The interference of ozone gas in kinects and mitochondrial potential of equine sperm submitted on cryopreservation

Impact of low-dose ozone supplementation on motility parameters and bacterial growth in horse cryopreserved semen

Two studies were conducted to evaluate the use of medical ozone (O3) in commercial extenders for equine semen cryopreservation. In the first study (Study 1), 0, 5, and 15 µg/mL of O3 were added to diluents of refrigerated or frozen semen. Samples were evaluated for sperm kinematics at different time points for the chilled samples and after a thermoresistence test for the frozen/thawed samples. In the second study (Study 2), 0, 5, and 10 µg/mL of O3 were added to an antibiotic-free diluent for refrigerated semen for comparison with the control group in which semen was diluted in the same diluent enriched with antibiotics. Semen sample kinematics were analyzed and an aliquot was collected after ozonification for bacteriological analyses. For Study 1 no difference was found comparing all the kinematic parameters analyzed over time, in the various treatments (P > 0.05). In Study 2 the absence of antibiotics did not affect the kinematic parameters compared to the control (P > 0.05). However when antibiotics were added, a smaller number of bacterial colony-forming units were detected compared to samples without antibiotics and without or with different O3 supplementations. In conclusion, O3 treatment at low dosages did not affect the semen kinematics, although it was ineffective in preventing bacterial overgrowth. Higher O3 concentrations should be evaluated to explore the possibility of reducing the use of antibiotics in equine sperm conservation.

Evaluation of Cryopreserved Ram Sperm with Nano-Ozone Solution and Post-Thaw Life Span by Flow Cytometric Analysis

Ozone has been used as a therapy tool in medical science for conditions such as ulcers, peritonitis, wounds, and mostly joint problems. Ozone therapy strengthens the resistance to infections by kick-starting antioxidant, anti-inflammatory, and immune modulation systems. Ozone creates a defensive response against oxidative stress in membranes and protects metabolism against reactive oxygen species (ROS). Sperm membranes are one of ROS's main targets; therefore, the cells' cryopreservation process requires more defensive elements for better results. This study aimed to investigate the protective effect of nano-ozone solution (NOS) on ram sperm cryopreservation and the influence of the process on various sperm parameters for post-thaw (0 hour) and postincubation (6 hours) time points. Samples were collected from six Merino rams in the breeding season by electroejaculation five times at 3-day intervals. The study was conducted by cryopreservation of the samples using a tris citric acid-egg yolk-based extender. The samples were subjected to freezing in control and NOS (0.5, 1, and 2 μg/mL nano-ozone supplemented). Post-thaw motility, hypo-osmotic swelling test, acrosome (fluorescein isothiocyanate-conjugated Pisum sativum agglutinin [PSA-FITC]), and DNA integrities (terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL]) were evaluated with a phase-contrast microscope. Mitochondrial membrane potential (MMP) assessments were conducted by JC1-PI dual staining with a flow cytometer. Malondialdehyde and glutathione (GSH) levels were measured by a spectrophotometer. Sperm kinematics were investigated by a computer-assisted sperm analyzer (CASA) at the post-thaw time point. Compared with the control, relatively low doses of NOS (0.5 and 1 μg/mL) yielded better results in many parameters (motility, membrane and acrosomal integrities, MMP, various sperm kinematics, and GSH levels) (p < 0.05). The addition of low ozone doses to cryopreservation extenders improved the results compared with the control group at post-thaw and postincubation time points. Despite the valuable potential of nano-ozone supplementation in ram sperm cryopreservation, this subject requires further investigations with fertility trials soon.