The herbicide glyphosate is a weak inhibitor of acetylcholinesterase in rats

The current work evaluated the inhibitory potency of the herbicide glyphosate (GLP) on acetylcholinesterase (AChE) activity in male and female rat tissues. The AChE activity in brain was higher (p < 0.05) than those observed in kidney (females: 2.2-fold; males: 1.9-fold), liver (females: 6-fold; males: 6.9-fold) and plasma (females: 14.7-fold; males: 25.3-fold). Enzyme activities were higher in presence of 10 mM GLP compared to those measured at an equimolar concentration of the potent AChE inhibitor dichlorvos (DDVP). Moreover, IC50s for GLP resulted between 6 × 104- and 6.8 × 105-fold higher than those observed for DDVP. In conclusion, GLP is a weak inhibitor of AChE in rats.