Lycopene as a protective antioxidant in sperm preservation

Sperm preservation is a pivotal technique in reproductive science, facilitating the long-term preservation and utilization of valuable genetic material, particularly in animal breeding programs and assisted reproductive technologies (ART). However, the freezing-thawing process imposes significant physiological stress on sperm cells, primarily due to oxidative damage. This oxidative stress disrupts critical cellular functions, leading to reduced sperm motility, viability, DNA integrity, and membrane stability, thereby compromising overall reproductive potential. Among various antioxidant strategies, lycopene, a potent carotenoid, has emerged as a promising candidate for mitigating cryoinjury. This review provides a comprehensive overview of lycopene's role in sperm cryopreservation and cold storage, emphasizing its effect on post-thaw sperm quality. Experimental evidence from animal studies indicates that lycopene supplementation effectively neutralizes reactive oxygen species, reduces lipid peroxidation, and preserves structural integrity by integrating into cell membranes. These protective effects contribute to enhancing sperm functionality post-thaw, potentially improving fertilization outcomes. Yet, this review critically highlights that the efficacy of lycopene is a double-edged sword: its effects are highly dose- and species-dependent, with excessive concentrations paradoxically impairing sperm performance. We conclude that a 'one-size-fits-all' approach is ineffective, and future investigations must move beyond simple supplementation to focus on optimizing species-specific formulations and validating in vitro benefits with in vivo fertility trials to fully harness lycopene's potential in reproductive applications.