Hesperetin-Loaded PLGA Nanoparticles Ameliorate Cisplatin-Induced Oxidative Stress and Testicular Dysfunction in Rats: Association with NRF2/HO-1, NF-κB, and ACSL4/GPX4/SLC7A11 Signaling Modulation
Background: Cisplatin is a widely used chemotherapeutic agent whose gonadotoxic effects, largely driven by oxidative stress and inflammation, pose a major threat to male reproductive health. This study evaluated whether hesperetin (HES) and hesperetin-loaded poly (lactic-co-glycolic acid) nanoparticles (HES-PLGA-NPs) can protect against cisplatin-induced testicular dysfunction in adult male Sprague Dawley rats. Methods: Sixty rats were randomly assigned to six groups: control, HES, HES-PLGA-NPs, cisplatin (CIS), CIS + HES, and CIS + HES-PLGA-NPs. CIS (7.5 mg/kg/week, i.p.) was given intraperitoneally for four weeks, while HES and nano-HES (50 mg/kg/day, p.o.) were orally administered concurrently. Reproductive hormones, testicular weight, sperm parameters, oxidative stress and antioxidant markers, NRF2/HO-1 and NF-κB signaling, apoptotic indices, ferroptosis-related markers, histopathology, and GPX4/ACSL4 immunoexpression were assessed. Results: CIS caused marked reproductive dysfunction, including reduced testosterone, FSH, and LH, decreased testicular weight, and impaired sperm quality. These changes were associated with severe oxidative and nitrosative stress (↑ MDA, NO, 8-OHdG), depletion of antioxidant defenses (↓ SOD, CAT, GSH), reduced NRF2/HO-1, elevated NF-κB activity and pro-inflammatory cytokines, apoptosis-related changes (↑ Bax, caspase-3; ↓ Bcl-2), and ferroptosis-associated alterations (↑ Fe2+, TFR1, lipid ROS, ACSL4, 4-HNE; ↓ GPX4, SLC7A11). Both HES and HES-PLGA-NPs were associated with significant amelioration of these alterations, but the nanoformulation showed more pronounced protection, normalizing several oxidative and ferroptosis-associated markers toward control levels and more effectively preserving seminiferous tubule architecture and spermatogenesis. Conclusions: HES-PLGA-NPs were associated with multi-mechanistic protection against cisplatin-induced oxidative, inflammatory, apoptotic, and ferroptosis-associated damage in the testes, and may represent a promising nanoantioxidant candidate warranting further investigation for preserving male reproductive function during chemotherapy.