Antihyaluronidase Action of Ellagic Acid Effectively Prevents Polyspermy As a Result of Suppression of the Acrosome Reaction Induced by Sperm-Zona Interaction During In Vitro Fertilization of Porcine Oocytes

Abstract

Abstract. The present study was conducted to examine the effects of three tannin relatives (tannic acid, TA; gallic acid, GA; and ellagic acid, EA) on antihyaluronidase and reactive oxygen species (ROS) scavenging activity, in vitro fertilization (IVF) parameters, and the acrosome reaction (AR) induced by sperm-zona interaction. Among the three tannin relatives, TA and EA showed the strongest potency for blocking the hyaluronidase activity of boar sperm, with concentrationdependent inhibition over the range of 2-10 µg/ml. In contrast, ROSs were effectively scavenged by TA and GA, but not EA. When cumulus-free oocytes were inseminated in IVF medium containing 5 µg/ml of the tannin relatives, polyspermy was significantly reduced by TA and EA (32 and 29%, respectively) compared with oocytes treated with or without GA (51 and 69%, respectively) under conditions that maintained a high sperm penetration rate (P<0.05). Interestingly, induction of the AR by treatment of preincubated sperm with progesterone was blocked by TA and GA as a result of their higher levels of ROS scavenging activity, while EA, which possessed weak ROS scavenging activity, did not disturb induction of the AR with progesterone. However, the incidence of AR induced by sperm-zona interaction was significantly decreased by the strong antihyaluronidase actions of TA and EA compared with that in the absence of these compounds. Treatment with the compounds caused neither a protective proteolytic modification of the zona pellucida matrix before fertilization nor a reduction in acrosomal proteolytic activity or the number of zona-bound sperm. These findings suggest that the antihyaluronidase action of EA effectively prevents polyspermy by suppression of AR functionality induced by sperm-zona interaction and that hyaluronidase intervention is therefore required during porcine IVF.

Melatonin and tannic acid supplementation in vitro improve fertilization and embryonic development in pigs

“…Tannic acid has antihyaluronidase activity and scavenges ROS in boar sperm, which has shown to improve IVF in pigs (Tokeshi et al, 2007). Our results were similar, as supplementation of tannic acid to the fertilization media decreases polyspermic penetration regardless if melatonin was supplemented during maturation.…”

Role of Acidification Elicited by Sialylation and Sulfation of Zona Glycoproteins During Oocyte Maturation in Porcine Sperm-zona Pellucida Interactions

“…Therefore, in the present study, it is likely that the sulfation block of ZP glycoproteins had a specific influence on the secondary binding of AR sperm to the ZP during the initial stages of fertilization, thus resulting in a decrease in polyspermic fertilization. We also clearly demonstrated that the suppression of AR functionality induced by sperm-ZP interactions through the antihyaluronidase action of ellagic acid effectively prevented polyspermy with no effect on sperm penetration during porcine IVF [37]. However, further studies are needed to identify the precise mechanism in sperm-ZP interactions relating to polyspermic fertilization because the interactions between the sperm and the ZP are mediated by a complex involving several sperm plasma membrane proteins and several carbohydrates contained in the ZP [5][6][7][8] and the modifications of ZP glycans responsible for sperm AR induction are established by glycosylation, sulfation, sialylation and fucosylation during oocyte growth and maturation [38].…”

Pre-incubation of porcine semen reduces the incidence of polyspermy on embryos derived from low quality oocytes

“…So, as alternative to obtain an efficient IVP of porcine embryo is to search for protocol adaptations so that good rates of embryo development could be achieved, even when using low quality oocytes. A key factor for the low efficiency of IVP porcine embryos is the high rate of polyspermy (TOKESHI et al, 2007), which is directly associated to the amount of sperm at the site of fertilization (FAUSTINI et al, 2010), and also the oocytes quality (SUZUKI et al, 2003). When several spermatozoa penetrate the oocyte, the DNA de-condensation is difficult, probably due to intense competition for factors involved in the process of pronucleus formation (COY et al, 1993b).…”

“…However, the porcine in vitro embryo development is still lower than the in vivo (KWAK et al, 2014). One of the determining factors for the low efficiency of porcine embryo IVP is the elevated rate of polyspermy (TOKESHI et al, 2007;FAUSTINI et al, 2010). Great variations have been observed in polyspermy rates of both fresh (SIRARD et al, 1993) and frozen semen (NAGAI et al, 1988).…”