Abstract
BACKGROUND: Oxidative stress significantly contributes to male infertility. Spirulina contains phycocyanin (PC), a protein with significant biological effects, including strong antioxidant activity. OBJECTIVE: This study investigates the protective effects of Spirulina platensis (Sp) and its active compound, PC, against oxidative damage in sperm and testicular tissue in rats. MATERIALS AND METHODS: This research was an experimental study. 36 male Wistar rats (7-8 wk, 180-220 gr) were randomized into 6 groups (n = 6/each): control, PC (500 mg/kg/day), Sp (300 mg/kg/day), hydrogen peroxide (HP; 0.5%), HP+PC, and HP+Sp. Treatments were given orally for 60 days. Sperm parameters (count, motility, viability) were assessed via Neubauer chamber, motility analysis, and eosin Y staining. Oxidative markers and histopathology were evaluated using colorimetric kits and hematoxylin and eosin staining. DNA fragmentation index (DFI) was measured via acridine orange. RESULTS: HP reduced sperm count (40.2 vs. 55.2 million/mL; p = 0.001), motility (43.4% vs. 87.0%; p = 0.001), and increased DFI (18.5% vs. 4.0%; p = 0.001) versus control. Co-treatment with PC/Sp improved motility (HP-PC: 69.0%, HP-Sp: 61.9%; p = 0.001 vs. HP) and DFI (15.7%; p = 0.001 vs. HP). HP decreased superoxide dismutase and catalase and elevated malondialdehyde (p = 0.001). PC/Sp partially restored superoxide dismutase, reduced malondialdehyde (3.8-3.9 nmol/mL; p = 0.001 vs. HP). PC enhanced total antioxidant capacity (5.6 vs. 3.1 mmol; p = 0.001), while Sp lowered oxidative stress index (0.41 vs. 1.36; p = 0.001) versus HP. CONCLUSION: Sp and PC protect against oxidative sperm and testicular damage by enhancing antioxidant defenses and reducing oxidative stress. PC demonstrated superior effects on sperm quality, DNA integrity, and testicular histology, indicating its therapeutic potential in male infertility.