OBJECTIVE: To investigate the effect of moxibustion on central insulin resistance related proteins of the rats suffering from diabetic cognitive decline, and analyze the underlying mechanism of moxibustion for cognition improvement. METHODS: Using the intraperitoneal injection of STZ combined with a high-fat diet, the rat model of diabetic cognitive decline were prepared. Twenty successfully-modeled rats were assigned randomly into a model group and a moxibustion group, 10 rats in each one. Besides, a blank group was set up with 10 rats collected. In the moxibustion group, suspending moxibustion was applied to "Baihui" (GV20), "Shenting" (GV24) and "Dazhui" (GV14) at the same time, 20 min in each intervention, once a day, and 6 interventions were delivered weekly and the duration of treatment was consecutive 4 weeks. The random blood glucose was measured using glucometer, and the learning-memory ability was detected by water maze test. HE staining was used to observe the morphology of neurons in the hippocampal tissue, real-time PCR assay was to detect mRNA expression of insulin receptor substrate 1 (IRS1), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) in the hippocampal tissue. The Western blot method was employed to detect the protein expression of IRS1, PI3K, AKT, phosphorylated IRS1 (p-IRS1), phosphorylated PI3K (p-PI3K) and phosphorylated AKT (p-AKT) in the hippocampal tissue, and the ratio of p-IRS1/IRS1, p-PI3K/PI3K and p-AKT/AKT was calculated separately. The immunofluorescence intensity of p-IRS1, p-PI3K, and p-AKT was measured using immunofluorescence. RESULTS: Compared with the blank group, the rats of the model group exhibited higher random blood glucose (P<0.001), longer escape latency (P<0.001), severe pathological damage in the hippocampus, lower mRNA expression of IRS1, PI3K, and AKT (P<0.001), reduced ratio of p-IRS1/IRS1, p-PI3K/PI3K and p-AKT/AKT (P<0.001), and declined immunofluorescence intensity of p-IRS1, p-PI3K, and p-AKT in the hippocampal tissue (P<0.001). In comparison with the model group, for the rats of the moxibustion group, the random blood glucose decreased (P<0.05), the escape latency was shortened (P<0.01), the hippocampal pathological damage was attenuated, the mRNA expression of IRS1, PI3K and AKT increased (P<0.01), the ratio of p-IRS1/IRS1, p-PI3K/PI3K and p-AKT/AKT was elevated (P<0.01, P<0.05), and the immunofluorescence intensity of p-IRS1, p-PI3K, and p-AKT in the hippocampal tissue was strengthened (P<0.01, P<0.05). CONCLUSION In diabetic rats experiencing cognitive decline, moxibustion can enhance the learning-memory ability, which may be attributed to modulating the protein expression of IRS1, PI3K, and AKT, and their phosphorylation, activating insulin signal transduction, and reducing central insulin resistance.
