Exploration on mechanism of Polygalae Radix and Acori Tatarinowii Rhizoma in treating Alzheimer's disease based on network pharmacology and experimental verification

Abstract

This study aimed to explore the action targets and mechanisms of Polygala tenuifolia and Acorus tatarinowii in treating Alzheimer's disease(AD) based on network pharmacology, molecular docking, and animal tests. The AD-related targets were collec-ted from GeneCard and the main active ingredients and targets of P. tenuifolia and A. tatarinowii from the TCMSP. Cytoscape was applied to construct the "Chinese herb-active ingredient-target-disease" network, followed by the construction of protein-protein interaction(PPI) network using STRING. GO biological function and KEGG pathway enrichment analysis was performed by DAVID and Metascape. The main active components of P. tenuifolia and A. tatarinowii and their potential core targets were docking using AutoDock Vina. The effects of P. tenuifolia and A. tatarinowii on the cognitive function were verified in mice with scopolamine(SCOP)-induced cognitive impairment. A total of seven active ingredients including kaempferol, onjixanthone Ⅰ, and marmesin and 56 potential targets of P. tenuifolia and A. tatarinowii were screened out, with the core targets covering AKT1, PTGS2, TNF, and NF-κB inflammation pathway mainly involved. The results of molecular docking also showed that the main active components of P. tenuifolia and A. tatarinowii stably bond to the core targets predicted by network pharmacology. The new object recognition experiment suggested that P. tenuifolia and A. tatarinowii improved the learning and memory abilities of mice after SCOP induction. As revealed by pathological section observation and relevant kit assay, P. tenuifolia and A. tatarinowii reduced the damage of central cholinergic neurons and enhanced the antioxidant ability of SCOP-induced mice. Western blot confirmed that P. tenuifolia and A. tatarinowii down-regulated the protein expression levels of TLR4, NF-κB, and related inflammatory factors(TNF-α, IL-1β, and IL-6). All these have suggested that P. tenuifolia and A. tatarinowii inhibits AD via multiple components, multiple targets, and multiple pathways, which has provided an experimental basis for the clinical application of P. tenuifolia and A. tatarinowii for the treatment of AD.