Study on mutagenesis induced by glyphosate in mice

Abstract: BACKGROUND AND AIM. To explore the glyphosate-induced mutagenesis in mice. MATERIALS AND METHODS. In micronucleus test(MNT), glyphosate was given twice via intragastric administration to different groups of mice at different concentrations(2 320 mg/kg, 1 160 mg/kg, 580 mg/kg) at a 24-hour interval. Mice were killed 6 hours after last treatment to determine the micronucleus rates of polychromatic erythrocytes(PCE) in the bone marrow. For sperm shape abnormality test, all mice were treated with glyphosate for 5 consecutive days at concentrations of 1 160 mg/kg, 290 mg/kg and 580 mg/kg. In the 1st and 4th week after the first treatment, half of mice were killed each time to regularly examine the sperm aberration rates, to count the total number of sperm, to weigh the testis and the epididymis,and to observe the change of organ coefficient. RESULTS. The micronucleus rate of 2 320 mg/kg group was significantly higher than that of negative control(P0.01).A dose-dependent response was observed between the treatment dose and the micronucleus rate(r=0.588,P0.01). One week after the first treatment, compared with negative control, the 580 mg/kg, 1 160 mg/kg groups both showed increasing rate of sperm aberration and decreased total number of sperm(P0.05,P0.01),while the 1 160 mg/kg group showed significantly decrease in epididymis weight and its coefficient(P0.05). Four weeks after the first treatment, by comparing to negative control, 1 160 mg/kg group showed increasing rate of sperm aberration and decreased total number of sperm(P0.05),as well as a decline in the weights of testis and epididymis. CONCLUSION. In this study, glyphosate showed reproductive toxicity in mice and certain mutagenesis.