RESUMO
Oxidative stress during in vitro of ovarian tissues has adverse effects on follicle survival. α-pinene is a monoterpenoid molecule with antioxidant activity that has great potential to maintain cell survival in vitro. This study investigated the effect of α-pinene (1.25, 2.5, 5.0, 10.0, or 20.0 µg/mL) on primordial follicle growth and morphology, as well as on stromal cells and collagen fibers in bovine ovarian slices cultured for six days. The effect of α-pinene on transcripts of catalase (CAT), superoxide dismutase (SOD), peroxiredoxin 6 (PRDX6), glutathione peroxidase (GPX1), and nuclear factor erythroid 2-related factor 2 (NRF2) was investigated by real-time PCR. The tissues were processed for histological analysis to evaluate follicular growth, morphology, stromal cell density, and collagen fibers. The results showed that 2.5, 5.0, or 10.0 µg/mL α-pinene increased the percentages of normal follicles but did not influence follicular growth. The α-pinene (10.0 µg/mL) kept the stromal cell density and collagen levels in cultured bovine ovarian tissue like uncultured tissues. Ovarian tissues cultured in control medium had reduced expression of mRNA for NRF2, SOD, CAT, GPX1, and PRDX6, but α-pinene (10.0 µg/mL) increased mRNA levels for NRF2 and PRDX6. In conclusion, 10.0 µg/mL α-pinene improves the follicular survival, preserves stromal cell density and collagen levels, and increases transcripts of NRF2 and PRDX6 after in vitro culture of bovine ovarian tissue.
RESUMO
In vitro culture of ovarian tissue containing primordial follicles is an important tool to study the initiation of follicular populations and to develop efficient culture systems to support in vitro follicle growth. Considering that in vitro culture favours oxidative stress, it is very important to supplement culture medium with antioxidant substances such as Aloe vera extract. This study aims to evaluate the effects of different concentrations of Aloe vera on the distribution of collagen fibres in the extracellular matrix, follicular activation, development and survival in bovine ovarian cortical tissues cultured in vitro, as well as on expression of mRNAs for antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxiredoxin 6 (PRDX6) and glutathione peroxidase 1 (GPX1)]. To this end, ovarian cortical tissues were cultured for 6 days in α-MEM alone or supplemented with different concentrations of Aloe vera extract (1.0, 5.0, 10.0 or 50.0%). After culture, fragments were fixed and processed histologically to evaluate follicular morphology and activation, as well as the extracellular matrix by staining with picrosirius red. The levels of mRNA for SOD, CAT, PRDX6 and GPX1 in cultured ovarian tissues were evaluated by real-time polymerase chain reaction (PCR). Ovarian tissues cultured with 10.0 or 50.0% Aloe vera had higher percentages of collagen fibres than tissues cultured in control medium. A significant increase in developing follicles was observed in ovarian tissues cultured in α-MEM alone or supplemented with 10% Aloe vera when compared with fresh control or tissues cultured with 1.0% Aloe vera. Presence of Aloe vera did not influence the percentage of morphologically normal follicles when compared with control medium. Ovarian tissues cultured with 50.0% Aloe vera had higher percentages of morphologically normal follicles than those cultured with 10.0% Aloe vera. Furthermore, 10% Aloe vera significantly increased mRNA levels for PRDX6. In conclusion, 10.0% Aloe vera improves extracellular matrix distribution in cultured tissues and increases the expression of mRNA for PRDX6 after 6 days in vitro.
Assuntos
Aloe , Aloe/genética , Animais , Antioxidantes , Bovinos , Colágeno/genética , Matriz Extracelular , Peroxirredoxina VI , Extratos Vegetais , RNA Mensageiro/genética , Superóxido Dismutase , Técnicas de Cultura de TecidosRESUMO
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.