# Low Concentrations of Sulfoxaflor Do Not Adversely Affect mRNA Levels in Various Testicular Cells When Administered to Either Mature or Immature Mice

## TL;DR

Low doses of sulfoxaflor do not harm testicular cells in mice, as shown by unchanged gene expression and testis health.

## Contribution

This study is the first to show that low sulfoxaflor concentrations are not testicularly toxic in mice.

## Key findings

- Testis weights and histology were similar between sulfoxaflor-treated and control groups.
- mRNA levels of key testicular and pituitary markers were unaffected by sulfoxaflor treatment.
- No testicular toxicity was observed in mice, unlike in rats.

## Abstract

Sulfoxaflor, an insecticide, acts on nicotinic acetylcholine receptors. It has a functional group similar to that of neonicotinoid insecticides, which are testicular toxicants. Recently, the adverse effects of sulfoxaflor on the testes have been reported in rats. This study aimed to address the lack of reports on sulfoxaflor administration in mice and its effects on the testes. ICR mice (3- and 10-week-old) were treated ad libitum with two different concentrations (10 and 100 mg/kg) of sulfoxaflor for 4 and 8 weeks. Histological analysis and real-time reverse transcription polymerase chain reaction were performed. Testis weights relative to body weights in the sulfoxaflor groups showed no significant difference compared to the control group. Testicular tissue in the sulfoxaflor groups was unchanged compared to that in the control group. The sulfoxaflor-treated group showed no significant differences in the mRNA expression of luteinizing hormone and follicle-stimulating hormone in the pituitary gland compared to the control group. Furthermore, no significant differences were noted in the mRNA expression levels of various gene markers in the testes between the sulfoxaflor-treated and control groups. These markers include those related to Leydig cells, testosterone synthesis, Sertoli cells, proliferating cells, meiotic cells, pachytene spermatocytes, round spermatids, apoptotic cells, antioxidant enzymes, oxidative stress factors, and mitochondrial function. In contrast to findings in rats, which showed testicular toxicity, sulfoxaflor administration at low concentrations did not adversely affect intratesticular cells in either mature or immature mice at the doses and time points examined. In the future, we would like to conduct research on high concentrations of sulfoxaflor by changing the administration method.