Qifu-yin activates the Keap1/Nrf2/ARE signaling and ameliorates synaptic injury and oxidative stress in APP/PS1 mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional medicinal formulation, Qifu-yin (QFY), has been widely prescribed for Alzheimer's disease (AD) treatment in China, yet the comprehensive mechanisms through which QFY mitigates AD pathology remain to be fully delineated. AIM OF THE STUDY: This study aimed to explore the therapeutic implications of QFY on the synaptic injury and oxidative stress in the hippocampus of APPswe/PS1dE9 (APP/PS1) mice, with a concerted effort to elucidate the molecular mechanisms related to synaptic preservation and memory improvement. MATERIALS AND METHODS: The components of QFY were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The neuroprotective effects of QFY was evaluated using six-month-old male APP/PS1 mice. Subsequent to a 15 days of QFY regimen, spatial memory was assessed utilizing the Morris water maze (MWM) test. Amyloid-beta (Aß) aggregation was detected via immunostaining, while the quantification of Aß1-40 and Aß1-42 was achieved through enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy (TEM) was used to investigate the synaptic structure and mitochondrial morphology. Golgi staining was applied to examine dendritic spine density. Reactive oxygen species (ROS), 3-nitrotyrosine (3-NT) and 4-hydroxy-nonenal (4-HNE) assays were employed to assess oxidative stress. The expression profiles of Aß metabolism-associated enzymes and the Keap1/Nrf2/ARE signaling pathway were determined by Western blot. RESULTS: A total of 20 principal compounds in QFY were identified. QFY mitigated memory deficits of APP/PS1 mice, including reducing escape latency and search distance and increasing the time and distance spent in the target quadrant. In addition, QFY increased platform crossings of APP/PS1 mice in the probe trial of MWM tests. TEM analysis showed that QFY increased synapse number in the CA1 region of APP/PS1 mice. Further studies indicated that QFY elevated the expression levels of Post synaptic density protein 95 (PSD95) and synaptophysin, and mitigated the loss of dendritic spine density in the hippocampus of APP/PS1 mice. QFY has been shown to ameliorated the structural abnormalities of mitochondria, including mitochondrial dissolution and degradation, up-regulate ATP synthesis and membrane potential in the hippocampus of APP/PS1 mice. Moreover, QFY activated the Keap1/Nrf2/ARE signaling pathway in the hippocampus of APP/PS1 mice, which might contribute to the neuroprotective effects of QFY. CONCLUSION: QFY activates the Keap1/Nrf2/ARE signaling, and protects against synaptic and mitochondrial dysfunction in APP/PS1 mice, proposing a potential alternative therapeutic strategy for AD management.

Protective Effect of Compound Tongluo Decoction on Brain Vascular Endothelial Cells after Ischemia-Reperfusion by Inhibition of Ferroptosis Through Regulating Nrf2/ARE/SLC7A11 Signaling Pathway.

Cerebral infarction is one of the most common diseases for aged people. Compound Tongluo Decoction (CTLD), a classic traditional Chinese Medicine prescription, has been widely used in the treatment of ischemic cerebral infarction. Transient middle cerebral artery occlusion (tMCAO) rat model is established for the animal experiment and oxygen-glucose deprivation and reperfusion (OGD/R) human umbilical vein endothelial cells (HUVECs) model are established for the cell experiment. This also use Nrf2-/- rats to detect the role of nuclear factor erythroid 2-related factor 2 (Nrf2). Longa score, Evans blue staining, brain water content measurement, and histological observation are done. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and other ferroptosis-related components are detected respectively. In the vivo experiment, CTLD relieved ischemia-reperfusion (IR) injury symptoms and attenuated IR injury in brain tissues of tMCAO rats by relieving peroxidation injury in brain tissues and inhibiting ferroptosis in tMCAO rats. Moreover, CTLD reversed OGD/R-induced oxidative damage of endothelial cells via suppressing ferroptosis. After knocking out the Nrf2 gene, the protective effect of CTLD is sharply reduced. This study put forward that CTLD can inhibit ferroptosis in I/R-injured vascular endothelium by regulating Nrf2/ARE/SLC7A11 signaling to improve the relative symptoms of rats after cerebral I/R injury, thus providing a viable treatment option for cerebrovascular disease.