Deciphering the dose-dependent nephrotoxic mechanisms of etoxazole: Insights from redox signaling and Wnt/β-catenin axis

Etoxazole (ETZ) is a selective acaricide that is reported to induce severe organ toxicity including renal impairments. The current research was conducted to evaluate the dose-dependent toxic effects of ETZ on renal tissues. Thirty-six male Sprague Dawley rats were divided into control, ETZ (2.2 mg/kg b.w/day), ETZ (11 mg/kg b.w/day), and ETZ (22 mg/kg b.w/day) treated group. It was found that ETZ intoxication upregulated the mRNA expressions of Wnt family member 1 (Wnt1), Wnt family member 4 (Wnt4), β-catenin, and dickkopf Wnt signaling pathway inhibitor 1 (DKK1) while downregulating the expression of glycogen synthase kinase 3 beta (GSK-3β) in dose-dependent manner. Moreover, ETZ exposure provoked renal oxidative stress via inhibiting the activities of catalase (CAT), glutathione peroxidase (GPx), hemoxygenase-1 (HO-1), glutathione reductase (GSR), glutathione S-transferase (GST), superoxide dismutase (SOD), and contents of glutathione (GSH) while increasing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Similarly, ETZ showed severe alterations in renal function markers as evidenced by increased concentration of Neutrophil gelatinase-associated lipocalin (NGAL), urea, creatinine, cystatin C, osteopontin, Kidney injury molecule 1 (KIM-1), and endothelin-1 while reducing the concentrations of creatinine clearance. Renal tissues showed pro-inflammatory responses at all the tested doses of ETZ as indicated by elevated levels of nuclear factor-kappa B (NF-κB), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) & cyclooxygenase-2 (COX-2). Furthermore, a sharp escalation in the levels of cysteine–aspartic acid protease-3 (Caspase-3), Bcl-2-associated X protein (Bax), and cysteine–aspartic acid protease-9 (Caspase-9) coupled with a significant reduction in the levels of B-cell lymphoma 2 (Bcl-2) was observed following the administration of ETZ. Besides, renal tissues showed high rate of disruption in morphology at all the tested doses of ETZ thereby suggesting its reno-toxic effects. Our computation analysis showed that ETZ strongly bind with key regulatory genes thereby altering their expressions. These findings suggest that ETZ is a potent reno-toxic agent at low, moderate, and high dose administration.