ABSTRACT
ObjectiveTo investigate the effect of Jingui Shenqiwan on diabetic osteoporosis （DOP） in mice by regulating the advanced glycation end products （AGEs）/receptor activator of nuclear factor-κB ligand （RANKL）/nuclear factor-κB （NF-κB） signaling pathway based on the theory of "kidneys governing bones". MethodForty 6-week-old male and female skeletal-muscle-specific， dominant negative insulin-like growth factor-1 receptor （MKR） mice were selected and fed on a high-fat diet for eight weeks to establish the DOP model. The model mice were randomly divided into a model group， low- and high-dose Jingui Shenqiwan group （1.3， 2.6 g·kg-1）， and an alendronate sodium group （0.01 g·kg-1）， with 10 mice in each group. Additionally， 10 FVB/N mice of the same age were assigned to the normal group. The corresponding drugs were administered orally to each group once a day for four weeks. After the administration period， fasting blood glucose （FBG） measurement and oral glucose tolerance test （OGTT） were conducted. Kidney function and kidney index were measured. Renal tissue pathological changes were observed through hematoxylin-eosin （HE） and Masson staining. Immunohistochemistry was performed to assess the protein expression levels of AGEs， phosphorylated NF-κB （p-NF-κB）， and RANKL in renal tissues. Western blot analysis was conducted to measure the expression of proteins related to the AGEs/RANKL/NF-κB signaling pathway， osteoprotegerin （OPG）， and Runt-related transcription factor 2 （RUNX2） proteins in femoral bone tissues. ResultCompared with the normal group， mice in the model group exhibited significantly increased FBG （P<0.01）， trabecular bone degeneration， abnormal bone morphological parameters， significantly increased area under the curve （AUC） of OGTT （P<0.01）， enlarged kidney volume， significantly increased kidney function indicators and kidney index （P<0.01）， disrupted renal glomeruli and renal tubule structures， significantly increased expression of AGEs， RANKL， and p-NF-κB/NF-κB in renal tissues （P<0.05）， and significantly decreased expression of OPG and RUNX2 in femoral bone tissues （P<0.01）. Compared with the model group， mice in the Jingui Shenqiwan groups showed a significant decrease in OGTT AUC （P<0.01）. Histopathological analysis revealed alleviated structural lesions in renal glomeruli and renal tubules. Furthermore， the expression of AGEs， RANKL， and p-NF-κB/NF-κB in renal tissues was significantly reduced （P<0.05， P<0.01）， and the expression of RUNX2 and OPG in femoral bone tissues was significantly increased （P<0.05， P<0.01）. ConclusionJingui Shenqiwan can improve kidney function and downregulate the AGEs/RANKL/NF-κB signaling pathway to inhibit inflammatory reactions， thereby alleviating the symptoms of DOP in mice， demonstrating a therapeutic effect on DOP from the perspective of the kidney.
ABSTRACT
Advanced glycation end-products (AGEs) are the products of non-enzymatic reactions between free amino groups of macromolecules and reducing sugars. AGEs accumulation in bone tissues changes the activity and function of bone cells by binding to their surface receptors, causing abnormalities in the process of bone remodeling. AGEs accumulation can also change the original structure and mineral deposition of bone collagen, affect the micro-mechanical properties of bone tissues, and further reduce bone strength and toughness, increase the bone fracture risk, which will lead to bone diseases and do great harm to human health. This article summarized the causes of AGEs and their detection methods, and reviewed previous studies about the effects of AGEs accumulation on bone biomechanics at micro and macro levels, so as to provide references for the early diagnosis and treatment of bone diseases in clinic.
ABSTRACT
Objective:To study the effect of Huangqi Guizhi Wuwutang on receptor of advanced glycation end products(AGEs)/advanced glycation endproducts (RAGE)/nuclear transcription factor-kappa B p65 (NF-κB p65) signaling pathway in the diabetic peripheral neuropathy rats through an animal modeling experiment, and discuss the mechanism of Huangqi Guizhi Wuwutang in alleviating diabetic peripheral neuropathy. Method:Rat model of diabetic peripheral neuropathy was established by high-fat diet and intraperitoneal injection with streptozotocin (STZ). After successful modeling, Huangqi Guizhi Wuwutang intervention began in the fifth week. The patients in high-dose group (19.40 g∙kg-1∙d-1), middle-dose group (4.85 g∙kg-1∙d-1) and low-dose group (2.43 g∙kg-1∙d-1) were given by gavage continuously for 12 weeks. The western medicine control group was given 25 mg∙kg-1∙d-1 by gavage. After the experiment, serum interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). Real-time fluorescent quantitative polymerase chain reaction (Real-time PCR) was used to detect RAGE and NF-κB p65 mRNA expressions in sciatic nerve tissue. The expressions of RAGE, NF-κB and phosphorylation(p)-NF-κB p65 proteins in sciatic nerve tissues were detected by Western blot (WB). Result:Compared with the normal group, serum IL-1β and TNF-α protein levels, RAGE mRNA and NF-κB p65 mRNA levels, RAGE protein, NF-κB p65 protein and p-NF-κB p65 protein levels were significantly increased in the model group (P<0.01), the ratio of p-NF-κB p65 to NF-κB p65 was increased, and the phosphorylation of NF-κB p65 was enhanced (P<0.01). After the intervention of Huangqi Guizhi Wuwutang, compared with the model group, serum IL-1β and TNF-α protein levels, RAGE and NF-κB p65 mRNA levels, RAGE protein, NF-κB p65 protein and p-NF-κB p65 protein levels were all decreased (P<0.01), the ratio of p-NF-κB p65 to NF-κB p65 was decreased in high-dose group (P<0.01). The effect was obvious with the increase of dose of astragalus cassia twig. Conclusion:Huangqi Guizhi Wuwutang can alleviate diabetic peripheral neuropathy, and its mechanism may be related to blocking the expression of RAGE on tissue cell surface in AGEs/RAGE/NF-κB signaling pathway, inhibiting the activation of NF-κB and inducing TNF-α triggered oxidative stress and excessive inflammatory response, so as to avoid cell damage and dysfunction.
