Synergistic reproductive toxicity of lambda-cyhalothrin and thiamethoxam via oxidative stress and blood-testis barrier dysfunction in rats.

Excessive pesticide use regularly pollutes the environment and endangers both human and animal health. The current study aimed to examine the main mechanism by which the combined action of pyrethroids, such as lambda-cyhalothrin (LC), and neonicotinoids, such as thiamethoxam, induced testicular toxicity and oxidative stress. Four groups of adult male rats were formed: control, Lambda-cyhalothrin (LC; 8 mg/kg B.W.), Thiamethoxam (TMX; 156 mg/kg B.W.), and LC + TMX groups. For 21 days, the rats received their doses orally. Results showed that LC and/or TMX caused significant alterations in body weight, gonadosomatic index, sperm quality, hormones, lipid peroxidation, DNA toxicity, and enzymatic and non-enzymatic antioxidants. Furthermore, testicular tissue showed biochemical, genes expression (steroid-forming acute regulatory protein (StAR), Cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17a), luteinizing hormone receptor (LHR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), scavenger receptor class B type I (SR-B1), 3β-hydroxysteroid dehydrogenase (3β-HSD), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), Claudin-11, Occludin and ZO-1), and ultrastructural abnormalities. In conclusion, rats given both LC plus TMX had strong adverse effects, suggesting oxidative stress and reproductive toxicity.