Animals ; Moxibustion ; Insulin Resistance ; Rats ; Male ; Insulin Receptor Substrate Proteins/genetics* ; Rats, Sprague-Dawley ; Humans ; Proto-Oncogene Proteins c-akt/genetics* ; Cognitive Dysfunction/genetics* ; Diabetes Mellitus, Experimental/therapy* ; Hippocampus/metabolism* ; Acupuncture Points ; Phosphatidylinositol 3-Kinases/genetics*

BACKGROUND: Epoxyeicosatrienoic acids (EETs), which are metabolites of arachidonic acid catalyzed by cytochrome P450 epoxygenase, are degraded into inactive dihydroxyeicosatrienoic acids by soluble epoxide hydrolase (sEH). Many studies have revealed that sEH gene deletion exerts protective effects against diabetes. Vascular calcification is a common complication of diabetes, but the potential effects of sEH on diabetic vascular calcification are still unknown. METHODS: The level of aortic calcification in wild-type and Ephx2-/- C57BL/6 diabetic mice induced with streptozotocin was evaluated by measuring the aortic calcium content through alizarin red staining, immunohistochemistry staining, and immunofluorescence staining. Mouse vascular smooth muscle cell lines (MOVAS cells) treated with β-glycerol phosphate (0.01 mol/L) plus advanced glycation end products (50 mg/L) were used to investigate the effects of sEH inhibitors or sEH knockdown and EETs on the calcification of vascular smooth muscle cells, which was detected by Western blotting, alizarin red staining, and Von Kossa staining. RESULTS: sEH gene deletion significantly inhibited diabetic vascular calcification by increasing levels of EETs in the aortas of mice. EETs (especially 11,12-EET and 14,15-EET) efficiently prevented the osteogenic transdifferentiation of MOVAS cells by decreasing nidogen-2 (NID2) expression. Interestingly, suppressing sEH activity by small interfering ribonucleic acid or specific inhibitors did not block osteogenic transdifferentiation of MOVAS cells induced by β-glycerol phosphate and advanced glycation end products. NID2 overexpression significantly abolished the inhibitory effect of sEH gene deletion on diabetic vascular calcification. Moreover, NID2 overexpression mediated by adeno-associated virus 9 vectors markedly increased insulin-like growth factor 2 (IGF2) and phospho-ERK1/2 expression in MOVAS cells. Overall, sEH gene knockout inhibited diabetic vascular calcification by decreasing aortic NID2 expression and, then, inactivating the downstream IGF2-ERK1/2 signaling pathway. CONCLUSIONS sEH gene deletion markedly inhibited diabetic vascular calcification through repressed osteogenic transdifferentiation of vascular smooth muscle cells mediated by increased aortic EET levels, which was associated with decreased NID2 expression and inactivation of the downstream IGF2-ERK1/2 signaling pathway.
Animals ; Mice ; Vascular Calcification/metabolism* ; Mice, Inbred C57BL ; Epoxide Hydrolases/metabolism* ; Diabetes Mellitus, Experimental/genetics* ; Male ; Gene Deletion ; MAP Kinase Signaling System/genetics* ; Cell Line ; Immunohistochemistry ; Muscle, Smooth, Vascular/metabolism* ; Signal Transduction/genetics* ; Mice, Knockout

Ultra performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry/mass spectrometry(UPLC-Q-TOF-MS/MS), network pharmacology, and animal experiments were integrated o explore the blood glucose-lowering effects and mechanisms of Poria aqueous extract. Firstly, the active components of Poria aqueous extract were identified by UPLC-Q-TOF-MS/MS. Subsequently, network pharmacology was employed to predict the blood glucose-lowering components and mechanisms of Poria aqueous extract. Finally, a rat model of diabetes mellitus, 16S rDNA sequencing, and Western blot were employed to investigate the blood glucose-lowering effect and mechanism of Poria aqueous extract. A total of 39 triterpenoids were identified in the Poria aqueous extract, among them, 25-hydroxypachymic acid, 25α-hydroxytumulosic acid, 16α-hydroxytrametenolic acid, polyporenic acid C, and tumulosic acid may be the main active ingredients for treating diabetes. The Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis revealed that Poria might exert its therapeutic effects through multiple pathways such as NOD-like receptor signaling pathway, nuclear factor-kappa B(NF-κB) signaling pathway, and tumor necrosis factor(TNF) signaling pathway. The results of animal experiments demonstrated that Poria aqueous extract significantly reduced the levels of blood glucose and lipids and regulated the intestinal flora in diabetic rats. The main affected taxa included g＿Escherichia-Shigella, g＿Corynebacterium, g＿Prevotella＿9, g＿Prevotellaceae＿UCG-001, and g＿Bacteroidota＿unclassified. In addition, Poria aqueous extract lowered the levels of D-lactic acid and lipopolysaccharide, alleviated colonic mucosal damage, significantly down-regulated the protein levels of NOD-like receptor pyrin domain-containing protein 3(NLRP3), NF-κB, and TNF-α, and significantly up-regulated the protein levels of zonula occludens 1 and occludin in diabetic rates. Poria aqueous extract may play a role in treating diabetes mellitus by repairing the intestinal flora disturbance, protecting the intestinal barrier function, and inhibiting the NF-κB/NLRP3 signaling pathway. The results provide a scientific basis for clinical application and expansion of indications of Poria.
