Isoorientin Promotes Early Porcine Embryonic Development by Alleviating Oxidative Stress and Improving Lipid Metabolism

Isoorientin (ISO) is a natural lignan glycoside flavonoid found in various plants, including Charcot and Stonecrop. ISO exhibits diverse physiological and pharmacological effects, such as antioxidative, anti-inflammatory, hepatoprotective, antiviral, antianxiety, and anti-myocardial ischaemic properties, as well as lipid metabolism regulation. This study investigated the impact of ISO supplementation on oxidative stress and lipid accumulation in porcine early embryos, along with its underlying mechanisms. Porcine embryos were cultured in vitro under different concentrations of ISO (0, 1, 10, and 100 nM). The results revealed that 10 nM ISO significantly enhanced the blastocyst rate and total embryonic cell count in vitro. ISO-treated embryos exhibited reduced reactive oxygen species levels and elevated glutathione levels compared to the untreated group. In addition, ISO treatment significantly increased the expression of the key antioxidant regulator Nrf2, improved mitochondrial function, and reduced lipid droplet accumulation. Concurrently, early embryo autophagy and apoptosis levels decreased. Furthermore, ISO treatment upregulated antioxidant-related genes (<i>SOD1, SOD2,</i> and <i>CAT</i>) and mitochondrial biogenesis related genes (<i>NRF1</i>, <i>NRF2,</i> and <i>SIRT1</i>), while downregulating lipid synthesis-related genes (<i>SREBP1</i> and <i>FASN</i>). Additionally, lipid hydrolysis-related genes (<i>ACADS</i>) were elevated. These findings collectively suggest that ISO may facilitate early embryonic development in pigs by ameliorating oxidative stress and lipid metabolism.