Combined effects of repeated administration of Bretmont Wipeout (glyphosate) and Ultrazin (atrazine) on testosterone, oxidative stress and sperm quality of Wistar rats.

Background: The potential toxicity resulting from the possible interactions of the herbicides, Ultrazin (atrazine, ATZ) and Bretmont Wipeout (glyphosate, GLY) (as commercialized in Nigeria), is not completely known. We therefore evaluated reproductive- and hepato-toxicity in rats co-exposed to ATZ and GLY.

Methods: Six weeks old male rats were exposed by gavage three times per week to ATZ (12.5 mg/kg) or GLY (5 mg/kg) alone or in combination (12.5 mg/kg ATZ + 5 mg/kg GLY) or vehicle (corn oil), for 52 days.

Results: ATZ and GLY impaired sperm quality but GLY has more adverse effect on sperm quality than ATZ. Testosterone level, sperm motility, sperm counts, live/dead ratio and the weight of the epididymis were lower in the GLY group compared to the ATZ group by 57%, 33%, 20%, 22% and 41% and higher by 109%, 76.7%, 39.6%, 32.3% and 100% respectively in the combine-exposure group (ATZ + GLY) compared to the GLY group. Oxidative stress and histopathological changes were also noticeable in the liver but not in the testis of GLY-treated animals, and the observed effects were more remarkable in the GLY group than the ATZ or the combined-exposure group. The combined effects of the active ingredients on testosterone level, sperm count and hepatic malondialdehyde (MDA) levels were also similar as when the commercial formulations were used.

Conclusion: There are therefore antagonistic interactions between the two toxicants on the toxicity endpoints investigated in this study and these effects are due to the active ingredients of both herbicides in the commercial formulations.