Short- and long-term exposure to methamidophos impairs spermatogenesis in mice

Methamidophos (MET) is a pesticide that has toxic properties, including effects on fertility. This study aimed to assess the joint action of treatment time and exposure to methamidophos on the male reproductive system. MET was orally administered to adult male Swiss mice at a dose of 0.004 mg.kg⁻¹ for 15 and 50 consecutive days. The following parameters were evaluated: weight of reproductive organs, spermatogenesis, sperm and Sertoli cell count, daily sperm production and sperm transit time. Short-term exposure to methamidophos induced a decrease in epididymal weight. The frequency of stages V–VI of spermatogenesis increased and the frequency of stage IX decreased. In the epididymis, sperm transit time (caput/corpus) was reduced and the relative sperm number (cauda) increased. Long-term exposure induced an increase in the frequencies of stages I–IV and V-VI and decreased the stages VII-VIII and IX. The number of Sertoli cells with evident nucleoli was reduced in both exposures. These results confirm the reproductive toxicity of MET.

Effects of subchronic exposure to Caryocar brasiliense peel ethanolic extract on male reproductive functions in Swiss mice

This study evaluated the effects of subchronic exposure to Caryocar brasiliense peel ethanolic extract (CBPE) on reproductive function in male Swiss mice. CBPE was administered orally for 28 days at doses of 75, 150 and 300 mg.kg^-1 bw; control group received saline. Fertility test was performed after 14 days of treatment and animals were euthanized after the end of the 28-day period for evaluation of the reproductive parameters. The tested doses produced no significant changes in plasma testosterone levels, daily sperm production, sperm concentration, sperm morphology or fertility rate. However, sperm transit time was reduced in the caput/corpus epididymis, the post-implantation loss rate increased and there were significant changes in spermatogenic dynamics at the highest dose. These results indicated that subchronic exposure to CBPE has low reproductive toxicity, but additional studies are recommended to provide evidence of long-term safety at high concentrations.