Animals ; Rats ; Network Pharmacology ; Tandem Mass Spectrometry ; Male ; Drugs, Chinese Herbal/pharmacology* ; Chromatography, High Pressure Liquid ; Blood Glucose/drug effects* ; Rats, Sprague-Dawley ; Hypoglycemic Agents/administration & dosage* ; Poria/chemistry* ; Diabetes Mellitus, Experimental/metabolism* ; NF-kappa B/genetics* ; Gastrointestinal Microbiome/drug effects* ; Humans

OBJECTIVES: Spinal cord ischemia-reperfusion injury (SCIRI) remains a major challenge in the field of organ protection due to the lack of effective prevention and therapeutic strategies. Hyperglycemia, a common perioperative condition, contributes to neurological injury via multiple mechanisms. However, its role and underlying mechanism in SCIRI are still unclear. This study aims to investigate the involvement of the precursor of brain-derived neurotrophic factor (proBDNF) in hyperglycemia-induced SCIRI in mice. METHODS: Eight-week-old male C57BL/6 mice were randomly assigned to a control group (Vehicle) or a diabetes mellitus (DM) group. The DM group was established using intraperitoneal injection of streptozotocin (STZ) combined with 10% sucrose water. The Vehicle group received an equal volume of 50 mmol/L sodium citrate buffer (pH 4.5). Fasting blood-glucose levels ≥11.1 mmol/L were considered successful DM modeling. Both Vehicle and DM groups underwent SCIRI modeling via descending aortic clamping, while the Sham group underwent a sham procedure without aortic occlusion. Lower limb motor function was assessed using the Basso Mouse Scale (BMS) and its subscale (sub-BMS). Locomotor activity was evaluated using an open field test. Immunohistochemistry was performed to detect changes in neuronal nuclear protein (NeuN) and proBDNF expression in spinal cord tissues. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to measure mRNA expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). To explore the effect of proBDNF inhibition, diabetic mice were divided into groups: A DM+SCIRI+monoclonal anti-proBDNF antibody (McAb-proB) group received an intraperitoneal injection of 100 μg of McAb-proB 30 minutes before SCIRI modeling, and a DM+SCIRI+Vehicle group received an equal amount of isotype immunoglobulin G. BMS and sub-BMS scores were recorded, and the gene expression of inflammatory cytokines mentioned above were evaluated. RESULTS: Compared with the Vehicle+SCIRI group, the DM+SCIRI group showed significantly reduced BMS and sub-BMS scores, decreased NeuN expression, shorter total movement distance, slower locomotion, increased proBDNF expression, and elevated IL-1β, IL-6, and TNF-α mRNA levels (all P<0.05 or P<0.01). Compared with the DM+SCIRI+Vehicle group, the DM+SCIRI+McAb-proB group exhibited significantly improved BMS and sub-BMS scores and decreased mRNA expression of IL-1β, IL-6, and TNF-α (all P<0.05 or P<0.01). CONCLUSIONS Hyperglycemia exacerbates neural injury and inflammatory response in SCIRI through upregulation of proBDNF expression, delaying motor functional recovery. Antagonizing proBDNF expression can alleviate neurological damage and promote functional recovery in diabetic mice after SCIRI.
