Effects of different concentrations of zinc oxide nanoparticles on the quality of ram cauda epididymal spermatozoa during storage at 4°C.

Zinc oxide nanoparticles (ZnO-NPs) are known for their antioxidant effects. In this study, ZnO-NPs were synthesized using aqueous extract of Maclura pomifera fruit; then, their effects on the quality of ram cauda epididymal spermatozoa were evaluated during storage at 4°C. ZnO-NPs formation was characterized by ultraviolet-visible spectroscopy (UV-vis), energy dispersive spectroscopy (EDX), field emission scanning electron microscopes (FE-SEM) and Fourier transform infrared (FTIR) spectroscopy. Cytotoxicity responses were investigated by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT). Cauda epididymal spermatozoa were obtained from testicles collected from abattoir(s). The sperm samples were pooled. The samples were diluted by extender and supplemented with different concentrations of ZnO-NPs (0, 1, 5 and 25 µg/ml) and cooled to 4°C for 72 hr. Total motility, viability, DNA and membrane integrity, morphological abnormality, malondialdehyde (MDA) and antioxidant activities: superoxide dismutase (SOD) and total antioxidant capacity (TAC) of cooled diluted samples were evaluated. Addition of 1 µg/ml of ZnO-NPs increased sperm viability under normal conditions (p < .05). Extender supplementation with 1 µg/ml of ZnO-NPs improved sperm total motility, viability, DNA and membrane integrity during storage periods (p < .05). Moreover, using 1 µg/ml of ZnO-NPs improved (p < .05) MDA, TAC and SOD activities after 72 hr compared to other treatments. In conclusion, there were some beneficial effects of ZnO-NPs supplementation in ram epididymal sperm extender during oxidative stress conditions and cooled storage.

Effects of different concentrations of Chir98014 as an activator of Wnt/beta-catenin signaling pathway on oocyte in-vitro maturation and subsequent embryonic development in Sanjabi ewes.

The present study was conducted to investigate the effects of the activator factor of the WNT pathway, chir98014, leading to the in vitro sheep oocyte maturation medium, on the cumulus cell development, different nuclear maturation stages and the following process of embryonic development. Experiments included (a) addition of different concentrations (0, 0.1, 0.5, 1 µm) of chir98014 to the maturation medium and evaluation of the cumulus cell expansion, (b) addition of different concentrations of chir98014 to the maturation medium and investigation of different nuclear maturation stages, (c) addition of different concentrations of chir98014 to the maturation medium and examination of the subsequent embryonic maturation process and (d) addition of different concentrations of chir98014 to the embryonic development culture medium (the first 48 hr) and investigation of the subsequent embryonic development process. The extracted data were analysed using the SPSS software, considering the significance level of p < .05 and making the mean comparisons. The results showed that the addition of the 0.1 µM concentration of chir98014 to the maturation medium had no significant effects on the oocyte maturation and embryo development post-fertilization but it enhanced the Cumulus-oocyte complexes (COCs) expansion. In the fourth experiment, the low concentration of chir98014 in the embryo culture media improved the embryo development process, whereas the high one had a detrimental effect on it, as compared to the control group. Thus, the presence of the lower concentrations of this compound in the embryonic culture medium had favourable effects on the development of embryos.