Combined administration of catalpol, puerarin, gastrodin, and borneol modulates the Tlr4/Myd88/NF-κB signaling pathway and alleviates microglia inflammation in Alzheimer’s disease

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder affecting millions of people worldwide, with no effective treatment currently available. In recent decades, various traditional Chinese medicines (TCMs) and their active ingredients have shown the potential to attenuate the pathogenesis of AD in cellular and animal models. However, the effects of TCM formulas, which are typically administered in practice, have been less studied. This study aims to investigate the therapeutic effects of several formulas consisting of 4 components herbal components: catalpol, puerarin, gastrodin, and borneol, on streptozotocin (STZ)-induced AD models in cells and rats. The new object recognition (NOR), elevated plus maze (EMP), and Morris water maze (MWM) tests were used to evaluate the cognitive functions of rats. Golgi staining, Haematoxylin and Eosin (HE) staining, and Nissl staining analyses were employed assess the physiology of hippocampal tissues. Gene expression profiles were analyzed used transcriptomics and reverse transcription quantitative polymerase chain reaction analysis, while protein expression levels were determined using immunoblotting, immunohistochemical, and immunofluorescence. The production of cytokines was evaluated with enzyme-linked immunosorbent assay. The results demonstrated that the combined administration of these 4 components (CPGB) had superior mitigating effects on AD cell model, as evidenced by the reduced pro-inflammatory cytokine production and decreased deposition of Aβ protein. Further