Animals ; Male ; Hyperglycemia/metabolism* ; Brain-Derived Neurotrophic Factor/genetics* ; Mice, Inbred C57BL ; Reperfusion Injury/metabolism* ; Mice ; Diabetes Mellitus, Experimental/metabolism* ; Inflammation/metabolism* ; Disease Models, Animal ; Spinal Cord/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Protein Precursors/genetics* ; Spinal Cord Ischemia/metabolism* ; Interleukin-6/metabolism* ; Interleukin-1beta/metabolism*

This study investigated the effect of Lianmei Qiwu Decoction(LMQWD) on the improvement of cardiac autonomic nerve remodeling in the diabetic rat model induced by the high-fat diet and explored the underlying mechanism of LMQWD through the AMP-activated protein kinase(AMPK)/tropomyosin receptor kinase A(TrkA)/transient receptor potential melastatin 7(TRPM7) signaling pathway. The diabetic rats were randomly divided into a model group, an LMQWD group, an AMPK agonist group, an unloaded TRPM7 adenovirus group(TRPM7-N), an overexpressed TRPM7 adenovirus group(TRPM7), an LMQWD + unloaded TRPM7 adenovirus group(LMQWD+TRPM7-N), an LMQWD + overexpressed TRPM7 adenovirus group(LMQWD+TRPM7), and a TRPM7 channel inhibitor group(TRPM7 inhibitor). After four weeks of treatment, programmed electrical stimulation(PES) was employed to detect the arrhythmia susceptibility of rats. The myocardial cell structure and myocardial tissue fibrosis of myocardial and ganglion samples in diabetic rats were observed by hematoxylin-eosin(HE) staining and Masson staining. The immunohistochemistry, immunofluorescence, real-time quantitative polymerase chain reaction(RT-PCR), and Western blot were adopted to detect the distribution and expression of TRPM7, tyrosine hydroxylase(TH), choline acetyltransferase(ChAT), growth associated protein-43(GAP-43), nerve growth factor(NGF), p-AMPK/AMPK, and other genes and related neural markers. The results showed that LMQWD could significantly reduce the arrhythmia susceptibility and the degree of fibrosis in myocardial tissues, decrease the levels of TH, ChAT, and GAP-43 in the myocardium and ganglion, increase NGF, inhibit the expression of TRPM7, and up-regulate p-AMPK/AMPK and p-TrkA/TrkA levels. This study indicated that LMQWD could attenuate cardiac autonomic nerve remodeling in the diabetic state, and its mechanism was associated with the activation of AMPK, further phosphorylation of TrkA, and inhibition of TRPM7 expression.
Rats ; Animals ; AMP-Activated Protein Kinases/metabolism* ; Nerve Growth Factor/metabolism* ; Diabetes Mellitus, Experimental/drug therapy* ; TRPM Cation Channels/metabolism* ; GAP-43 Protein/metabolism* ; Signal Transduction ; Diabetic Neuropathies/genetics* ; Fibrosis

This study investigated the mechanism of Gegen Qinlian Decoction(GQD) in improving glucose metabolism in vitro and in vivo by alleviating endoplasmic reticulum stress(ERS). Molecular docking was used to predict the binding affinity between the main effective plasma components of GQD and ERS-related targets. Liver tissue samples were obtained from normal rats, high-fat-induced diabetic rats, rats treated with metformin, and rats treated with GQD. RNA and protein were extracted. qPCR was used to measure the mRNA expression of ERS marker glucose-regulated protein 78(GRP78), and unfolded protein response(UPR) genes inositol requiring enzyme 1(Ire1), activating transcription factor 6(Atf6), Atf4, C/EBP-homologous protein(Chop), and caspase-12. Western blot was used to detect the protein expression of GRP78, IRE1, protein kinase R-like ER kinase(PERK), ATF6, X-box binding protein 1(XBP1), ATF4, CHOP, caspase-12, caspase-9, and caspase-3. The calcium ion content in liver tissues was determined by the colorimetric assay. The ERS-HepG2 cell model was established in vitro by inducing with tunicamycin for 6 hours, and 2.5%, 5%, and 10% GQD-containing serum were administered for 9 hours. The glucose oxidase method was used to measure extracellular glucose levels, flow cytometry to detect cell apoptosis, glycogen staining to measure cellular glycogen content, and immunofluorescence to detect the expression of GRP78. The intracellular calcium ion content was measured by the colorimetric assay. Whereas Western blot was used to detect GRP78 and ERS-induced IRE1, PERK, ATF6, and eukaryotic translation initiation factor 2α(eIF2α) phosphorylation. Additionally, the phosphorylation levels of insulin receptor substrate 1(IRS1), phosphatidylinositol 3-kinase regulatory subunit p85(PI3Kp85), and protein kinase B(Akt), which were involved in the insulin signaling pathway, were also measured. In addition, the phosphorylation levels of c-Jun N-terminal kinases(JNKs), which were involved in both the ERS and insulin signaling pathways, were measured by Western blot. Molecular docking results showed that GRP78, IRE1, PERK, ATF4, and various compounds such as