Antioxidant supplementation in mammalian ovarian tissue cryopreservation: a scoping review of experimental models,...

Cryopreservation of ovarian tissues represents an important strategy for fertility preservation for patients undergoing gonadotoxic treatments; however, post-thaw tissue viability remains limited. The addition of antioxidants to cryopreservation media has been proposed to mitigate oxidative damage, although published results remain inconsistent across species, cryopreservation protocols, and antioxidant types and doses. This scoping review mapped the available experimental evidence on antioxidant supplementation in cryopreservation media for mammalian ovarian tissue, including human tissue, with emphasis on the compounds evaluated, experimental models, cryopreservation protocols, outcome domains, and reported post-thaw or post-warming responses. A total of 815 records were retrieved, and 27 studies were included, yielding 38 independent experimental conditions. Most studies were conducted in mice (22.2%), cattle (18.5%), sheep (14.8%), and rats (14.8%). Most experimental conditions reported at least one favorable outcome after antioxidant supplementation, although the assessed endpoints, time points, and reporting approaches varied substantially across studies. Melatonin was the most frequently investigated compound and was associated with favorable findings across different species and cryopreservation protocols; limited post-transplantation functional data were additionally reported for glutathione, epigallocatechin gallate (EGCG), and L-proline. Several other antioxidants [glutathione, EGCG, Tanshinone IIA, α-lipoic acid, kisspeptin, vitamins C and E, anethole, robinin, selenium, L-proline, aloe vera, betaine, Trolox (a water-soluble vitamin E analog), α-tocopherol, catalase, Croton argyrophyllus essential oil, and Punica granatum extract] were reported in narrower or more context-dependent experimental settings, suggesting that species, cryopreservation method, antioxidant type, concentration, and assessment conditions may influence the observed responses. Collectively, the mapped evidence indicates a heterogeneous and predominantly preclinical literature in which antioxidant supplementation is often associated with favorable post-cryopreservation findings; however, standardized protocols, harmonized outcome reporting, and long-term functional assessments are needed to clarify the comparative relevance and translational applicability of these approaches.