ETHNOPHARMACOLOGICAL RELEVANCE: Diabetic nephropathy (DN) is a common and severe complication of diabetes which could ultimately progress to end-stage renal disease. Zhijun Tangshen Decoction (ZJTSD), a traditional Chinese herbal formula, has shown clinically beneficial effects in the treatment of DN. However, the mechanisms of ZJTSD against DN remain unclear.
AIM OF THE STUDY: This study was aimed to evaluate the anti-DN effect of ZJTSD in rats and further investigate its potential mechanisms against DN.
METHODS: The streptozotocin (STZ)-induced DN model was established in SD rats. The protective effect of ZJTSD on the DN rats was assessed by biochemical markers, inflammatory cytokines, renal measurements, and histopathological analysis. The migrant components of ZJTSD in the rat kidneys, including both prototype compounds and metabolites, were identified utilizing UPLC-Q-TOF-MS. Besides, renal metabolomics was conducted to identify potential biomarkers and metabolic pathways, while transcriptomics of kidneys was used to uncover related signaling pathways. Network pharmacology analysis based on prototype compounds and metabolites of ZJTSD found in the kidneys was used to predict the action biological network. Finally, a comprehensive strategy involving metabolomics, transcriptomics, and network pharmacology was integrated to elucidate the underlying mechanisms of ZJTSD, and the key proteins involved in the mechanisms were validated by Western blotting assay.
RESULTS: The results of biochemical indexes and ELISA showed that ZJTSD could significantly improve blood glucose levels and renal function, inhibiting the inflammatory response and renal fibrosis in model rats. The pathological results suggested that ZJTSD could alleviate histological changes, renal injury, and interstitial fibrosis in DN rat kidney tissue. Renal metabolome indicated that amino acid metabolism and nucleotide metabolism may represent the primary pathways affected by ZJTSD treatment. Transcriptomic analysis was applied to identify differentially expressed genes among the control, model, and ZJTSD-H groups, resulting in the identification of 93 differentially expressed genes from the intersection of these groups. The functional enrichment analysis suggested that DEGs were mainly involved in biological processes, including cellular metabolism, immune regulation, and oxidative stress response. A total of 191 compounds were identified in the kidney, comprising 54 prototype compounds and 137 metabolites, with flavonoids identified as the predominant active constituents. Network pharmacology analysis indicated that ZJTSD targets key proteins, including EGFR, STAT3, HSP90AA1, AKT1, and SRC. Comprehensive integrative analysis revealed that there were nine pathways related to DN, including PI3K-Akt signaling pathway, Phospholipase D signaling pathway, Natural killer cell mediated cytotoxicity, MAPK signaling pathway, Fc γ R-mediated phagocytosis, Fc epsilon RI signaling pathway, Endocrine and other factor-regulated calcium reabsorption, Complement and coagulation cascades, and B cell receptor signaling pathway, reflecting that ZJTSD demonstrated therapeutic effects against diabetic nephropathy through a synergistic mechanism involving multi-components, multi-targets, and multi-pathways interactions.
CONCLUSION: In this study, ZJTSD was able to effectively regulate DN in vivo. By integrating multi-omics and network pharmacology, we explored its potential mechanisms against DN, thus providing a theoretical basis for ZJTSD in the clinical treatment of DN.
