The pathological and physiological studies of Alzheimer’s disease (AD) have been in-depth, and apolipoprotein E4 (ApoE4) has been proven to be highly correlated with AD, and clinical and experimental data show that ApoE4 can cause blood–brain barrier (BBB) injury, and the change of BBB permeability is an important factor affecting the development of AD. Andrographolide (Andro), as the active component of the natural plant Andrographis paniculata , has been proven to have anti-inflammatory and antioxidant effects, which have potential neuroprotective effects. To verify the protective effect of Andro on BBB in a short term, our research group used atorvastatin (Atorva)-mediated zebrafish brain injury model and the ApoE4-mediated cell co-culture model of BBB injury to explore the protective effects and mechanisms of Andro on BBB injury. Studies have shown that Andro can inhibit the activation of CypA/NF-κB/MMP-9 signaling pathway and has achieved the effect of antagonizing the inhibition of ApoE4 on intercellular tight junction proteins (occludin, claudin-5, and ZO-1). At the same time, Andro can inhibit the secretion of cell adhesion molecules (VCAM-1 and ICAM-1) in cells, thereby delaying the occurrence and progression of neuroinflammation and playing a protective role in BBB. In conclusion, Andro is a potent natural product which can protect the blood–brain barrier.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized primarily by deterioration in memory, cognition, and learning ability. Its etiology is complex and influenced by multiple factors, including genetics and environment. With advancing research into mitochondrial function and mechanisms, impaired mitophagy has been proposed as a significant mechanism contributing to AD. The ApoE ε4 allele, a high-risk genetic factor for AD, may play a key role in disease pathogenesis by inducing mitophagy dysfunction and apoptosis. From the perspective of APOE gene polymorphisms, this study investigates abnormal changes in mitochondrial function and autophagy in humanized APOE4 mice primary astrocytes under oxidative stress, as well as the regulatory effect of curcumin (Cur) on mitophagy and oxidative stress-induced apoptosis, thereby exploring its potential to ameliorate AD through targeting mitophagy. Mitochondrial function analysis revealed that APOE4 expression reduced the antioxidant capacity and respiratory function of primary astrocytes, leading to mitochondrial membrane damage, intracellular reactive oxygen species (ROS) accumulation, and decreased ATP production. Curcumin effectively protected mitochondrial integrity, reduced the number of damaged mitochondria, improved overall mitochondrial function, and helped maintain mitochondrial homeostasis involving in PINK1/Parkin pathway. Regarding autophagy and apoptosis, curcumin was shown to restore autophagic flux, mitigate autophagy disruption caused by oxidative stress, and reverse early-stage apoptosis. Graphical