Aloe vera increases mRNA expression of antioxidant enzymes in cryopreserved bovine ovarian tissue and promotes follicular growth and survival after in vitro culture.

The aims of the present study were to evaluate the effects of Aloe vera extract on expression of mRNA for antioxidant enzymes in bovine ovarian tissue after vitrification, as well as on follicular morphology, viability, activation and extracellular matrix in cultured ovarian tissues that had been previously vitrified. Fragments from bovine ovarian cortical tissue were cryopreserved in a vitrification solution alone or supplemented with two concentrations of Aloe vera (10 or 50%). After thawing, the cryopreserved tissues were analyzed by histological techniques, as well as the levels of mRNA for SOD, CAT, PRDX6 and GPX1 were investigated. Furthermore, cryopreserved fragments were then culture in vitro in α-MEM for 6 days. Histological evaluation of cultured tissues was performed to determine the percentages of normal and developing follicles. The results showed that, after vitrification, the presence of Aloe vera in both concentrations was able to maintain percentages of collagen fibers similar to fresh tissues (P < 0.05). Aloe vera in both concentrations significantly increased mRNA levels for PRDX6 and GPX1 in cryopreserved tissues, while 10% Aloe vera increased mRNA levels for SOD (P < 0.05). In parallel, after in vitro culture, fragments vitrified in the presence of 10% Aloe vera had significantly higher levels of morphologically healthy follicles when compared to tissue that were vitrified without Aloe vera. In fragments vitrified with Aloe vera, the rate of developing follicles was significantly higher than in tissues vitrified without Aloe vera. Tissues vitrified with 10% Aloe vera and cultured in vitro maintained percentages of collagen fibers similar to fresh tissues. In conclusion, 10% Aloe vera increases the expression of mRNA for PRDX6, GPX1 and SOD in vitrified ovarian tissues, maintains follicular survival and promotes activation and development of follicles after in vitro culture of vitrified bovine ovarian tissue.

Cryopreservation of Spix's yellow-toothed cavy epididymal sperm using Tris- and coconut water-based extenders supplemented with egg yolk or Aloe vera.

Addressing the establishment of biobanks for the conservation of wild hystricomorph rodents' germplasm, we verified the effects of different extenders and distinct concentrations of non-permeant cryoprotectants on the sperm parameters of Spix's yellow-toothed cavies. Nine testis-epididymis complexes were used for sperm collection by retrograde washing using Tris or a powdered coconut water extender (ACP®-116c). Spermatozoa were diluted and frozen with the same extenders supplemented with egg yolk or Aloe vera at a 10% or 20% concentration. After recovery and cryopreservation, all samples were evaluated for sperm kinetic parameters, morphology, membrane integrity, osmotic response, and sperm-binding capability using an egg yolk perivitelline membrane assay. After recovery, no differences were observed between Tris and ACP®-116c that provided 515.4 × 106 sperm/mL and 561.6 × 106 sperm/mL, presenting >65% motile sperm, respectively. After cryopreservation, most effective preservation of sperm kinetic parameters (68.1 ± 5.9% motile sperm) and membrane integrity (48.2 ± 7.4%) was provided by Tris extender supplemented with 10% egg yolk. However, both extenders supplemented with any concentration of egg yolk or Aloe vera presented similar preservation of osmotic response and sperm-binding ability after cryopreservation. In summary, we suggest the use of a Tris extender supplemented of 10% egg yolk for cryopreservation of Spix's yellow-toothed cavy epidydimal sperm.