Unraveling the mechanisms of Schisandra Chinensis Mixture against diabetic nephropathy by integrating serum pharmacochemistry, network pharmacology, transcriptomics, and metabolomics.

ETHNOPHARMACOLOGICAL RELEVANCE: Schisandra Chinensis Mixture (SM), a classic TCM formula derived from Bugan Decoction in Zhang Sanxi's Medical Essentials in Six Parts (1615 CE), has demonstrated efficacy in treating diabetic nephropathy (DN), though its underlying mechanisms await full elucidation.

AIM OF THE STUDY: To decipher the specific composition of SM and its synergistic mechanisms against DN, focusing on ferroptosis regulation, using an integrative multi-omics approach.

MATERIALS AND METHODS: The bioactive components absorbed into the bloodstream (serum pharmacochemistry) after SM administration were identified using UPLC-ESI-MS/MS. Network pharmacology was employed to predict the main therapeutic targets and biological pathways related to SM's anti-DN effects. Molecular docking and surface plasmon resonance (SPR) assays validated interactions between key SM components and core target proteins. A DN rat model was established using a high-sugar, high-fat diet combined with streptozotocin injection. The effectiveness of SM in safeguarding the kidneys was evaluated by the renal index, liver and kidney function, blood glucose and lipid levels, histological analysis, and ferroptosis-related indices in renal tissue. To clarify the mechanism of SM, a combined analysis of metabolomics and transcriptomics was conducted, revealing changes in glycerophospholipid metabolism and the inhibition of ferroptosis. Key findings from multi-omics, serum pharmacochemistry, and network pharmacology were further validated using RT-PCR, western blot, ELISA, immunofluorescence (IF), and immunohistochemistry (IHC).

RESULTS: 22 prototype compounds derived from SM were characterized using serum pharmacochemistry. Using network pharmacology, we identified 206 common targets of SM for DN treatment. Notably, protein-protein interaction and enrichment analyses highlighted mitochondrial energy restoration, atherosclerosis, lipid metabolism disorders, and ferroptosis as key mechanisms underlying the anti-DN effects of SM. According to molecular docking and SPR analyses, the principal components strongly bind to the core targets. Pharmacodynamic studies indicated that SM significantly enhanced liver and kidney function, improved lipid metabolism indices, and ameliorated pathological characteristics in DN. SM aided in restoring mitochondrial structure and function while also inhibiting oxidative stress and ferroptosis phenotypes. Integrated metabolomics and transcriptomics analyses revealed significant disruptions in the glycerophospholipid metabolism pathway in DN rats, which SM was able to rectify, thereby restoring the lipid metabolic balance impaired by DN. Further validation through RT-PCR, western blot, ELISA, IF, and IHC experiments confirmed SM's capacity to restore mitochondrial structure and function, reduce lipid peroxidation, and inhibit ferroptosis in DN by regulating key genes, enzymes and metabolites in the glycerophospholipid metabolism pathway.

CONCLUSIONS: This study provides initial insights into the mechanism through which SM may inhibit ferroptosis in DN, potentially involving glycerophospholipid reprogramming to support mitochondrial integrity. Our observations contribute to a broader understanding of relevant metabolic pathways and key genes associated with this process. The methodological framework applied here helps clarify the multi-compartmental suppression of lipid peroxidation by SM, laying a tentative foundation for future research on phytotherapeutic strategies targeting ferroptosis.