Novel bisphosphonate derivative partially attenuates iron-associated oxidative stress in doxorubicin-induced testicular injury.

Doxorubicin (DOX), an anthracycline chemotherapeutic agent, induces significant male reproductive toxicity, however, its molecular mechanisms remain incompletely defined. Although oxidative stress is implicated in DOX-induced testicular injury, the roles of iron dysregulation and antioxidant suppression have not been fully characterized in the testis. We investigated time-dependent effects of DOX on testicular morphology, iron homeostasis, and oxidative stress, and evaluated the potential protective effects of (4-(methylthio)phenylthio) methane bisphosphonate (MPMBP), an iron-chelating and antioxidant compound. Male ICR mice received a single intraperitoneal injection of DOX (5 mg/kg). In Experiment 1, testes were collected at 24 h, 48 h, and 1-5 weeks to assess morphological changes, germ cell counts, transcriptional alterations in apoptosis-, antioxidant-, and iron metabolism-related genes, and iron deposition using electron probe microanalysis (EPMA). In Experiment 2, MPMBP (10 mg/kg) was administered either concomitantly with DOX or starting 5 days later, and testicular endpoints were evaluated at 5 weeks. DOX induced progressive testicular atrophy and depletion of early-stage germ cells. Apoptosis-related genes exhibited biphasic upregulation, accompanied by iron accumulation and downregulation of Gpx4 and mitochondrial ferritin (Ftmt). EPMA confirmed iron deposition within seminiferous tubules and interstitial regions. MPMBP co-administration was associated with partial preservation of testicular architecture, reduced iron accumulation, and modest restoration of Gpx4 and Ftmt expression, although these effects were incomplete under the present experimental conditions. These findings associate iron dysregulation and impaired antioxidant defense with DOX-induced testicular injury and support further preclinical investigation of iron-chelating and antioxidant strategies aimed at mitigating chemotherapy-associated reproductive toxicity.