Capilliposide A attenuates diabetic nephropathy via modulation of NF-κB/TLR4 and apoptotic pathways

Abstract

This study aimed to identify therapeutic targets and signaling pathways of Capilliposide A (LC-A) for diabetic nephropathy (DN) through integrated network pharmacology and experimental validation. Using a DN mouse model induced by high-fat diet (HFD) and streptozotocin (STZ), we investigated the molecular mechanisms of LC-A. The PubChem database provided the two-dimensional structure of LC-A, with subsequent identification of LC-A/DN-associated targets through intersection analysis. Core targets were determined via protein–protein interaction (PPI) network construction, followed by gene ontology enrichment and pathway analyses. Molecular docking simulations evaluated LC-A's binding affinity to DN-related targets. C57BL/6 mice receiving HFD and STZ intraperitoneal injections were treated daily with LC-A or metformin (MET) via oral gavage for 8 weeks. Weekly monitoring included body weight and blood glucose measurements. Post-treatment assessments encompassed serum lipid profiles, renal function biomarkers, inflammatory cytokines, oxidative stress markers, and renal histopathology. Western blotting, immunohistochemistry, and immunofluorescence were performed to analyze inflammatory pathway proteins and apoptosis-related factors. Network pharmacology identified TLR4, NF-κB1, STAT3, EGFR, mTOR, and MAPK as core targets involved in inflammation, oxidative stress, and apoptosis regulation. Pathway enrichment analysis revealed critical inflammatory pathways including IL-17, TNF, and Th17 cell differentiation. Molecular docking confirmed stable binding of LC-A to TLR4, NF-κB1, Bax, and Bcl-2. In vivo experiments demonstrated that LC-A significantly reduced renal injury markers (KI, SCR, BUN), lipid profiles (TG, TC), and oxidative stress (MDA), while enhancing antioxidant enzymes (SOD, GPX, CAT) in DN mice (P < 0.05). LC-A effectively suppressed serum inflammatory cytokines (IL-6, TNF-α, IL-1β, MCP-1, iNOS) through NF-κB pathway modulation and apoptosis regulation (P < 0.05). Histopathological analysis revealed attenuated renal cortical vacuolization, tubular swelling, glomerular mesangial expansion, sclerosis, and inflammatory infiltration. These findings suggest LC-A as a promising natural nephroprotective agent for DN prevention and treatment.