Isodon suzhouensis from Suzhou, China, is a traditional Chinese herb with wide applications in medicine and food. The antioxidant activity against oxidative stress of the leaves of Isodon suzhouensis is a myth since long and is not explored earlier thoroughly. The present study is focused to explore the active components in Isodon suzhouensis leaf extracts responsible for antioxidant effects against oxidative stress and the potential mechanism of this activity. We obtained the chromatograms of Isodon suzhouensis leaf extracts by the high-performance liquid phase (HPLC) for possible detection of antioxidant constituents. Some compounds in Isodon suzhouensis leaf extracts were then further assessed through the luminol luminescence mechanism combined with HPLC analysis as well as with SwissTargetPrediction database that helped to screen out the other constituents. The targets for effects against oxidative stress were then further screened through the GeneCards database, and the PPI network was constructed. The targets were analyzed by GO and KEGG using the David database. The obtained results were then further studied by employing in vitro experimentation and protein expression analyses by Western blotting. It is found that Isodon suzhouensis leaf extracts contain rutin, isoquercetin, glaucocalyxin A, glaucocalyxin B, and other compounds with antioxidant activity. The activity map of the free radical scavenging signals from Isodon suzhouensis showed a strong ability to scavenge free radicals with the highest capacity of glaucocalyxin B followed by isoquercetin succeeding the glaucocalyxin A supervening the rutin. Further network pharmacological analyses and in vitro experimentation showed that Isodon suzhouensis leaf extracts interfere with TNF and the p38 MAPK signaling pathway for antioxidant effects against oxidative stress. Conclusively, it is found that Isodon suzhouensis leaf extracts possess strong antioxidant potential via targeting TNF and p38 MAPK signaling pathways against oxidative stress, providing scientific foundation for further studies on Isodon suzhouensis for the further therapeutic approach.
Background Diabetic kidney disease (DKD) is one of the major chronic microvascular complications of diabetes and the main cause of end-stage renal failure. Zhenwu Decoction (ZWD), an ancient classic herbal formula in Chinese medicine, has been clinically used for the treatment of kidney disease in China for many years. However, there is currently limited research investigating the application of ZWD in the treatment of DKD and the underlying chemical and biochemical mechanisms involved. Therefore, in the present study, we aimed to identify active components in ZWD and unravel the possible mechanism(s) of action for ZWD in treating DKD. Methods The protective effect of ZWD against DKD was evaluated utilizing an in vitro model of diabetic renal proximal tubulopathy. The major chemical components from ZWD were identified by LC-MS/MS. Drug targets were predicted by submitting the SMILES (Simplified Molecular Input Line Entry System) of the compounds to SEA (Similarity Ensemble Approach) search server and SwissTargetPrediction. The differentially expressed genes (DEGs) of the disease were collected and integrated from GeneCards. The constructions of “Compounds-potential targets interaction” (CTI) network and Protein-Protein Interaction (PPI) network, as well as topology analysis were conducted by Cytoscape. Gene Ontology (GO)-enrichment and Metacore pathway enrichment analysis were also performed. Lastly, molecular docking and experimental studies were adopted to validate the core target and identify an active component(s) of ZWD. Results We demonstrated that the ZWD extract could significantly rescue the palmitic acid (PA) and high glucose-induced apoptotic cell death in HK-2 cells, and the cytoprotection was accompanied by decreases in the extent of reactive oxygen species (ROS) production, mitochondrial membrane depolarization and ATP depletion. Fifty-seven compounds in the aqueous extract of ZWD were identified by LC-MS. The results of PPI analysis showed that top hub genes involved epidermal growth factor receptor (EGFR), Signal Transducer and Activator of Transcription 3 (STAT3), Serine/Threonine Kinase 1 (AKT1), Vascular Endothelial Growth Factor A (VEGFA) and Fibroblast Growth Factor 2 (FGF2). Pathway enrichment analysis revealed the involvement of S1P1 receptor signaling and EGFR pathways. The results of molecular docking analysis showed that albiflorin has a high binding affinity to EGFR. Albiflorin could also exert protective effects in an HK-2 cell model of DKD, which may be related to the inhibition of the high glucose/high lipid-induced EGFR and Akt phosphorylation. Conclusion ZWD has been shown to be effective in ameliorating cell death in an experimental model of DKD. The beneficial effect of ZWD against DKD was associated with the interactions between the active ingredients and the hub genes, such as EGFR, STAT3, AKT1, and VEGF-A. Albiflorin may be one of the active components responsible for the nephroprotective effect in ZWD.