Richard, S., Moslemi, S., Sipahutar, H., Benachour, N., & Seralini, G. E. (2005). Differential effects of glyphosate and roundup on human placental cells and aromatase. Environmental health perspectives. https://doi.org/10.1289/ehp.7728
Richard S, Moslemi S, Sipahutar H, Benachour N, Seralini GE. Differential effects of glyphosate and roundup on human placental cells and aromatase. Environmental health perspectives. 2005. doi:10.1289/ehp.7728
Richard, S., et al. "Differential effects of glyphosate and roundup on human placental cells and aromatase." Environmental health perspectives, 2005.
Roundup was more toxic than glyphosate to human placental cells
Lab experiments on a human placental cell line found that Roundup was more toxic to human placental cells than glyphosate alone. At lower, nontoxic levels, Roundup reduced aromatase activity in these cells after 18 hours. Aromatase makes estrogen. Samples from human placenta and horse testis pointed the same way.
Key Findings
Roundup was more toxic to JEG3 placental cells. The median lethal dose was approximately 1.8 times lower than that of glyphosate, and viability fell at concentrations 10 times lower than agricultural use.
After 18 hr, acidity of the solutions reduced cell viability only 23%. Acidity could not alone explain the 90% reduction observed at the highest concentration tested.
In JEG3 cells at nontoxic concentrations, estrogen synthesis rose about 40% after 1 hr, but only with Roundup. After 18 hr, Roundup clearly inhibited aromatase activity, and mRNA levels were decreased.
Glyphosate was inefficient alone on aromatase in cells under these conditions. Glyphosate inhibited aromatase activity when minute dilutions of Roundup brought the adjuvants into the solution.
Microsomes from human placenta and horse testis responded equivalently to Roundup. A type II spectrum on purified equine aromatase indicated an interaction with the active site.
Interpretation
This is a laboratory (in vitro) study. The authors used JEG3, a cell line from a placental cancer. They also used microsomes (isolated membrane fractions) from human placentas and horse testis, plus purified horse enzyme. The authors conclude that Roundup may be considered a potential endocrine disruptor. They suggest its adjuvants (added ingredients) enhance glyphosate bioavailability. The authors note that the effects of these concentrations on the body can be questioned, and that exposure in the body may last longer than the experiments did.
RRM Context
Restorative reproductive medicine looks for the cause of reproductive problems. The paper describes aromatase as the enzyme that turns androgens into estrogens. It links the enzyme to egg and sperm formation, reproduction and sex differentiation. A compound acting on aromatase belongs in that search for both partners. The authors also point to a reported harmful effect of glyphosate on semen quality in rabbits.
Our editorial summary of this paper, not the article's abstract.
Abstract
Roundup is a glyphosate-based herbicide used worldwide, including on most genetically modified plants that have been designed to tolerate it. Its residues may thus enter the food chain, and glyphosate is found as a contaminant in rivers. Some agricultural workers using glyphosate have pregnancy problems, but its mechanism of action in mammals is questioned. Here we show that glyphosate is toxic to human placental JEG3 cells within 18 hr with concentrations lower than those found with agricultural use, and this effect increases with concentration and time or in the presence of Roundup adjuvants. Surprisingly, Roundup is always more toxic than its active ingredient. We tested the effects of glyphosate and Roundup at lower nontoxic concentrations on aromatase, the enzyme responsible for estrogen synthesis. The glyphosate-based herbicide disrupts aromatase activity and mRNA levels and interacts with the active site of the purified enzyme, but the effects of glyphosate are facilitated by the Roundup formulation in microsomes or in cell culture. We conclude that endocrine and toxic effects of Roundup, not just glyphosate, can be observed in mammals. We suggest that the presence of Roundup adjuvants enhances glyphosate bioavailability and/or bioaccumulation.
