Metabolites of the Roundup herbicide glyphosate linked to fatty liver disease in mice

Glyphosate, the plant-killing molecule in the widely used herbicide Roundup, is under perpetual scrutiny for its potential toxicity in mammals. Harm could derive from the chemical’s metabolites, such as glyoxylate, that are hypothesized to react with a protein’s functionally important amino acids, including cysteine. To test that idea, Daniel K. Nomura’s group at the University of California, Berkeley, charted differences in the proteomes of mice exposed to glyphosate compared with those of untreated mice (Cell Chem. Biol. 2017, DOI: 10.1016/j.chembiol.2016.12.013). Nomura’s team found that glyoxylate attached to several liver enzymes that are important for lipid metabolism and measured significant increases in liver fat deposits. They also conducted the experiment with acetochlor, another common herbicide, and found similar results (ACS Chem. Biol. 2017, DOI: 10.1021/acschembio.6b01001). “We don’t want to raise too much concern,” Nomura says, emphasizing that his study exposed mice to unnaturally high levels of herbicides. But the results are corroborated by another study recently published by Michael N. Antoniou of King’s College London and coworkers. That group exposed rats to extremely low doses of glyphosate in drinking water for two years and found disturbances in fat metabolism reminiscent of nonalcoholic fatty liver disease (Sci. Rep. 2017, DOI: 10.1038/srep39328). Nomura says that study “nicely reinforces” his group’s paper.