baicalein, berberine, daidzein, jateorhizine, liquiritin, palmatine, puerarin and wogonoside had strong binding affinities, indicating that GQD might interfere with ERS-induced UPR. In vivo results showed that GQD down-regulated the mRNA transcription of Ire1, Atf6, Atf4, Grp78, caspase-12, and Chop in diabetic rats, and down-regulated GRP78, IRE1, PERK, as well as ERS-induced apoptotic factors ATF4 and CHOP, caspase-12, caspase-9, and caspase-3, while up-regulating XBP1 to enhance adaptive UPR. In addition, GQD increased the calcium ion content in liver tissues, which facilitated correct protein folding. In vitro results showed that GQD increased glucose consumption in ERS-induced HepG2 cells without significantly affecting cell viability, increased liver glycogen synthesis, down-regulated ATF6 and p-eIF2α(Ser51), and down-regulated IRE1, PERK, and GRP78, as well as p-IRS1(Ser312) and p-JNKs(Thr183/Tyr185), while up-regulating p-PI3Kp85(Tyr607) and p-Akt(Ser473). These findings suggested that GQD alleviates excessive ERS in the liver, reduces insulin resistance, and improves hepatic glucose metabolism in vivo and in vitro.
Rats ; Animals ; Proto-Oncogene Proteins c-akt ; Endoplasmic Reticulum Chaperone BiP ; Caspase 3 ; Caspase 9 ; Diabetes Mellitus, Experimental ; Caspase 12 ; Calcium/pharmacology* ; Molecular Docking Simulation ; Endoplasmic Reticulum Stress ; Protein Serine-Threonine Kinases/genetics* ; Liver ; Apoptosis ; Insulin ; Glucose ; Glycogen/pharmacology* ; RNA, Messenger

Objective: To identify the differentially expressed circular RNA (circRNA) in the myocardium of diabetic cardiomyopathy (DCM) mice, and analyze their possible biological functions and related regulatory network. Methods: C57BL/6 mice, aged 8 weeks, and weighing were 21-27 g. Eight mice were selected as the control group and 15 mice were selected as the experimental group. The diabetic mice model was established by intraperitoneal injection of streptozotocin in the experimental group. One week after injection, the fasting blood glucose level of mice was measured, and 12 diabetic mice were included in the final experimental group. All mice were fed for 12 weeks under the same laboratory conditions. The cardiac structure and function were detected by echocardiography. Diabetic mice with the left ventricular ejection fraction less than 60% and the E/A less than 1.6 were selected as DCM group (n=3). Mice in DCM group and control group were then sacrificed under deep anesthesia. RNA was extracted from myocardial tissue. High-throughput RNA sequencing technology was used to sequence and identify the RNA in the myocardial tissue of DCM group and normal control group, and the difference was analyzed by DeSeq2. The analysis results were verified at the tissue level by RT-qPCR, and the differential circRNA were analyzed by GO and KEGG pathway analysis. The differentially expressed circRNA-microRNA(miRNA) interaction was predicted by the miRNA target gene prediction software. Results: A total of 63 differentially expressed circRNAs were found in the myocardium of DCM mice. The results of RT-qPCR showed that the tissue level expression of 8 differentially expressed circRNAs was consistent with the sequencing results, of which 7 were up-regulated and 1 was down-regulated. KEGG pathway analysis showed that the up-regulated circRNAs was mainly related to AMPK signal pathway and intercellular adhesion junction pathway, and the down-regulated circRNA was mainly related to cardiomyopathy. Go analysis showed that the up-regulated circRNA was mainly related to the binding process of ions, proteins, kinases and other factors in terms of molecular function, and was involved in regulating the intracellular structure, especially the composition of organelles in terms of cell components. The functional analysis of molecular function and cell components showed that the up-regulated circRNA were related to the cell component origin, recruitment and tissue, and thus participated in the regulation of cell biological process. The down regulated circRNA was related to catalytic activity in terms of molecular function, protein kinase binding process, transferase and calmodulin activity, and was closely related to the components of contractile fibers and the composition of myofibrils. These differentially expressed circRNAs were also related to biological processes such as lysine peptide modification, sarcomere composition, myofibril assembly, morphological development of myocardial tissue, myocardial hypertrophy and so on. Conclusions: In this study, we detected the novel differentially expressed circRNAs in the myocardium of DCM mice, and bioinformatics analysis confirmed that these circRNAs are related to oxidative stress, fibrosis and death of cardiomyocytes, and finally participate in the pathophysiological process of DCM.
