Metabolomics-based study on effects of flurochloridone on testicular inflammatory injury in mice and its mechanism

Objective To investigate the effects of flurochloridone (FLC) exposure on testicular metabolism and inflammation in mice using metabolomics technology.

Methods Male C57BL/6 mice aged 6 to 8 weeks were randomly divided into a control group and FLC-exposed groups with doses of 3, 15, 75, and 375 mg/(kg·d). Hematoxylin-eosin(HE) staining was used to observe pathological changes in mouse testes. Ultra performance liquid chromatography-mass spectrometry(UPLC-MS) combined with bioinformatics analysis was applied to detect the testicular metabolic profile and screen differential metabolites(DMs). Metabolite set enrichment analysis and pathway enrichment analysis of DMs were performed using MetaboAnalyst, and DMs involved in significantly enriched metabolic pathways were quantitatively analyzed according to different FLC exposure doses. The changes in tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) were detected by double-antibody enzyme-linked immunosorbent assay(ELISA).

Results After 28 days of exposure to 375 mg/(kg·d) FLC, obvious pathological damage was observed in the seminiferous tubules of mouse testes. FLC exposure caused metabolic disturbances in mouse testicular tissue, and the 73 screened DMs were mostly lipids and carboxylic acids, mainly including fatty acids and their complexes, indole carboxylic acids, and steroids. These DMs were mainly enriched in metabolic pathways such as riboflavin metabolism, sphingolipid metabolism, arachidonic acid metabolism, and ketone body metabolism. Quantitative analysis of DMs showed that riboflavin levels were significantly decreased in the 375 mg/(kg·d) FLC-exposed group (P < 0.000 1). The levels of sphingosine, prostaglandins, and 3-hydroxybutyric acid were significantly increased in the 375 mg/(kg·d) FLC-exposed group (P < 0.05). Additionally, the levels of pro-inflammatory factors TNF-α and IL-1β were significantly elevated in the 375 mg/(kg·d) FLC-exposed group (P < 0.01).

Conclusions FLC exposure could cause pathological damage to mouse testes and alter the testicular metabolic profile, mainly affecting lipid metabolism and sex hormone metabolism, which suggested the occurrence of testicular inflammatory responses. This study provided new insights into the mechanism of FLC-induced testicular toxicity.