目的 通过构建H₂O₂诱导的H9c2细胞氧化应激模型，观察人参皂苷Rg₁对氧化应激的抑制作用，并探讨miR-499c是否参与人参皂苷Rg₁抑制氧化应激的作用机制。方法 采用600 μmol/L的H₂O₂诱导H9c2细胞氧化应激模型，给予人参皂苷Rg₁预处理24 h，检测乳酸脱氢酶（lactate dehydrogenase，LDH）、超氧化物歧化酶（superoxide dismutase，SOD）活性及丙二醛（malondialdehyde，MDA）、活性氧（reactive oxygen species，ROS）水平和线粒体膜电位（mitochondrial membrane potential，MMP）变化；采用Western blotting检测凋亡相关蛋白表达。采用Lipofiter 3.0将miR-499c转染至H9c2细胞再制备H₂O₂诱导的氧化应激模型，给予人参皂苷Rg₁（40 μmol/L）预处理24 h，检测miR-499c表达、ROS水平和MMP变化。结果 人参皂苷Rg₁显著降低H₂O₂诱导的H9c2细胞中LDH漏出率、MDA和ROS水平（P<0.05、0.01、0.001），显著升高SOD活性和MMP（P<0.05、0.01、0.001），显著上调B淋巴细胞瘤-2（B-cell lymphoma-2，Bcl-2）蛋白表达水平（P<0.05、0.01、0.001），显著下调Bcl-2相关X蛋白（Bcl-2 associated X protein，Bax）、剪切型半胱氨酸天冬氨酸蛋白酶-3（cleaved cystein-asparate protease-3，cleaved Caspase-3）和cleaved Caspase-9蛋白表达水平（P<0.01、0.001）。人参皂苷Rg₁显著增加H9c2细胞中miR-499c表达（P<0.05）。转染miR-499c后，人参皂苷Rg₁组ROS水平进一步降低（P<0.05），MMP进一步升高（P<0.05）。结论 人参皂苷Rg₁通过降低MMP丢失和ROS生成，抑制由H₂O₂诱导H9c2细胞的氧化应激损伤和细胞凋亡，其作用机制可能与miR-499c相关。

Objective To observe the inhibition effect of ginsenoside Rg₁ on H₂O₂-induced oxidative stress in H9c2 cardiomyocytes, and discuss whether miR-499c involved in the mechanism of ginsenoside Rg₁ inhibition of oxidative stress. Methods The oxidative stress model of H9c2 cardiomyocytes was induced by 600 μmol/L H₂O₂, ginsenoside Rg₁ were pretreated for 24 h. Lactate dehydrogenase (LDH), superoxide dismutase (SOD) activities and malondialdehyde (MDA), reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) changes were detected; Western blotting was used to detect the expressions of apoptosis-related proteins. Lipofiter 3.0 was used to transfect miR-499c into H9c2 cells, and then H₂O₂-induced oxidative stress model was established, ginsenoside Rg₁ (40 μmol/L) was pretreated for 24 h, and miR-499c expression, ROS level and MMP changes were detected. Results Ginsenoside Rg₁ significantly decreased the leakage rate of LDH, MDA and ROS levels in H9c2 cells induced by H₂O₂ (P < 0.05, 0.01, 0.001), significantly increased SOD activity and MMP (P < 0.05, 0.01, 0.001), significantly increased B-cell lymphoma-2 (Bcl-2) protein expression level (P < 0.05, 0.01, 0.001), significantly decreased Bcl-2 associated X protein (Bax), cleaved cysteine aspartate protease-3 (cleaved Caspase-3) and cleaved Caspase-9 protein expression levels (P < 0.01, 0.001). Ginsenoside Rg₁ significantly increased the expression of miR-499c in H9c2 cells (P< 0.05). After transfection with miR-499c, the level of ROS in ginsenoside Rg₁ group was further decreased (P < 0.05), and MMP was further increased (P < 0.05). Conclusion Ginsenoside Rg₁ can inhibit oxidative stress injury and apoptosis of H9c2 cells induced by H₂O₂ by reducing MMP loss and ROS production, and its mechanism may be related to miR-499c.

R285.5

吉林省教育厅科学技术研究项目（JJKH20220533KJ）