Animals ; Diabetes Mellitus, Experimental ; Diabetic Cardiomyopathies/genetics* ; Gene Expression Profiling/methods* ; Mice ; Mice, Inbred C57BL ; MicroRNAs/genetics* ; Myocardium ; RNA, Circular ; Stroke Volume ; Ventricular Function, Left

OBJECTIVE: To explore the mechanisms of Dangua Recipe (DGR) in improving glycolipid metabolism based on transcriptomics. METHODS: Sprague-Dawley rats with normal glucose level were divided into 3 groups according to a random number table, including a conventional diet group (Group A), a DGR group (Group B, high-calorie diet + 20.5 g DGR), and a high-calorie fodder model group (Group C). After 12 weeks of intervention, the liver tissue of rats was taken. Gene sequence and transcriptional analysis were performed to identify the key genes related to glycolipid metabolism reflecting DGR efficacy, and then gene or protein validation of liver tissue were performed. Nicotinamide phosphoribosyl transferase (Nampt) and phosphoenolpyruvate carboxykinase (PEPCK) proteins in liver tissues were detected by enzyme linked immunosorbent assay, fatty acid synthase (FASN) protein was detected by Western blot, and fatty acid binding protein 5 (FABP5)-mRNA was detected by quantitative real-time polymerase chain reaction. Furthermore, the functional verification was performed on the diabetic model rats by Nampt blocker (GEN-617) injected in vivo. Hemoglobin A RESULTS: Totally, 257 differential-dominant genes of Group A vs. Group C and 392 differential-dominant genes of Group B vs. Group C were found. Moreover, 11 Gene Ontology molecular function terms and 7 Kyoto Encyclopedia of Genes and Genomes enrichment pathways owned by both Group A vs. Group C and Group C vs. Group B were confirmed. The liver tissue target validation showed that Nampt, FASN, PEPCK protein and FABP5-mRNA had the same changes consistent with transcriptome. The in vivo functional tests showed that GEN-617 increased body weight, HbA CONCLUSION Nampt activation was one of the mechanisms about DGR regulating glycolipid metabolism.
