Toxic Effects of Glyphosate-Based Herbicide on Melanopsis praemorsa

Abstract

In the present study, we determined the 24, 48, 72, and 96 h LC50 values for a glyphosate-based commercial herbicide (GBH) for the aquatic snail Melanopsis praemorsa. We examined subacute toxicity responses from M. praemorsa after 30-day exposure to 1/10, 1/5, and 1/2 of the 96 h LC50 value using several biochemical markers. Glutathione reductase (GR) and glutathione S-transferase (GST) activities were significantly inhibited when compared to control after 4 days of GBH exposure. On the twentieth day of exposure, GST and GR activities were inhibited in organisms exposed to both LC50/10 and LC50/5 compared to control. These results showed that chronic GBH exposure inhibited GST, an important detoxifying enzyme. GR, an important oxidative stress marker, was likely inhibited as a result of inhibition of the detoxification mechanism.