Protective Effects of Astragaloside IV on Hypoxia/Reoxygenation-Induced H9c2 Cell Injury: Mitochondrial Function and Nrf2/HO-1 Signaling.

Abstract

Myocardial ischemia-reperfusion injury is closely associated with oxidative stress and mitochondrial dysfunction. Astragaloside IV (ASIV), a major bioactive component of Astragalus membranaceus, has been reported to exert cardiovascular protective effects. The present study investigated the protective effects of ASIV against hypoxia/reoxygenation (H/R)-induced injury in H9c2 cells, with particular attention to mitochondrial function, oxidative stress, and Nrf2/HO-1 signaling. H9c2 cells were subjected to 12 h of hypoxia followed by 16 h of reoxygenation. Cells were pretreated with ASIV before H/R exposure. Cell viability was assessed using the CCK-8 assay. Intracellular ROS levels, SOD activity, and MDA content were evaluated to assess oxidative stress. Mitochondrial respiratory function was examined using the extracellular flux analyzer, and mitochondrial membrane potential was evaluated using JC-1. The expression of apoptosis-related proteins and proteins associated with Nrf2/HO-1 signaling was analyzed by Western blotting. H/R exposure reduced H9c2 cell viability, increased intracellular ROS levels and MDA content, decreased SOD activity, and impaired mitochondrial function. ASIV pretreatment attenuated these H/R-induced alterations. ASIV also improved mitochondrial respiratory parameters and partially restored mitochondrial membrane potential. Changes in apoptosis-related protein expression were consistent with attenuation of H/R-induced pro-apoptotic signaling. In addition, ASIV pretreatment was accompanied by changes in Nrf2 and HO-1 expression, suggesting an association between the protective effects of ASIV and Nrf2/HO-1 signaling. ASIV pretreatment attenuated H/R-induced injury in H9c2 cells, accompanied by reduced oxidative stress and preservation of mitochondrial function. The observed protective effects were associated with changes in Nrf2/HO-1 signaling. Further pathway-specific studies are required to determine whether Nrf2/HO-1 signaling is causally involved in the protective effects of ASIV.

Key Findings

• Astragaloside IV (ASIV) pretreatment attenuated hypoxia/reoxygenation-induced injury in H9c2 cells by reducing oxidative stress markers such as intracellular ROS and MDA levels.
• ASIV improved mitochondrial function, including respiratory parameters and mitochondrial membrane potential, which were impaired by hypoxia/reoxygenation.
• Protective effects of ASIV were associated with modulation of Nrf2/HO-1 signaling and reduced pro-apoptotic protein expression.

Clinical Significance

Citation

Zhou Liurong, Tan Lihua, Huang Yuet al.. Protective Effects of Astragaloside IV on Hypoxia/Reoxygenation-Induced H9c2 Cell Injury: Mitochondrial Function and Nrf2/HO-1 Signaling. Journal of visualized experiments : JoVE. 2026-Oct-23.