The addition of docosahexaenoic acid (DHA) and antioxidants (glutathione peroxidase and superoxide dismutase) in extenders to epididymal sperm cryopreservation in bulls

Abstract

SummaryThe cryopreservation of epididymal sperm is an important technique that allows genetic material to be preserved, even post mortem. However, cryopreservation leads to increased oxidative stress and impaired sperm viability. Polyunsaturated fatty acid (PUFA) supplementation may improve certain sperm characteristics, but it also makes sperm more susceptible to oxidative stress, therefore adding antioxidants that counteract oxidative stress has become an option. In this context, this study aimed to evaluate the effect of the interaction between docosahexaenoic acid (DHA) and antioxidants on the quality after the cryopreservation of epididymal bull sperm. Twenty epididymides were collected after slaughter, and epididymal sperm was cryopreserved with bovine extender supplemented with docosahexaenoic acid (DHA), glutathione peroxidase (GPx) and superoxide dismutase (SOD). We verified an improvement in motility in the group that was treated only with DHA 5 µM and a concentration-dependent effect on susceptibility to lipid peroxidation that was associated with DHA concentration (1 µM, 5 µM or 10 µM). Moreover, treatment with DHA (5 µM) and SOD (20 IU/ml) resulted in higher sperm motility. Thus, the association between DHA (5 µM) and SOD (20 IU/ml) appears to be an option for increased epididymal sperm features in bulls.

Effects of the addition of docosahexaenoic acid and ?-tocopherol on quality of equine spermatozoa stored at 5°C

“…Differently of other findings (Kaka et al, 2015;Silva et al, 2017;Losano et al, 2018) the addition of DHA to the semen caused an unexpected effect on the lipid peroxidation in this experiment. The fact that this fatty acid has six double bonds makes it more susceptible to attack by ROS.…”

“…This test has not detected any significant difference between treatments, but it has exhibited reduced DAB I class during the storage period, reflecting the energy expenditure. These findings are in agreement with other studies where, in stallions and bulls frozen semen, the addition of α-Toh and DHA, respectively, has not affected mitochondrial activity (Baumber, Ball, & Linfar, 2005;Franco, Chaveiro, Góis, & Silva, 2013;Losano et al, 2018).…”

“…DHA addition to frozen boar semen increased PMI preservation (Kaeoket et al, 2010). In bull frozen-tawed semen, 10 ng mL -1 or 10 μM of DHA had no effect on PMI (Nasiri et al, 2012;Towhidi & Parks, 2012;Losano et al, 2018), but 3 ng mL -1 protected PM from injuries due this process (Kaka et al, 2015). Our results were different from those presented by Silva et al (2017), who found a protective effect on the plasma membrane when adding the combination of DHA and α-Toh.…”

“…Such incorporation increases the fluidity of PM and can contribute to sperm motility (Connor et al, 1998), since the level of DHA in PM is positively correlated with this seminal parameter (Zerbinati et al, 2016). In frozen boar semen (Kaeoket, Sang-Urai, Thamniyom, Chanapiwat, & Techakumphu, 2010) and bull epididymal cryopreserved sperm (Losano et al, 2018), the addition of DHA resulted in increased motility and it was attributed to the incorporation of this PUFA to the PM, helping with the membrane phase transition from liquid crystal to gel state. In horses, the use of nutraceutical rich in DHA modified the sperm PM composition, which resulted in a lower decline of motility in cooled semen for 48 hours.…”

Effect of sheep diets with macadamia by-product and protected fat on the quality of fresh and frozen semen

“…The ovine spermatozoon has a higher ratio of polyunsaturated and saturated fatty acids and a lower ratio of cholesterol and molar phospholipid compared to that of other species, making the cell considerably more vulnerable to oxidative damage caused by ROS (MOTLAGH et al, 2014). There is a greater predisposition of polyunsaturated fatty acids to undergo lipo peroxidation (LOSANO et al, 2018). According to Moraes et al (2010), animals on diets supplemented with salmon oil showed a decrease in the total antioxidants in the semen, since this food is rich in PUFAs, resulting in a greater predisposition to lipid peroxidation.…”