The therapeutic mechanism of PuRenDan for the treatment of diabetic nephropathy: Network pharmacology and experimental verification

Schisandrin A Attenuates Diabetic Nephropathy via EGFR/AKT/GSK3β Signaling Pathway Based on Network Pharmacology and Experimental Validation

Diabetic nephropathy (DN) is one of the common complications of diabetes and the main cause of end-stage renal disease (ESRD) in clinical practice. Schisandrin A (Sch A) has multiple pharmacological activities, including inhibiting fibrosis, reducing apoptosis and oxidative stress, and regulating immunity, but its pharmacological mechanism for the treatment of DN is still unclear. In vivo, streptozotocin (STZ) and a high-fat diet were used to induce type 2 diabetic rats, and Sch A was administered for 4 weeks. At the same time, protein-protein interaction (PPI) networks were established to analyze the overlapping genes of DN and Sch A. Subsequently, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were performed to determine the hub pathway. In addition, molecular docking was used to preliminarily verify the affinity of hub proteins and Sch A. Further, H&E staining, Sirius red staining, immunohistochemistry, immunofluorescence, and western blot analysis were used to detect the location and expression of related proteins in DN. This study revealed the multi-target and multi-pathway characteristics of Sch A in the treatment of DN. First, Sch A could effectively improve glucose tolerance, reduce urine microprotein and urine creatinine levels, and alleviate renal pathological damage in DN rats. Second, EGFR was the hub gene screened in overlapping genes (43) of Sch A (100) and DN (2524). Finally, it was revealed that Sch A could inhibit the protein expression levels of EGFR and PTRF and reduced the expression of apoptosis-related proteins, and this effect was related to the modulation of the AKT/GSK-3β signaling pathway. In summary, Sch A has a protective effect in DN rats, EGFR may be a potential therapeutic target, throughout modulating AKT/GSK-3β pathway.

PuRenDan alleviates type 2 diabetes mellitus symptoms by modulating the gut microbiota and its metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

PuRenDan (PRD) is a traditional Chinese medicine formula comprising five herbs that have been traditionally used to treat type 2 diabetes mellitus (T2DM). While PRD has been shown to be effective in treating T2DM in clinical and animal studies, the mechanisms by which it works on the gut microbiome and metabolites related to T2DM are not well understood.

AIM OF THE STUDY

The objective of this study was to partially elucidate the mechanism of PRD in treating T2DM through analyses of the gut microbiota metagenome and metabolome.

MATERIALS AND METHODS

Sprague-Dawley rats were fed high-fat diets (HFDs) and injected with low-dose streptozotocin (STZ) to replicate T2DM models. Then the therapeutic effects of PRD were evaluated by measuring clinical markers such as blood glucose, insulin resistance (IR), lipid metabolism biomarkers (total cholesterol, low-density lipoprotein, non-esterified fatty acids, and triglycerides), and inflammatory factors (tumor necrosis factor alpha, interleukin-6 [IL-6], interferon gamma, and IL-1β). Colon contents were collected, and metagenomics, combined with ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry metabolic profiling, was performed to evaluate the effects of T2DM and PRD on gut microbiota and its metabolites in rats. Spearman analysis was used to calculate the correlation coefficient among different microbiota, clinical indices, and metabolites.

RESULTS

PRD exhibited significant improvement in blood glucose and IR, and reduced serum levels of lipid metabolism biomarkers and inflammatory factors. Moreover, the diversity and abundance of gut microbiota undergo significant changes in rats with T2DM that PRD was able to reverse. The gut microbiota associated with T2DM including Rickettsiaceae bacterium 4572_127, Psychrobacter pasteurii, Parabacteroides sp. CAG409, and Paludibacter propionicigenes were identified. The gut microbiota most closely related to PRD were Prevotella sp. 10(H), Parabacteroides sp. SN4, Flavobacteriales bacterium, Bacteroides massiliensis, Alistipes indistinctus, and Ruminococcus flavefaciens. Additionally, PRD regulated the levels of gut microbiota metabolites including pantothenic acid, 1-Methylhistamine, and 1-Methylhistidine; these affected metabolites were involved in pantothenate and coenzyme A biosynthesis, histidine metabolism, and secondary bile acid biosynthesis. Correlation analysis illustrated a close relationship among gut microbiota, its metabolites, and T2DM-related indexes.

CONCLUSION

Our study provides insights into the gut microbiota and its metabolites of PRD therapy for T2DM. It clarifies the role of gut microbiota and the metabolites in the pathogenesis of T2DM, highlighting the potential of PRD for the treatment of this disease.

