Freeze–thaw induced genotoxicity in buffalo (Bubalus bubalis) spermatozoa in relation to total antioxidant status

Abstract

Use of cryopreserved semen has become an important tool in assisted reproduction but freezing and thawing cause sub-lethal damage to spermatozoa. This is detrimental to sperm because of the membrane damage including permeability and integrity. An excess generation of reactive oxygen species (ROS) creates oxidative stress due to reduced antioxidant status of the cryopreserved spermatozoa. In the present study fresh buffalo semen was collected and divided into two aliquots. One aliquot was used for fresh semen analysis and the other was cryopreserved in Tris-egg yolk-citrate extender. The semen samples were used to study different sperm quality parameters like motility, viability, membrane integrity and total antioxidant status. The DNA integrity in fresh and cryopreserved spermatozoa was also studied using comet assay. The sperm quality parameters like post-thaw sperm motility, viability, membrane integrity and total antioxidant status of cryopreserved spermatozoa were significantly lowered (P < 0.05) compared to fresh spermatozoa. The DNA fragmentation in cryopreserved spermatozoa was significantly higher (P < 0.01) as compared to fresh spermatozoa. The results show that the irreversible DNA damage occurs in spermatozoa during cryopreservation.

Apoptosis, ROS and Calcium Signaling in Human Spermatozoa: Relationship to Infertility

“…After cryopreservation and thawing or centrifugation, an excess of ROS is detected evoking oxidative stress in germ cells due to lowered intracellular antioxidant levels. As expected, these effects cause irreversible damage to DNA (Agarwal et al, 1994;Kumar et al, 2011). In this regard, the application of antioxidants appears as a tool to protect germ cells from manipulation-induced oxidative damage.…”

Melatonin diminishes oxidative damage in sperm cells,improving assisted reproductive techniques

“…These effects produce irreversible damage to DNA (Kumar et al, 2011). Furthermore, during the performance of semen preparation techniques, the natural protection against oxidative threats is removed.…”

Estrés oxidativo: ¿un estado celular defectuoso para la función espermática?

“…La manipulación, criopreservación y descongelación o centrifugación de las muestras seminales durante los procedimientos de rutina en los laboratorios de reproducción asistida, promueven la producción de ROS y la eliminación de gran parte de los antioxidantes extracelulares, lo cual genera efectos no deseados sobre las células germinales (65,66). Beneficios y riesgos de la terapia antioxidante en el manejo de la infertilidad.…”