research Institute and John E. Casida of the University of California, Berkeley, examined 29 insecticides, herbicides, and fungicides. Using a technique called activity-based protein profiling, they assessed the pesticides’ effects on neurologically important enzymes. They focused on identifying targets within the serine hydrolase family of enzymes, which is known to be affected by compounds with a chemical scaffold similar to that of the pesticides. Nomura and Casida found that several of the pesticides, including chlor­pyrifos, tribufos, and molinate, inhibited these enzymes in mice. Affected enzymes include monoacylglycerol lipase and fatty acid amide hydrolase, which regulate endocannabinoid function, and acyl protein thioesterases, which control formation of synaptic components known as dendritic spines. The researchers acknowledge that they used high doses of injected pesticides and recommend that further studies be carried out at lower dietary doses.