No abstract

This study aimed to investigate the effects of different concentrations of N-acetylcysteine (NAC) on the growth, antrum formation, viability, and ultrastructure of bovine secondary follicles cultured in vitro for 18 days. To this end, the follicles were cultured in TCM-199+ medium alone or supplemented with 1.0, 5.0, or 25.0 mM NAC. Follicular growth, antrum formation, viability (calcein-AM and ethidium homodimer-1) and ultrastructure were evaluated at the end of culture period. The results showed that 1.0 mM NAC increased the percentage of growing follicles and the fluorescence intensity for calcein-AM when compared to other treatments (p < 0.05). On the other hand, follicles cultured with 25.0 mM NAC had higher fluorescence intensity for ethidium homodimer-1, which is a sign of degeneration. Ultrastructural analysis showed that oocytes from follicles cultured in control medium alone or with 1 mM NAC had intact zonae pellucidae in close association with oolemmae, but the ooplasm showed mitochondria with a reduced number of cristae. On the other hand, oocytes from follicles cultured with 5 or 25 mM NAC had extremely vacuolated cytoplasm and no recognizable organelles. In conclusion, 1 mM NAC increases cytoplasmic calcein staining and the growth rate in bovine secondary follicles cultured in vitro, but the presence of 5 or 25 mM NAC causes damage in cellular membranes and organelles, as well as reducing the percentages of growing follicles.

No abstract

Assisted reproductive technology (ART) have contributed to preserve fertility in humans and to increase multiplication of genetically superior animals. Despite being highly practiced worldwide, ART presents some challenges, especially because gametes and embryos are kept in vitro for a variable period of time, and the oxidative stress in vitro can have negative impact on oocyte competence and embryo development. Nanotechnology needs to be considered to help overcome some of those impairments, since it can provide strategies to deliver antioxidants and hormones to gametes and embryos in vitro. The application of nanotechnology to ART can allow the development of new protocols using nanomaterials to improve in vitro oocyte competence and embryo production. This review discusses the applicability of nanomaterials to improve sperm selection, to deliver antioxidants and hormones to preantral follicles, oocytes, and embryos in vitro, as well as the concerns about using nanotechnology in ART.

This study evaluated the potential of Cimicifuga racemosa (L.) Nutt extract (CIMI) to reduce the deleterious effects of doxorubicin (DOXO) in oocytes, follicles and stromal cells in mice ovaries cultured in vitro. In experiment 1, mice ovaries were cultured in DMEM+ alone or supplemented with 5, 50 or 500 ng/mL CIMI, while in experiment 2, mice ovaries were cultured in DMEM+ alone or supplemented with 5 ng/mL CIMI (better concentration), 0.3 μg/mL DOXO or both. Thereafter, the ovaries were processed for histological (morphology, growth, activation, extracellular matrix configuration and stromal cell density), immunohistochemical (caspase-3) analyses. Follicle viability was evaluated by fluorescence microscopy (ethidium homodimer-1 and calcein) while real-time PCR was performed to analyses the levels of (mRNA for SOD, CAT and nuclear factor erythroid 2–related factor 2 (NRF2) analyses. The results showed that DOXO reduces the percentage of normal follicles and the density of stromal cells in cultured ovaries, but these harmful effects were blocked by CIMI. The DOXO reduced the percentage of primordial follicles, while the presence of CIMI alone did not influence percentage of primordial follicles. A higher staining for caspase-3 was seen in ovaries cultured in control medium alone or with DOXO when compared with those cultured with CIMI alone or both CIMI and DOXO. In addition, follicles from ovaries cultured with both CIMI and DOXO were stained by calcein, while those follicles cultured with only DOXO were stained with ethidium homodimer-1. Furthermore, ovaries cultured with CIMI or both CIMI and DOXO had higher levels of mRNA for SOD and CAT, respectively, than those cultured with only DOXO. In conclusion, the extract of CIMI protects the ovaries against deleterious effects of DOXO on follicular survival and ovarian stromal cells.