RESUMEN
BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, posing a significant global health concern due to its increasing prevalence. Insulin resistance (IR) plays a major role in the development of T2DM and is often linked to factors such as obesity, physical inactivity, and a sedentary lifestyle. Recently, there has been growing interest in exploring the potential of natural products for improving insulin sensitivity and glucose metabolism. Among these, Cynomorium songaricum Rupr., an edible parasitic plant, has shown promising antidiabetic effects. However, research on its beneficial effects on IR is still nascent. Therefore, this study aims to investigate the application of a Cynomorium songaricum flavonoid-enriched fraction (CSF) in the treatment of IR in T2DM, along with elucidating the chemical and biochemical mechanisms involved. METHOD: First, UHPLC/ESI-LTQ-Orbitrap-MS was utilized to perform a chemical profiling of CSF. Subsequently, glycogen synthesis, gluconeogenesis and glucose consumption assays were conducted on HepG2 cells with a high glucose high insulin-induced IR model to illustrate the favorable impacts of CSF on IR. Then, an innovative network pharmacology analysis was executed to predict the potential chemical components and hub genes contributing to CSF's protective effect against IR. To further elucidate molecular interactions, molecular docking studies were performed, focusing on the binding interactions between active constituents of CSF and crucial targets. Additionally, an RNA-sequencing assay was employed to uncover the underlying biochemical signaling pathway responsible for CSF's beneficial effects. To validate these findings, western blot and qPCR assays were employed to verify the pathways related to IR and the potential signaling cascades leading to the amelioration of IR. RESULTS: The UHPLC/ESI-LTQ-Orbitrap-MS analysis successfully identified a total of thirty-six flavonoids derived from CSF. Moreover, CSF was shown to significantly improve glycogen synthesis and glucose consumption as well as inhibit gluconeogenesis in HepG2 cells of IR. An innovative network pharmacology analysis unveiled key hub genes-AKT1 and PI3K-integral to metabolic syndrome-related signaling pathways, which contributed to the favorable impact of CSF against IR. Noteworthy active ingredients including quercetin, ellagic acid and naringenin were identified as potential contributors to these effects. The results of western blot and qPCR assays provided compelling evidence that CSF improved insulin sensitivity by modulating the PI3K-Akt signaling pathway. Subsequent RNA-sequencing analysis, in tandem with western blot assays, delved deeper into the potential mechanisms underlying CSF's advantageous effects against IR, potentially associated with the enhancement of endoplasmic reticulum (ER) proteostasis. CONCLUSION: CSF exhibited a remarkable ability to enhance insulin sensitivity in the IR model of HepG2 cells. This was evident through enhancements in glycogen synthesis and glucose consumption, along with its inhibitory impact on gluconeogenesis. Furthermore, CSF demonstrated an improvement in the insulin-mediated PI3K-Akt signaling pathway. The potential active constituents were identified as quercetin, ellagic acid and naringenin. The underlying biochemical mechanisms responsible for CSF's beneficial effects against IR were closely linked to its capacity to mitigate ER stress, thereby offering a comprehensive understanding of its protective action.
RESUMEN
BACKGROUND: Diabetic kidney disease (DKD) is one of the major chronic microvascular complications of diabetes and the main cause of end-stage renal failure. Zhenwu Decoction (ZWD), an ancient classic herbal formula in Chinese medicine, has been clinically used for the treatment of kidney disease in China for many years. However, there is currently limited research investigating the application of ZWD in the treatment of DKD and the underlying chemical and biochemical mechanisms involved. Therefore, in the present study, we aimed to identify active components in ZWD and unravel the possible mechanism(s) of action for ZWD in treating DKD. METHODS: The protective effect of ZWD against DKD was evaluated utilizing an in vitro model of diabetic renal proximal tubulopathy. The major chemical components from ZWD were identified by LC-MS/MS. Drug targets were predicted by submitting the SMILES (Simplified Molecular Input Line Entry System) of the compounds to SEA (Similarity Ensemble Approach) search server and SwissTargetPrediction. The differentially expressed genes (DEGs) of the disease were collected and integrated from GeneCards. The constructions of "Compounds-potential targets interaction" (CTI) network and Protein-Protein Interaction (PPI) network, as well as topology analysis were conducted by Cytoscape. Gene Ontology (GO) enrichment and Metacore pathway enrichment analysis were also performed. Lastly, molecular docking and experimental studies were adopted to validate the core target and identify an active component(s) of ZWD. RESULTS: We demonstrated that the ZWD extract could significantly rescue the palmitic acid (PA) and high glucose-induced apoptotic cell death in HK-2 cells, and the cytoprotection was accompanied by decreases in the extent of reactive oxygen species (ROS) production, mitochondrial membrane depolarization and ATP depletion. Fifty-seven compounds in the aqueous extract of ZWD were identified by LC-MS. The results of PPI analysis showed that top hub genes involved epidermal growth factor receptor (EGFR), Signal Transducer and Activator of Transcription 3 (STAT3), Serine/Threonine Kinase 1 (AKT1), Vascular Endothelial Growth Factor A (VEGFA) and Fibroblast Growth Factor 2 (FGF2). Pathway enrichment analysis revealed the involvement of S1P1 receptor signaling and EGFR pathways. The results of molecular docking analysis showed that albiflorin has a high binding affinity to EGFR. Albiflorin could also exert protective effects in an HK-2 cell model of DKD, which may be related to the inhibition of the high glucose/high lipid-induced EGFR and Akt phosphorylation. CONCLUSION: ZWD has been shown to be effective in ameliorating cell death in an experimental model of DKD. The beneficial effect of ZWD against DKD was associated with the interactions between the active ingredients and the hub genes, such as EGFR, STAT3, AKT1, and VEGF-A. Albiflorin may be one of the active components responsible for the nephroprotective effect in ZWD.