A study on the potential mechanism of key components of panax notoginseng in treating brain injury by network pharmacology combined with molecular docking technique
Authors: Zhang Guodong , Zhang Jiaqi , Li Yuanchao , Shi Pengqiang , Lu Gui , Li Yingyue , Cheng Zhenguo , Zhang Jianhua 
Published: February 2024

Abstract
Objective To investigate the effect and molecular mechanism of panax notoginseng on brain injury by network pharmacology, molecular docking and biological experiments.
Method TCMSP database was used to analyze the major active ingredients of panax notoginseng. LC-MS was employed for quantitative analysis of quercetin content in panax notoginseng. The potential targets of panax notoginseng components interfering with craniocranial injury were analyzed by network pharmacology, and the function and signal pathway of potential targets were enriched and analyzed. Protein interaction networks of potential targets were constructed, core targets were screened, active components corresponding to core targets were analyzed in reverse, and key active components and their targets were screened for vina software molecular docking and subsequent experimental verification. The TBI cell model was constructed, and the effect of quercetin on the activity of the TBI cell model was detected by CCK-8 method, the effect of quercetin on the apoptosis of the TBI cell model was detected by flow cytometry, and the effect of quercetin on the mRNA and protein expression levels of the key targets in the TBI cell model was detected by QPCR and western blot. Finally, the signaling pathway of quercetin improving traumatic brain injury was constructed.
Results Panax notoginseng mainly contained 9 components, a total of 333 potential targets were obtained, and 290 targets were combined with craniocerebral injury. In enrichment analysis, 10 potential targets were found in GO and KEGG signaling pathways respectively. The TOP10 core targets in the protein interaction network were CASR, APP, PIK3CA, PIK3R1, F2, S1PR1, ADORA1, ADORA3, DRD2 and CNR1.According to the number and order of corresponding core targets, quercetin was selected for molecular docking and subsequent experimental verification. Molecular docking showed that the binding energies of quercetin and corresponding targets APP, F2 and PIK3R1 were -7.7 kcal/mol, -7.3 kcal/mol and -8.4 kcal/mol, forming 2, 1 and 5 hydrogen bonds, respectively. It can be seen that quercetin and APP, F2, PIK3R1 all showed good binding activity. Quercetin experiment results showed that 0, 0.1, 0.3, 1, 3, 10 μM quercetin treated TBI cells, the cell activity increased significantly (65.1%±2.2%, 77.7%±5.3%, 87.4%±1.5%, 96.4%±0.4%, 93.6%±3.5%), and showed concentration dependence. Flow cytometry was used to detect the apoptosis of TBI cells in control group, TBI group, low concentration and high concentration groups. The results showed that the apoptosis rates of the four groups were 11.85%, 30.64%, 19.76% and 14.21%, respectively. The expression level of APP (mRNA and protein) in the TBI model cells treated with quercetin was significantly decreased, and the expression level in the high-dose group was significantly lower than that in the low-dose group, while the expression of PIK3R and F2 was the opposite.
Conclusion Quercetin, the component of pantoginseng, has a certain protective effect on brain injury cells, and it may regulate the related signaling pathways by interfering with APP, PIK3R and F2, and play a role in the protection and improvement of brain injury.