Animals ; Diabetes Mellitus, Experimental ; Drugs, Chinese Herbal ; Glycolipids ; Liver ; Metabolic Diseases ; Rats ; Rats, Sprague-Dawley ; Transcriptome/genetics*

This study investigated the protective effects of Moutan Cortex polysaccharides components(MCPC) on the renal tissues of diabetic nephropathy(DN) rats and explored their regulation effect on inflammatory response and oxidative stress. The DN rat model was induced by high-glucose and high-fat diet combined with streptozotocin(STZ), and then the rats were randomly divided into control group, model group, positive group and MCPC high(120 mg·kg~(-1)·d~(-1)), low(60 mg·kg~(-1)·d~(-1)) dose groups. After 12 weeks treatment, blood was taken from the orbit of the rats, and then they were sacrificed before the kidney tissues were collected. The serum and tissues were detected for related biochemical indicators and pathological changes of the kidney. Immunohistochemical methods were used to determine the expression of FN and ColⅣ in the kidney tissue of DN rats. Compared with the model group, blood glucose, serum creatinine, blood urea nitrogen and 24 h urine protein in the MCPC high-dose group were significantly reduced(P<0.01). The results of HE, PAS, Masson staining showed that glomerular basement membrane thickening, Bowman's capsule narrowing and inflammatory cell infiltration in DN rats were improved in the MCPC high-dose group; the activity of T-SOD and GSH-Px in serum significantly increased(P<0.001), and the expression level of FN significantly decreased(P<0.001). The high-dose MCPC treatment could effectively inhibit the abnormal expression of Col Ⅳ(P<0.001) and significantly reduce the levels of AGEs and RAGE in serum(P<0.001), the content of VCAM-1 and IL-1β in serum(P<0.001), and the levels of IL-1β mRNA in kidney tissue(P<0.001), but failed to effectively reduce VCAM-1 mRNA levels in kidney tissues. The high-dose MCPC could significantly improve pathological injury of renal tissue and related renal indicators in DN rats, and achieve renal protection in DN rats mainly by regulating oxidative stress and inflammatory factors.
Animals ; Diabetes Mellitus, Experimental/genetics* ; Diabetic Nephropathies/genetics* ; Drugs, Chinese Herbal ; Kidney ; Paeonia ; Polysaccharides/pharmacology* ; Rats

Ginsenoside Rg_1, one of the main active components of precious traditional Chinese medicine Ginseng Radix et Rhizoma, has the anti-oxidative stress, anti-inflammation, anti-aging, neuroprotection, and other pharmacological effects. Diabetic retinopathy(DR), the most common complication of diabetes, is also the main cause of impaired vision and blindness in the middle-aged and the elderly. The latest research shows that ginsenoside Rg_1 can protect patients against DR, but the protection and the mechanism are rarely studied. This study mainly explored the protective effect of ginsenoside Rg_1 against DR in type 2 diabetic mice and the mechanism. High fat diet(HFD) and streptozotocin(STZ) were used to induce type 2 diabetes in mice, and hematoxylin-eosin(HE) staining was employed to observe pathological changes in the retina of mice. The immunohistochemistry was applied to study the localization and expression of nucleotide-binding oligomerization domain-like receptors 3(NLRP3) and vascular endothelial growth factor(VEGF) in retina, and Western blot was used to detect the expression of nuclear factor-kappa B(NF-κB), p-NF-κB, NLRP3, caspase-1, interleukin-1β(IL-1β), transient receptor potential channel protein 6(TRPC6), nuclear factor of activated T-cell 2(NFAT2), and VEGF in retina. The results showed that ginsenoside Rg_1 significantly alleviated the pathological injury of retina in type 2 diabetic mice. Immunohistochemistry results demonstrated that ginsenoside Rg_1 significantly decreased the expression of NLRP3 and VEGF in retinal ganglion cells, middle plexiform layer, and outer plexiform layer in type 2 diabetic mice. According to the Western blot results, ginsenoside Rg_1 significantly lowered the expression of p-NF-κB, NLRP3, caspase-1, IL-1β, TRPC6, NFAT2, and VEGF in retina of type 2 diabetic mice. These findings suggest that ginsenoside Rg_1 can significantly alleviate DR in type 2 diabetic mice, which may be related to inhibition of NLRP3 inflammasome and VEGF. This study provides experimental evidence for the clinical application of ginsenoside Rg_1 in the treatment of DR.
Aged ; Animals ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Type 2/genetics* ; Diabetic Retinopathy/genetics* ; Ginsenosides/pharmacology* ; Humans ; Inflammasomes/metabolism* ; Mice ; Middle Aged ; NF-kappa B/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Signal Transduction ; Vascular Endothelial Growth Factor A/genetics*