Neuroinflammation plays a central role in the pathogenesis of Alzheimer’s disease (AD), with amyloid-β (Aβ) deposition and neurofibrillary tangles driving both central and peripheral inflammatory responses. This study investigated the neuroprotective and anti-inflammatory effects of Vitex trifolia (VT), Plantago major (PM), Apocyni Veneti Folium (AVF), and Eucommiae folium (EF) using network pharmacology and a co-culture model of PC12 neuronal and Caco-2 intestinal epithelial cells. Bioactive compounds were identified via high-performance liquid chromatography (HPLC) and screened with network pharmacology analysis, yielding 27 for VT, 10 for PM, 6 for AVF, and 3 for EF. Molecular docking confirmed strong binding affinities between the key bioactive compounds and AD-related targets. A co-culture system of PC12 neuronal and Caco-2 intestinal epithelial cells was established to evaluate the effects of VT, PM, AVF, and EF extracts (at concentrations of 10 µg/mL, 20 µg/mL, and 50 µg/mL) and donepezil hydrochloride (positive-control) on Aβ25–35-induced neurotoxicity and lipopolysaccharide (LPS)-induced intestinal inflammation, to assess cell viability, and effects on oxidative stress, mitochondrial function, and inflammatory markers. The VT, PM, AVF, and EF extracts activated phosphoinositide 3-kinase (PI3K)-Akt-glycogen synthase kinase-3β (GSK-3β) signaling, enhanced phosphorylation of AMP kinase, suggesting inhibition of Aβ accumulation and tau hyperphosphorylation (p < 0.05). However, donepezil hydrochloride only enhanced AMPK phosphorylation. The extracts reduced lipid peroxidation and acetylcholinesterase by about 5-fold. JC-1 staining confirmed preserved mitochondrial membrane potential, while hematoxylin and eosin staining indicated improved intestinal barrier integrity (p < 0.05). PM and AVF reduced the number of mast cells (p < 0.05). In conclusion, these findings highlight the multi-target potential of VT, PM, AVF, and EF in mitigating both neuronal and intestinal inflammation. Their dual regulatory effects on the gut–brain axis suggest promising therapeutic applications in AD through the modulation of central and peripheral immune responses.
Zhang et al. (Wed,) studied this question.