Faculty of Agriculture, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.
Faculty of Agriculture, Saga University, Saga, Saga city, 840-8502, Japan.
Theriogenology. 2024 Feb;215:95-102. doi: 10.1016/j.theriogenology.2023.11.021. Epub 2023 Nov 22.
The present study investigated the effects of ellagic acid, a type of polyphenol that does not have a glycan and is composed of four hydroxyl groups and two lactone functional groups, on porcine in vitro fertilization (IVF) by focusing on its anti-hyaluronidase activity. A comparative analysis of ellagic acid and apigenin, which is commonly used as a hyaluronidase inhibitor, was performed. It compared the effects of ellagic acid and apigenin on hyaluronidase activity at different concentrations. The results showed that 10, 20, and 40 μM ellagic acid strongly reduced hyaluronidase activity (P < 0.05). The addition of 20 μM ellagic acid, but not apigenin, to porcine IVF medium effectively reduced polyspermy without decreasing sperm penetration or the formation rates of male pronuclei in cumulus-free oocytes. However, neither ellagic acid nor apigenin affected the number of sperm that bound to zona pellucida (ZP) or the induction of zona hardening and protease resistance. The percentage of acrosome-reacting sperm that bound to the ZP was markedly lower in the presence of 20 μM ellagic acid than in the untreated and apigenin-treated groups, even though the antioxidant capacity of ellagic acid was weaker than that of apigenin. Furthermore, a markedly higher percentage of embryos developed to the blastocyst stage in the ellagic acid-treated group, and the apoptotic indexes of expanded blastocysts produced by the ellagic acid treatment during IVF were significantly low. Therefore, the anti-hyaluronidase effect of ellagic acid markedly suppressed the induction of the acrosome reaction in sperm that bound to the ZP, resulting in a marked decrease in polyspermy under conditions that maintained high sperm penetrability during IVF and sustainment of the developmental potency in porcine oocytes.
本研究通过关注其抗透明质酸酶活性，研究了鞣花酸（一种不含聚糖且由四个羟基和两个内酯官能团组成的多酚）对猪体外受精（IVF）的影响。对鞣花酸和常用的透明质酸酶抑制剂芹菜素进行了比较分析。比较了不同浓度下鞣花酸和芹菜素对透明质酸酶活性的影响。结果表明，10、20 和 40μM 鞣花酸强烈降低透明质酸酶活性（P<0.05）。向猪 IVF 培养基中添加 20μM 鞣花酸而不是芹菜素可有效降低多精受精，而不会降低精子穿透或无卵丘卵母细胞中雄性原核的形成率。然而，鞣花酸和芹菜素均不影响与透明带（ZP）结合的精子数量，也不诱导透明带变硬和蛋白酶抗性。与未处理组和芹菜素处理组相比，在存在 20μM 鞣花酸的情况下，与 ZP 结合的顶体反应精子的百分比明显更低，尽管鞣花酸的抗氧化能力弱于芹菜素。此外，在鞣花酸处理组中，胚胎明显更多地发育到囊胚阶段，并且在 IVF 期间用鞣花酸处理产生的扩展囊胚的凋亡指数明显较低。因此，鞣花酸的抗透明质酸酶作用显著抑制了与 ZP 结合的精子顶体反应的诱导，从而在保持 IVF 期间高精子穿透性的条件下，显著降低多精受精，并维持猪卵母细胞的发育潜能。
