Effect of autologous platelet-rich plasma on the fertility and quality of cryopreserved buffalo bull semen: a comparative study using OptiXcell® and tris egg yolk extenders

Abstract

Background: Buffalo spermatozoa have a distinct membrane structure that makes them more vulnerable to cryopreservation, resulting in lower-quality post-thawed sperm. This decreases the success rate of artificial insemination in buffaloes. Understanding and addressing these specific vulnerabilities are essential for improving reproductive techniques in buffalo populations. The properties of cryopreserved buffalo bull semen were examined in this study regarding the impact of adding autologous platelet-rich plasma (PRP) to OptiXcell® or Tris egg yolk-based extenders. Ten buffalo bulls were used to collect semen. Each bull's ejaculate was separated into two main equal amounts, each of which was then diluted with either OptiXcell® or Tris egg yolk-based extender, supplemented with various PRP concentrations (5%, 10%, and 15%), and the control (0%), before being cryopreserved according to established protocols. Following equilibration and thawing, the quality and functionality of the sperm were evaluated, along with the antioxidant enzyme activities (GSH and TAC), malondialdehyde (MDA) content, and in vivo fertilization rate of the thawed semen.

Results: All PRP concentrations in both extenders, particularly 10% PRP, improved the quality and functionality of the sperm in both equilibrated and frozen-thawed semen. Additionally, the antioxidant enzyme activities in both extenders were higher in the PRP-supplemented groups compared to the control group in thawed semen (P < 0.05). All post-thaw sperm quality, antioxidant enzyme activities, and functionality aside from DNA integrity were higher (P < 0.05) in the PRP-supplemented OptiXcell® than in the PRP-supplemented Tris egg yolk-based extender. The fertility of cryopreserved semen in the extenders supplemented with 10% and 15% PRP increased (P < 0.05) significantly more than that of the control extenders, with 10% PRP being the optimum concentration in OptiXcell® (80%) compared to that of Tris egg yolk-based extender (66.67%) and control of two extenders (53.33% and 46.67%, respectively).

Conclusions: Even though autologous PRP-supplemented extenders have a protective impact on equilibrated and cryopreserved semen, 10% PRP-supplemented OptiXcell® extenders are more effective at preserving post-thaw semen quality, functionality, and antioxidant capacity, which increases the in vivo fertility of buffalo bulls.

Keywords: Buffalo bull semen; In vivo fertilization; OptiXcell® extender; Platelet-rich plasma; Tris egg yolk-based extender.

Fig. 1

Images illustrating the quality and functionality of sperm. Figure 1. Panel A: Sperm viability: The red arrow indicates live sperm, and the white arrow indicates dead sperm. Panel B: Sperm abnormality: The red arrow indicates normal sperm, the blue arrow indicates a lobed tail, the green arrow indicates a coiled tail, the black arrow indicates a detached head, and the white arrow indicates a bent tail. Panel C: Acrosome integrity: The red arrow indicates an intact acrosome, the white arrow indicates a vacuolated acrosome, and the green arrow indicates a ruptured acrosome. Panel D: Membrane integrity: The red arrow indicates HOST-positive and the white arrow indicates HOST-negative. Panel E: Mitochondrial activity: The red arrow indicates high mitochondrial membrane potential (MMP), and the white arrow indicates low MMP. Panel F: DNA fragmentation: The red arrow indicates intact DNA, and the white arrow indicates a damaged DNA