Curcumin Protects Human Sperm Quality During Cryopreservation

Background: Cryopreservation causes harmful effects on sperm quality due to reactive oxygen species (ROS) overproduction and physical-chemical modifications, resulting in reduced sperm fertility potential. Recently, many studies have shown that adding antioxidants to the cryopreservation medium can markedly reduce these damages. The present study aimed to evaluate the effects of pre-treatment with curcumin at 0, 20, 50, and 100 μM concentrations on frozen-thawed human sperm parameters. Methods: Semen samples from 25 normozoospermic men were collected. Then, each sample was divided into five equal parts: fresh group and frozen-thawed groups, including 0, 20, 50, and 100 μM of curcumin. Pre-cryopreservation and post-thaw sperm motility, morphology, vitality, DNA fragmentation, and ROS levels were investigated. Results: Cryopreservation significantly reduced sperm quality. A known value of 50 μM curcumin significantly improved sperm progressive motility (18.67 ± 1.12 vs. 11.2 ± 1.24, p < 0.01), vitality (35.50 ± 1.63 vs. 21.83 ± 2.64, p < 0.05), and decreased ROS levels (p < 0.05), 50 μM curcumin also efficiently preserved sperm morphology after thawing (13.55 ± 0.33 vs. 6.56 ± 0.16, p < 0.001). Furthermore, the application of 50 μM curcumin resulted in a reduction in DNA fragmentation, though it did not reach statistical significance (p = 0.08). In contrast, 20 μM curcumin only had a significant impact on progressive motility (15.85 ± 0.7 vs. 11.2 ± 1.24, p < 0.05), whereas, in the 100 μM group, there were no significant differences in any of the measured parameters compared with the control group. Conclusion: It seems that curcumin ameliorates cryopreservation-induced injury to sperm.