Curcumin as a protective agent for goat sperm viability and DNA integrity against bisphenol A toxicity and cryopreservation stress.

Oxidative stress induced by environmental toxicants such as Bisphenol A (BPA) and cryopreservation significantly impairs sperm quality in goats, leading to reduced viability, motility, membrane integrity, and increased DNA fragmentation. This study aimed to evaluate the protective effects of curcumin, a natural polyphenolic antioxidant on goat sperm exposed to BPA and cryopreservation stress in vitro. Three experiments were conducted using semen collected from healthy adult goats. In Experiment 1, sperm samples were treated with 30 µM BPA to induce oxidative damage, followed by curcumin supplementation at 0, 5, 10, and 20 µM. In Experiment 2, freshly collected semen was cryopreserved in liquid nitrogen (- 196 °C) with the same curcumin concentrations added to the freezing extender. In Experiment 3, commercial frozen goat semen straws were thawed in media supplemented with curcumin at identical concentrations. Each treatment was replicated 12 times. BPA exposure significantly decreased overall motility and progressive motility compared to control. Treatment with 10 µM curcumin effectively restored sperm quality. In cryopreserved samples, 5 µM curcumin provided optimal protection. Similarly, in thawed commercial semen, 5 µM curcumin significantly improved sperm performance. These results demonstrate that curcumin at optimal concentrations effectively mitigates oxidative stress-induced damage to goat sperm, whether from BPA toxicity or cryopreservation. The dual role of curcumin during both freezing and thawing underscores its practical value as an antioxidant additive in semen preservation protocols. Its inclusion could enhance sperm quality, promote fertility outcomes, and support reproductive biotechnology applications in animal breeding programs.