Increased oxidative stress is one of the main causes of poorly developed embryos in assisted reproductive technologies. Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production through its potent antioxidative and anti‐senescent effects. In the present study, we explored the effects of short‐term NAM‐treatment (3 and 5 h) during in vitro fertilization (IVF) on the development of bovine embryos. Treatment with 10 mM NAM for 3 h significantly increased the blastocyst formation but extending the treatment to 5 h did not enhance the benefits any further. Immunofluorescence analysis demonstrated that treatment with 10 mM NAM for 3 h decreased the expression of intracellular ROS, 8‐oxo‐7,8‐dihydroguanine, caspase‐3, and increased the expression of Sirt1, and incorporation of bromodeoxyuridine in one‐cell stage embryos. Similarly, the level of H3K56ac significantly increased in the NAM‐treated (3 and 5 h) one‐cell stage embryos. Contrastingly, the treatment with 10 mM NAM for 5 h increased the caspase‐9 level in blastocysts. Collectively, these findings suggest that NAM possesses antioxidant activity and supplementation of IVF medium with 10 mM NAM for 3 h improves the in vitro developmental competence of bovine embryos.

中文翻译：

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在体外受精培养基中添加烟酰胺对牛胚胎发育的影响。

氧化应激增加是辅助生殖技术中胚胎发育不良的主要原因之一。烟酰胺（NAM）已被证明通过其有效的抗氧化和抗衰老作用抑制活性氧（ROS）的产生。在本研究中，我们探讨了体外受精 (IVF) 期间短期 NAM 治疗（3 和 5 小时）对牛胚胎发育的影响。用 10 mM NAM 处理 3 小时显着增加了囊胚形成，但将处理延长至 5 小时并没有进一步提高益处。免疫荧光分析表明，用 10 mM NAM 处理 3 小时可降低细胞内 ROS、8-oxo-7,8-二氢鸟嘌呤、caspase-3 的表达，并增加 Sirt1 的表达，以及单细胞阶段胚胎中溴脱氧尿苷的掺入. 同样，在 NAM 处理的（3 和 5 小时）单细胞期胚胎中，H3K56ac 的水平显着增加。相比之下，用 10 mM NAM 处理 5 小时会增加囊胚中的 caspase-9 水平。总的来说，这些发现表明 NAM 具有抗氧化活性，在体外受精培养基中添加 10 mM NAM 3 小时可提高牛胚胎的体外发育能力。