Centre of Experimental Medicine of the Slovak Academy of Sciences, Bratislava, Slovakia
ABSTRACT. Epoxiconazole is a triazole that serves as a broad-spectrum fungicide, renowned for its enduring efficacy against cereal leaf spots, rust fungi, etc. There is increasing evidence from animal studies that exposure to epoxiconazole may affect reproductive function. Additionally, several studies in rats have confirmed the endocrine-disrupting properties of epoxiconazole. However, there are few studies examining its adverse effects on spermatogenesis.
Aim. This study aimed to assess sperm quality following exposure to two generic pesticides, epoxiconazole (Epox). The test substances epoxiconazole technical were sourced from different manufacturers, and the purity of the active ingredient was at 98. % (Epox-1) and 97.3 % (Epox-2).
Material and Methods. The test substances were administered intragastrically as an aqueous emulsion daily for 10 weeks to two groups of 10 male animals each. The doses administered were 0.5 and 2.0 mg/kg body weight. Control animals, comprising 10 males, were administered an equivalent amount of vehicle, consisting of distilled water with an emulsifier. Upon completion of the exposure period, an assessment of functional indicators of gonadal status was conducted. Specifically, the evaluation included counting motile sperm, total sperm concentration, and quantifying pathological forms of germ cells. Also, the absolute and relative weight of the testes and epididymis were evaluated. The sperm quality of males following exposure to Epox-2 was assessed using a computerised sperm analyser, specifically the CASA (Computer-aided Semen Analysis) SCA® Pack TOX Edition. In the case of Epox-1, the analysis of male sperm was conducted manually, utilising light microscopy.
Results. The findings indicated that exposure to Epox-1 at 2 mg/kg in males resulted in a significant reduction in the number of motile sperm and a decrease in the absolute and relative testicular weights. More severe outcomes were noted following exposure to the test substance Epox-2 at the identical dose of 2 mg/kg body weight. The observations included an elevated proportion of pathological sperm forms and immotile sperm, a decreased percentage of motile sperm, and a reduction in the absolute and relative testicular weights. At a dose of 0.5 mg/kg, neither test substance, Epox-1 nor Epox-2, exhibited a general toxic effect and did not adversely affect gonad function when exposed to male rats.
Conclusions. According to the results, the two test substances, Epox-1 and Epox-2, exhibit notable antiandrogenic activity when administered to male rats at 2 mg/kg body weight. This is evidenced by a deterioration in male sperm quality and a reduction in the weight of their gonads. Furthermore, the observed variation in toxicity following exposure to Epox-2 may be attributable to the lower purity of the test substance relative to Epox-1 in this instance. This underscores the significance of assessing generic pesticides with varying percentages of impurities.
Keywords: epoxiconazole, toxicity, gonads, sperm quality, spermatogenesis, male rat.
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Received February, 3, 2026
Review dates February, 23, 2026; February, 25, 2026
Publication date June, 12, 2026