Exploring the molecular mechanism of berberine for treating diabetic nephropathy based on network pharmacology

BACKGROUND AND PURPOSE

Diabetic nephropathy (DN) is a prevalent complication of diabetes mellitus characterized by hyperglycemia, hyperlipidemia, albuminuria and edema. Increasing evidence indicated that berberine (BBR) could alleviate the occurrence and development of DN. However, the molecular mechanism underlying the beneficial effects of BBR in the treatment of DN remains unclear.

METHODS

The online public databases were chosen to screen the relevant targets of BBR and DN and the screened overlapped targets were analyzed by GO enrichment analysis, KEGG enrichment analysis and protein-protein interaction network analysis. The interaction between BBR and the key proteinwas verified by molecular docking and cellularthermalshiftassay. Additionally, the expression of key proteins and related indicators of DN were verified by immunofluorescence and western blot in vitro and in vivo.

RESULTS

We successfully identified 92 overlapped targets of BBR and DN based on network pharmacology. Notably, VEGFR2 was identified to be the main target of BBR. Meanwhile, we found that BBR exhibited a high binding affinity to VEGFR2 protein, as confirmed by molecular docking and CETSA. This binding led to interfering with the PI3K/AKT/mTOR signaling pathway. In addition, we found that BBR could inhibit the abnormal proliferation of mesangial cells and reduce the expression of downstream pathway protein in vitro and in vivo. Finally, BBR was found to effectively lower the level of blood glucose and improve kidney function in mice, highlighting its potential as a therapeutic agent for the treatment of DN.

CONCLUSION

Berberine interfered the PI3K/AKT/mTOR signaling pathway via targeting VEGFR2 protein, further led to the inhibition of abnormal proliferation of mesangial cells and ultimately resulted in improved renal function.

Network pharmacology analysis combined with experimental validation to explore the therapeutic mechanism of Schisandra Chinensis Mixture on diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic nephropathy (DN) is one of the most common and serious microvascular complications of Diabetes mellitus (DM). The inflammatory response plays a critical role in DN. Schisandra Chinensis Mixture (SM) has shown promising clinical efficacy in the treatment of DN while the pharmacological mechanisms are still unclear.

AIM OF THE STUDY

In this study, a network pharmacology approach and bioinformatic analysis were adopted to predict the pharmacological mechanisms of SM in DN therapy. Based on the predicted results, molecular docking and in vivo experiments were used for verification.

MATERIALS AND METHODS

In this study, the candidate bioactive ingredients of SM were obtained via Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and supplementing according to the literature. SM putative targets and the verified targets were acquired from TCMSP and SiwssTartgetPrediction Database. DN-related target genes were collected from GeneCards, OMIM, DisGeNET databases, and microarray data analysis. Biological function and pathway analysis were performed to further explore the pharmacological mechanisms of SM in DN therapy. The protein-protein interaction (PPI) network was established to screen the hub gene. The Receiver Operating Characteristic (ROC) analysis and the molecular docking simulations were performed to validate the potential target-drug interactions. The fingerprint spectrum of multi-components of the SM was characterized by UPLC-MS/MS. The signaling pathways associated with inflammation and hub genes were partially validated in SD rats.

RESULTS

A total of 36 bioactive ingredients were contained, and 666 component-related targets were screened from SM, of which 50 intersected with DN targets and were considered potential therapeutic targets. GO analyses revealed that the 50 intersection targets were mainly enriched in the inflammatory response, positive regulation of angiogenesis, and positive regulation of phosphatidylinositol 3-kinase(PI3K) signaling. KEGG analyses indicated that the PI3K-Akt signaling pathway was considered as the most important pathway for SM antagonism to the occurrence and development of DN, with the highest target count enrichment. PPI network results showed that the top 15 protein targets in degree value, VEGFA, JAK2, CSF1R, NOS3, CCR2, CCR5, TLR7, FYN, BTK, LCK, PLAT, NOS2, TEK, MMP1 and MCL1, were identified as hub genes. The results of ROC analysis showed that VEGFA and NOS3 were valuable in the diagnosis of DN. The molecular docking confirmed that the core bioactive ingredients had well-binding affinity for VEGFA and NOS3. The in vivo experiments confirmed that SM significantly inhibited the over-release of inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor receptor (TNF)-α in DN rats, while regulating the PI3K-AKT and VEGFA-NOS3 signaling pathways.

CONCLUSION

This study revealed the multi-component, multi-target and multi-pathway characteristics of SM therapeutic DN. SM inhibited the inflammatory response and improved renal pathological damage in DN rats, which was related to the regulation of the PI3K-Akt and VEGFA-NOS3 signaling pathways.