The purpose of this study was to investigate differences in the pharmacodynamic, pharmacokinetic, and kidney distribution between Ligustri Lucidi Fructus (LLF) and wine-steamed Ligustri Lucidi Fructus (WLL) extracts in diabetic nephropathy (DN) rats. The DN rats were induced by high-fat-sugar diet (HFSD)/streptozotocin (STZ) regimen. For pharmacodynamics, the DN rats were treated with LLF and WLL extracts to assess the anti-diabetic nephropathy effects. For pharmacokinetics and kidney distribution, the concentrations of drugs (hydroxytyrosol, salidroside, nuezhenidic acid, oleoside-11-methyl ester, specnuezhenide, 1‴-O-β-d-glucosylformoside, G13, and oleonuezhenide) were determined. Regarding the pharmacodynamics, LLF and WLL extracts decreased the levels of blood glucose, serum creatinine (SCr), blood urea nitrogen (BUN), and 24-h urinary protein (24-h Upro) in DN rats. Furthermore, LLF and WLL extracts increased the level of high-density lipoprotein cholesterol (HDL-C); decreased the levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C); and reduced levels of pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) in DN rats. The anti-diabetic nephropathy effect of the WLL extract was better than that of the LLF extract. Regarding the pharmacokinetic and kidney tissue distribution, there were obvious differences in the eight ingredients between LLF and WLL extracts in DN rats. LLF and WLL extracts had protective effects on DN rats, while the WLL extract was better than the LLF extract regarding anti-diabetic nephropathy effects. The pharmacokinetic parameters and kidney distribution showed that wine-steaming could affect the absorption and distribution of the eight ingredients. The results provided a reasonable basis for the study of the clinical application and processing mechanism of LLF.

Background: Diabetic retinopathy (DR) represents a major microvascular complication arising from diabetes mellitus, characterized by multifactorial pathogenesis encompassing genetic, metabolic, and microbial components. While Dihuang Yinzi (DHYZ), a traditional Chinese herbal formulation, exhibits therapeutic promise for DR management, the precise mechanistic underpinnings warrant further investigation. This research sought to elucidate critical target genes, metabolic compounds, and microbial species implicated in DHYZ's therapeutic action against DR. Methods: We constructed a murine DR model and procured biological specimens from 18 animals distributed across three experimental cohorts (control, disease model, and DHYZ-treated groups, n = 6 per group) for metabolomic profiling and microbiome characterization. Candidate genes emerged from overlapping DHYZ-associated targets with DR-linked genes. Through six computational algorithms within the cytoHubba plugin, we pinpointed pivotal target genes. Molecular docking studies examined binding affinity between essential target proteins and bioactive constituents. Metabolomic and microbiome datasets underwent differential expression analysis to enumerate candidate metabolites and microbial taxa, respectively. Finally, Spearman correlation-based integrative omics analysis distinguished critical metabolites and key microbial species. Results: We identified 110 candidate genes and five key target genes (STAT3, IL6, TNF, ESR1, and IL1B). Molecular docking analysis revealed strong binding interactions between ESR1 and six corresponding active compounds, with the highest binding affinity observed for naringenin. Additionally, metabolomic analysis identified 50 candidate metabolites, and microbiome analysis revealed 24 candidate microbes. Spearman correlation analysis further pinpointed 30 key metabolites and 18 key microbes. Conclusion: This study elucidates five key target genes, 30 key metabolites, and 18 key microbes through which DHYZ may exert its therapeutic effects in DR. These findings provide valuable insights and a foundational reference for understanding the multi-omics mechanism of DHYZ in the treatment of diabetic retinopathy.