Impact of glyphosate and its formulation Roundup® on stallion spermatozoa

Glyphosate and its formulated product Roundup Transorb R® affect locomotor activity and reproductive and developmental parameters in Jenynsia lineata fish: An intergenerational study

Glyphosate is the most widely utilized herbicide worldwide due to its effectiveness in controlling agricultural weeds. However, its persistence in aquatic ecosystems has raised concerns about the well-being of non-target organisms such as fish. This study aimed to evaluate the effects of chronic exposure (21 days) to glyphosate or its formulated product Roundup Transorb R®, at an environmentally relevant concentration permitted by regulations in certain countries (65 μg/L of glyphosate), on the locomotor activity and reproductive success of the fish Jenynsia lineata, as well as on the morphology/development and locomotor activity of its offspring, as intergenerational effects. Neither the pure nor formulated herbicide altered the distance traveled and velocity of adult fish exposed to the herbicide (F0), but they negatively affected reproductive success, decreasing the percentage of positive response to the presence of the female, reducing the number of gravid females, causing abortions, and lowering offspring survival (F1). In the F1 generation, a decrease in weight and length was noted along with developmental abnormalities in both treatment groups (pure or formulated glyphosate), with the formulation causing more harm. Observed developmental abnormalities included muscle atrophy, ascites, pigmentary disorders, vertebral agenesis, spinal deviation, and exophthalmia. Furthermore, parental exposure to pure glyphosate led to an increase in the distance traveled and velocity of F1 (hyperlocomotion), whereas exposure to the formulated product resulted in a decrease in these behaviors (hypolocomotion) of F1. These findings highlight the toxic effects of glyphosate at very low concentrations, although varying between pure and formulated, and demonstrate the intergenerational consequences of herbicide exposure, underscoring the risk to the survival of fish offspring in glyphosate-contaminated environments.

Cytotoxicity Mechanisms of Eight Major Herbicide Active Ingredients in Comparison to Their Commercial Formulations

Commercial pesticide formulations contain co-formulants, which are generally considered as having no toxic effects in mammals. This study aims to compare the toxicity of 8 major herbicide active ingredients-namely glyphosate, dicamba, 2,4-D, fluroxypyr, quizalofop-p-ethyl, pendimethalin, propyzamide and metazachlor-with a typical commercial formulation of each active ingredient. Cytotoxicity and oxidative stress capability was assessed in human hepatoma HepG2 cells. Using an MTT assay, formulations of glyphosate (Roundup Probio), fluroxypyr (Hurler), quizalofop-p-ethyl (Targa Super) and dicamba (Hunter) were more toxic than the active ingredient alone. Metazachlor and its formulation Sultan had similar cytotoxicity profiles. Cytotoxicity profiles were comparable in immortalised human fibroblasts. Toxilight necrosis assays showed the formulation of metazachlor (Sultan50C) resulted in significant membrane disruption compared to the active ingredient. Generation of reactive oxygen species was detected for glyphosate, fluroxypyr, pendimethalin, quizalofop-p-ethyl, the formulation of 2,4-D (Anti-Liserons), and dicamba and its formulation Hunter. Further testing of quizalofop-p-ethyl and its formulation Targa Super in the ToxTracker assay system revealed that both products induced oxidative stress and an unfolded protein response. In conclusion, these results show that most herbicide formulations tested in this study are more toxic than their active ingredients in human tissue culture cell model systems. The results add to a growing body of evidence, which implies that commercial herbicide formulations and not just their active ingredients should be evaluated in regulatory risk assessment of pesticides.

The adverse impact of herbicide Roundup Ultra Plus in human spermatozoa plasma membrane is caused by its surfactant

The scarce research about the worldwide used glyphosate-based herbicide Roundup is controversial in human reproduction, especially spermatozoa. This study investigates the in vitro effect in human spermatozoa of Roundup Ultra Plus (RUP), its active ingredient glyphosate and its non-active, surfactant. Human spermatozoa were incubated (1 h, 37 °C) in presence/absence of RUP 0.01%, glyphosate, or equivalent surfactant concentration. Motility and sperm parameters were analyzed by C.A.S.A and flow cytometry, respectively. RUP significantly increases sperm plasma membrane lipid disorganization in a concentration-dependent manner while it decreases plasma membrane integrity. RUP significantly increases the death spermatozoa population after A23187-induced acrosome reaction, without affecting sperm viability, mitochondrial membrane potential, ROS content, acrosome membrane damage, phosphatidylserine exposure, A23187-induced acrosome reaction or GSK3 phosphorylation. RUP also significantly decreases motile and the a + b sperm populations. Interestingly, all sperm effects caused by RUP 0.01% are mimicked by its surfactant POEA at equivalent concentration. However, glyphosate does not affect any sperm parameter, even using 10-times higher concentration than the RUP 0.01% equivalent. RUP disturbs lipid organization and integrity of human sperm plasma membrane and reduces motility, without affecting viability or functional parameters. Importantly, RUP adverse effects in human spermatozoa are caused by the surfactant and no by glyphosate.