Effect of exposure to CeO2 nanoparticles on ram spermatozoa during storage at 4 °C for 96 hours

Abstract

BackgroundCerium oxide nanoparticles (CeO2 NPs) are able to store and release oxygen, conferring them scavenger activity against oxidative stress. However, their effects in reproductive systems are not yet well understood. The aim of the study was to investigate the effects of exposure of refrigerated ram semen to CeO2 NPs for 96 h on the main structural and kinematic parameters of spermatozoa.MethodsThe ejaculates of 5 Sarda rams were collected, pooled and diluted in a soybean lecithin extender. Samples were exposed to increasing doses of CeO2 NPs (0, 44 and 220 μg/mL) and stored at 4 °C for 96 h. Analyses of kinematic parameters (computer assisted sperm analysis, CASA), integrity of membranes (PI/PSA staining), ROS production (H2DCFDA staining) and DNA damage (sperm chromatin structure assay with acridine orange, SCSA) were performed every 24 h (0, 24, 48, 72 and 96 h of incubation). The experiment was carried out in 6 replicates. Data were analysed by repeated measures ANOVA with Bonferroni’s as post hoc test. When the assumption of normality was not met (ROS), non-parametric Kruskal-Wallis rank test was carried out.ResultsExposure of ram spermatozoa to increasing doses of CeO2 NPs had a beneficial effect on the main motility parameters from 48 h of incubation onward. Velocity of sperm cells was enhanced in the groups exposed to CeO2 NPs compared to the control. Incubation with NPs had beneficial effects on the integrity of plasma membranes of spermatozoa, with higher percentage of damaged cells in the control group compared to the exposed ones. Production of ROS was not affected by exposure to NPs and its levels rose at 96 h of incubation. The integrity of DNA remained stable throughout the 96 h of storage regardless of co-incubation with NPs.ConclusionsWe reported beneficial effects of CeO2 NPs on kinematic and morphologic parameters of ram semen, such as motility and membrane integrity following 96 h of exposure. Furthermore, we also proved no genotoxic effects of CeO2 NPs. These effects could not be related to an antioxidant activity of CeO2 NPs, since ROS levels in exposed cells were similar to those of unexposed ones.

The Effect of Adding Different Levels of Curcumin and Its Nanoparticles to Extender on Post-Thaw Quality of Cryopreserved Rabbit Sperm

“…Consequently, the CUNPs can mitigate OS injury through down-regulation of the H2O2 level and protect the spermatozoa from being injured by inflammatory factors, to achieve the purpose of protecting the sperm quality [ 36 ]. Furthermore, Falchi et al [ 37 ] have revealed the antioxidant capability of cerium oxide (CeO2) nanoparticles on ram spermatozoa during storage at 4 °C. This might be related to the amounts of ROS were reduced within the semen extender through storage, which explained into better motion features and sperm viability.…”

Effect of addition of melatonin on liquid storage of ram semen at 4°C

“…The supplementation of semen extenders with antioxidant substances could reduce the deleterious effects of the higher production of ROS and oxidative stress on sperm cells (Falchi, Galleri, Dore et al, ). Melatonin and its metabolites are known as antioxidants and potent free radical scavengers (Harderland et al, ).…”

Perspectives of nanotechnology in male fertility and sperm function

“…Supplementation of CeO 2 in semen extender improved motility parameters after 48 h and up to 96 h of incubation and increased sperm velocity of sperm cells. This was associated with protecting the integrity of plasma membranes and DNA of spermatozoa [12]. These effects could not be linked with any reduction in intracellular ROS as detected by H2DCFDA staining [12], however, the sensitivity of this cytoplasmic stain may not be sufficient to detect minor differences in sperm cells due to the cellular structure of the sperm head which is mostly occupied by a nucleus.…”

“…Semen cooling and cryopreservation are known to increase oxidative stress in spermatozoa leading to a significant reduction in their fertilization capacity [11]. We have recently tested the efficiency of cerium oxide (CeO 2 ) NPs, which are able to store oxygen and act as ROS (reactive oxygen species) scavengers, to protect ram sperm cell viability during cooling [12]. Supplementation of CeO 2 in semen extender improved motility parameters after 48 h and up to 96 h of incubation and increased sperm velocity of sperm cells.…”