Melatonin Regulates Clusterin to Reconstruct the Blood–Testis Barrier Disrupted by Atrazine

Atrazine (ATZ), a commonly used triazine herbicide, is known to impair male reproductive function. Melatonin (MLT) is an endogenous hormone synthesized by the pineal gland. Its lipophilic nature enables it to freely penetrate the blood-testis barrier (BTB) and exert direct effects. However, it remains unclear whether MLT can prevent ATZ-induced impairment of BTB function. Pubertal male mice were randomly assigned to four groups and treated via gavage for 21 days: control group (Con), 5 mg/kg melatonin group (MLT), 170 mg/kg atrazine group (ATZ), and cotreatment group (ATZ+MLT). Furthermore, BTB-associated proteins, transepithelial electrical resistance, and cell adhesion assays were performed in TM4 cells treated with siClusterin, pcDNA3.1-Clusterin, and AKT inhibitor VIII to evaluate BTB function in vitro. Our findings demonstrate that MLT effectively restores ATZ-induced reductions in BTB protein levels and function in both in vivo and in vitro models. Moreover, MLT mitigated ATZ-induced BTB damage by reactivating the Clusterin/AKT signaling pathway.