Selenomethionine antagonizes sodium arsenite-induced reproductive toxicity in zebrafish.

Sodium arsenite (NaAsO₂) contamination in food and water poses a significant threat to human health, with its reproductive toxicity requiring further investigation. Selenium (Se), an essential trace element, has been shown to combat oxidative damage, enhance immunity, and mitigate the toxicity of heavy metals. This study examined the ameliorative effect of organic selenomethionine (Se-Met) against AsIII-induced reproductive toxicity in zebrafish. Zebrafish were exposed to 300 μg/L AsIII and fed a diet supplemented with Se-Met (1 μg/g) either prophylactically or therapeutically. Behavioral analysis revealed that AsIII exposure disrupted courtship behavior and reduced spawning, whereas Se-Met treatment partially restored normal spawning activity. Histological examination showed decreased sperm counts in AsIII-exposed males, which were ameliorated restored by Se-Met. At the molecular level, AsIII exposure down regulated Cyp11a, Cyp17a and Cyp19a1b in gonads, as well as Fshβ and Cyp19a1a in the brain, while Se-Met supplementation partially reversed these effects. In addition, CYP17A1 protein expression in spermatogonia was markedly reduced by AsIII but showed a clear recovery tendency following Se-Met treatment. In conclusion, low-dose Se-Met supplementation partially alleviates AsIII-induced reproductive toxicity in zebrafish, supporting its potential role as a partially ameliorative agent against sodium arsenite exposure.