Effect of sulforaphane on apoptosis, reactive oxygen species and lipids peroxidation of human sperm during cryopreservation.

Sperm cryopreservation is a common procedure to preserve viable sperm for an indefinite period. This procedure has numerous detrimental effects on sperm function due to increased generation of reactive oxygen species (ROS). During cryopreservation, while ROS increases, antioxidant enzymes level decreases. It has been shown that a relationship exist between lower antioxidant levels and infertility. l-Sulforaphane (SFN) is an isothiocyanate in cruciferous vegetables of the brassica class that has potent protective effects against oxidative stress. The purpose of the present study was to evaluate the effects of SFN supplementation during the freeze-thaw process on different parameters of human spermatozoa which can influence sperm fertilizing ability. Samples were collected from 25 healthy men and each sample was divided into three groups: fresh, control (untreated frozen/thawed samples) and treatment (treated frozen/thawed with SFN) groups. Sperm parameters, ROS production (using flow cytometry), plasma membrane integrity (using flow cytometry), Lipid peroxidation (using ELISA) were evaluated. Our results demonstrated that 5 μM SFN improved all parameters of sperm including viability (P < 0.001), motility, and morphology (P < 0.05) after the freeze-thaw process. Furthermore, SFN reduced the levels of intracellular hydrogen peroxide (P < 0.01) and superoxide anion (P < 0.05). Also, SFN significantly increased the percentage of viable sperm cells with the intact plasma membrane (P < 0.001) and decreased the level of lipid peroxidation after the freeze-thaw process (P < 0.01).Our findings showed that spermatozoa treatment with 5 μM SFN before the freeze-thaw process has protective effects against oxidative stress and could decrease the detrimental effects of this process on sperm quality.