Insights into soy lecithin and egg yolk-based extenders for chilling canine spermatozoa

Abstract

SummaryThe aim of this study was to compare different concentrations of soy lecithin (LEC0.01%, LEC0.05% and LEC0.1%) with egg yolk (Control) in cooling extenders during the storage of semen at 5ºC for 5 days. Twelve dogs (n = 12) were selected, and semen was cooled and assessed after 2, 24, 48, 72, 96 or 120 h. At each time point, sperm were analyzed for kinetic patterns (using computer-assisted sperm analysis), mitochondrial activity (3′3- diaminobenzidine assay), lipid peroxidation (TBARS assay), DNA fragmentation (SCSA®) and plasma and acrosome membrane integrity (eosin/nigrosin and fast green/rose Bengal stains, respectively). The Control group (1814.4 ± 197.2) presented the highest rates of lipid peroxidation at 120 h. Conversely, progressive motility (42.8 ± 4%), linearity (45.4 ± 1%), and VAP (88 ± 3%) were higher in the Control group. In addition, there was lower mitochondrial activity in the Control group at 72 h. Therefore, our data show that lecithin used at these concentrations was not able to maintain sperm viability at as high qualities as would egg yolk. Moreover, the decrease in high mitochondrial activity and the persistence of sperm motility may indicate a compensatory mechanism in canine spermatozoa (i.e., glycolytic pathway). Furthermore, these higher lipid peroxidation indexes could indicate the necessity for future therapy using extenders and antioxidants over a long cooling time for dog sperm.

Vitrification Using Soy Lecithin and Sucrose: A New Way to Store the Sperm for the Preservation of Canine Reproductive Function

“…However, increasing the concentration of soy lecithin to 1% led to promising results on post-thaw semen viability and acrosome integrity in the current study, which is in agreement with previous studies [16,29,30]. This finding supports previous suggestions that high concentrations of soy lecithin are necessary to maintain canine sperm characteristics (i.e., motility kinetics) during storage [28]. Besides that, the type of soy lecithin used as a base in the extender seems to be very important, since different lecithin products contain different concentrations of phosphatidylcholine [16], which has an important role in incorporating choline in the polar region of spermatozoa plasma membrane and plays an active role in sperm capacitation and acrosome reaction.…”

“…Soy lecithin can also serve as an antioxidant and can protect semen from oxidative stress resulting in higher viability and motility after cryopreservation [16]. A recent study in dogs showed that soy lecithin at low concentrations (0.01%, 0.05%, and 0.1%) was not able to maintain sperm characteristics when compared to egg-yolk-based extenders [28]. However, increasing the concentration of soy lecithin to 1% led to promising results on post-thaw semen viability and acrosome integrity in the current study, which is in agreement with previous studies [16,29,30].…”

Beneficial Influence of Soybean Lecithin Nanoparticles on Rooster Frozen–Thawed Semen Quality and Fertility

“…Our findings revealed that among the test concentration range of SL (0.5-2%), the best concentration of SL for cryopreservation of rooster semen was 1.0%. However, previous sperm studies for semen cryopreservation in other species demonstrated that the optimal SL concentration ranged from 0.8 % in canines [9], 1.5% in bulls [8], 2% in rams [7], and 6% in boars [28]. This inconsistency may be related to species-specific differences.…”

“…It also acts as an antioxidant against free radical damage, resulting in improved viability and motility after cryopreservation. Many studies confirm the beneficial impact of SL for semen cryopreservation in bulls [8], rams [7], canines [9], bears [10], and so on. A previous study from our laboratory demonstrated that 20% egg yolk and 2.0% SL added to the extenders produced similar protective effects on goat semen cryopreservation [11].…”

Wedelolactone-Loaded Micelles Ameliorate Doxorubicin-Induced Oxidative Injury in Podocytes by Improving Permeability and Bioavailability

“…The delivery system of micelles is composed of a mixture of surfactants, lecithin, and natural antioxidants (Li et al, 2017). Increasing evidence shows that the extraction of lecithin from egg yolk has potential health-enhancing antioxidant properties involving superoxide anion and hydroxyl radical scavenging and ferrous chelation (Dalmazzo et al, 2019). Another study demonstrated that the antioxidant activity of lecithin emulsifier significantly influenced the permeation of free radicals across the emulsion interface (Chung et al, 2019).…”