Paeoniflorin Improves Stroke by Modulating the ESR1 Pathway: Data Mining and Validation Based on Network Approaches

<b><i>Aim of the study:</i></b> Traditional Chinese herbs have a unique therapeutic effect on stroke and numerous successful clinical cases. However, these clinical cases are highly dispersed, creating challenges for translational research. This study employs a new paradigm to identify treatment patterns and the active compound interactions contained within these clinical cases, with experimental validation after target screening. <b><i>Methods and Materials:</i></b> Stroke-related targets were identified through GEO, DisGeNET, and Genecards. Active ingredients were extracted from BATMAN-TCM 2.0. All herbs and diseases were confirmed by the Pharmacopoeia of the People's Republic of China (2020 edition) and Medical Subject Heading (MeSH). All networks in this study were constructed by Cytoscape, and data analysis was done by Python. All formulations and herbs were retrieved from the literature review. For the molecular docking process, Autodock was applied as the docking platform, and all the protein structures were downloaded from PDB. For experimental validation after target screening, HT22 cells were incubated with glucose-free DMEM and placed in an anaerobic chamber for 2 h. Subsequently, HT22 cells were reoxygenated for 24 h. Estrogen Receptor 1 (ESR1) protein levels were measured in vitro. <b><i>Results:</i></b> seven materials, including Angelicae Sinensis Radix, Pheretima, Chuanxiong Rhizoma, Persicae Semen, Astragali Radix, Carthami Flos, and Radix Paeoniae Rubra, were identified as the core herbs for the treatment of stroke. The targets of the stroke mechanism were screened, and the herbs-compound-target network was constructed. Among them, paeoniflorin (PF) was identified as the core active compound, and its interaction with ESR1 was verified by molecular docking as the key interaction for the treatment of stroke. In vitro experiments showed that PF inhibited cell apoptosis under hypoxia by increasing the expression of ESR1 compared with the oxygen-glucose deprivation-reperfusion (OGD/R) model group. Western showed that PF (100 μM, 200 μM) can significantly increase the decreased ESR1 protein level caused by the OGD/R model. <b><i>Conclusions:</i></b> seven key herbs were screened. Further bioinformatics and network pharmacology studies suggested that PF is expected to become a new active compound for the treatment of stroke. In vitro validation further demonstrated that PF enhanced neuronal survival and ESR1 expression under ischemic conditions, supporting its therapeutic candidacy.