Protective effect of 18β-glycyrrhetinic acid against H(2)O(2)-induced injury in Schwann cells based on network pharmacology and experimental validation

The aim of the present study was to assess the protective effects of 18β-GA against hydrogen peroxide (H(2)O(2))-induced injury. First, the SMILES annotation for 18β-GA was used to search PubChem and for reverse molecular docking in Swiss Target Prediction, the Similarity Ensemble Approach Search Server and the TargetNet database to obtain potential targets. Injury-related molecules were obtained from the GeneCards database and the predicted targets of 18β-GA for injury treatment were selected by Wayne diagram analysis. Subsequently, Kyoto Encyclopedia of Genes and Genomes analysis was performed by WebGestalt. The experimental cells were assorted into control, model, 10 µM SB203580-treated, 5 µM 18β-GA-treated and 10 µM 18β-GA-treated groups. Hoechst 33258 staining was performed and intracellular reactive oxygen species (ROS) levels, cell apoptosis, Bcl-xl, Bcl-2, Bad, Bax, cleaved-caspase 3, cleaved-caspase 7, transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential vanilloid 1 (TRPV1) levels, as well as p38 MAPK phosphorylation were measured. The ‘Inflammatory mediator regulation of TRP channels’ pathway was selected for experimental verification. The results indicated that 10 µM 18β-GA significantly increased cell viability as compared with the H(2)O(2)-treated model group. As suggested by the difference in intracellular ROS fluorescence intensity, 18β-GA inhibited H(2)O(2)-induced ROS production in Schwann cells. Hoechst 33258 staining indicated that 18β-GA reversed chromatin condensation and the increase in apoptotic nuclei following H(2)O(2) treatment. Furthermore, flow cytometry suggested that 18β-GA substantially inhibited H(2)O(2)-induced apoptosis. Pre-treatment with 18β-GA obviously reduced Bad, Bax, cleaved-caspase3, cleaved-caspase 7, TRPA1 and TRPV1 levels and p38 MAPK phosphorylation after H(2)O(2) treatment and increased Bcl-2 and Bcl-xl levels. In conclusion, 18β-GA inhibited Schwann cell injury and apoptosis induced by H(2)O(2) and may be a potential drug to prevent peripheral nerve injury.