Titanium nanostructure mitigating doxorubicin-induced testicular toxicity in rats via regulating major autophagy signaling pathways

Doxorubicin (DOX) is a powerful antineoplastic FDA-approved anthracycline-derived antibiotic and is considered as the most suitable intervention for solid tumors and hematological cancers therapy. However, its therapeutic application is highly limited due to acute and chronic renal, hematological and testicular toxicity. Oxidative stress, lipid peroxidation and apoptosis in germ cells as well as low sperm count, motility and disturbing steroidogenesis are the principal machineries of DOX-induced testicular toxicity. Nevertheless, the comprehensive molecular pathways responsible for DOX-induced testicular damage are not yet fully understood. The current study aims to clarify the role of autophagy and apoptotic signaling pathways in testicular toxicity induced by DOX in the rat model. The study also investigates the potential role of both titanium dioxide nanoparticles (TiO₂NP) loaded with DOX and Lactoferrin in combination with DOX in mitigating testicular toxicity induced by DOX the standard antitumor drug. In the present study, male Wister albino rats were intoxicated with a total cumulative dose of DOX (18 mg/kg) via intra-peritoneal injection and served as positive control group. The other two groups administered either TiO₂NP-DOX or lactoferrin-DOX. Furthermore, biochemical and molecular analyses were then performed. DOX intoxication induced testicular toxicity, revealing mineral imbalance as indicated by an increase in both calcium and magnesium concentrations. Administration of either TiO₂NP-DOX or lactoferrin-DOX resulted in a significant modulation of disrupted mineral concentrations, with TiO₂NP-DOX showing superiority in modulating both magnesium and calcium concentrations. Acid Phosphatase level significantly increased upon DOX-induced testicular damage. Molecular analysis of EGFR and K-RAS gene expression showed significant overexpression, while p53 and JAK-2 gene expression was significantly reduced post-DOX intoxication. Protein expression of both AKT and PI3K significantly increased upon DOX administration. Results showed a remarkable modulation of all disrupted gene and protein expressions upon treatment with TiO₂NP-DOX or Lactoferrin-DOX with the superiority of TiO₂NP-DOX in modulating these parameters. In conclusion, TiO₂NP-DOX could be a promising drug delivery system to improve bioavailability and drug release, as well as reducing DOX's adverse effects particularly on testicular function.