ABSTRACT
The long-term existence of hyperglycemia leads to the occurrence of metabolic memory effect， which is an important reason for the formation of diabetic macrovascular disease， so the early control of metabolic memory is the key to the prevention and treatment of diabetes and its complications. The excessive formation of advanced glycation end products （AGEs） is not only an important factor to cause metabolic memory， but also the core mechanism for diabetic macrovascular disease. It is believed in traditional Chinese medicine（TCM） that Fu-xie （incubative pathogen） is the key pathogenesis of the formation of diabetic vascular diseases， and it is necessary to adopt the principle of removing pathogenic factors and opening collaterals as early as possible to prevent and cure the disease. During the Spring and Autumn Period and the Warring States Period， the theory of Fu-xie was germinated， and got mature in the Ming and Qing dynasties after the continuous development. The so-called Fu-xie means that the pathogens are of a potential nature but not cause diseases immediately. The theory of Fu-xie first appeared in Huangdi Neijing， with an original meaning of epidemic febrile disease occurring after incubation， and then its meaning continues to expand， now referring to all potential pathogenic factors that would not immediately cause diseases. As the cause and pathogenesis of many diseases， the theory of Fu-xie is widely used in clinical practice to guide the treatment of diseases. In the body， the accumulation of AEGs can induce the subsequent cascade effect in the body， and finally promote the formation and development of diabetic macrovascular diseases. This is very similar to the process of inducing metabolic disorder and disease in TCM due to the accumulation of phlegm and silt. Therefore， under the guidance of Fu-xie theory， the mechanism of AEGs in blocking metabolic memory and preventing and treating diabetic macrovascular disease was analyzed in this paper. On the one hand， it will provide a scientific basis for the exploration of Fu-xie theory affecting the disease course of diabetic macrovascular disease by regulating the generation of AEGs. On the other hand， it can also provide the material change basis for the development of Fu-xie theory in the occurrence and development of diabetic macroangiopathy.
ABSTRACT
@#Firstly, three 3-arylcoumarins 4a- 4c were synthesized from p-aminophenylacetic acid and salicylaldehyde by Perkin condensation reaction and hydrochloric acid acidification; subsequent-amidation reaction of 4a- 4c with substituted benzoyl chlorides 6a- 6h furnished; ten 3-(4′-benzoyl amino-phenyl)coumarins 7a- 7j. The structures of all target compounds were fully characterised by NMR and ESI-MS. Those target compounds were screened for-glucosidase inhibitory and advanced glycation end products(AGEs)formation inhibitory activity. The results showed that compound 7f had good inhibitory activity against α-glucosidase(IC50=10. 84±0. 36 μmol/L); compound 7g possessed much more potent inhibitory activity against AGEs formation(IC50=5. 01±0. 55 μmol/L)than the positive control aminoguanidine hydrochloride(IC50=290. 31±7. 32 μmol/L). These results provided a theoretical basis for further research on antidiabetic drugs.
ABSTRACT
AIM To study the efficacy of different extractions of Huidouba,a Tibetan medicine to mice with type Ⅱ diabetic kidney disease (DKD).METHODS The type Ⅱ DKD mice models induced by the injection of streptozotocin (STZ) on base of high glucose and high fat diet subsequently treated with different extractions of Huidouba were studied to investigate the protective effects of Huidouba on renal injury.The mice were given high dose (200 mg/kg) and low dose (100 mg/kg) of Huidouba ethanol extract,Huidouba water extract and Huidouba polysaccharide respectively for 8 weeks.Their serum creatinine (SCr),blood urea nitrogen (BUN),urine protein (mg/24 h),glycosylated serum protein (Gsp) and advanced glycation end products (AGEs),their histological changes of renal pathology were detected and analyzed.Meanwhile their protein levels of fibronectin (FN),intercellular adhesion factor (ICAM-1) and transforming growth factor (TGF-β1) were identified by Western blot.RESULTS The different extractions of Huidouba,demonstrating a portfolio of capacity in decreasing levels of serum glucose and AGEs,inhibiting the expression of target protein,alleviating the glomerular basement membrane thickening,improving mesangial matrix,renal tubular and epithelial cells degeneration and other pathological conditions,improved the renal function of DKD mice.CONCLUSION The three extractions of Huidouba highlight the renal improvements in type Ⅱ DKD mice.
ABSTRACT
Background Industrial food processing induces protein glycation modifications and toxic advanced glycation end products (AGEs) which affect human health. Therefore, it is of interest to monitor AGEs in food processing. The present study was carried out to investigate the influence of lotus seedpod oligomeric procyanidin (LSOPC) concentrations, solution pH value and metal ions on AGE formation by heat treatment of lactose-lysine model solutions. Ne-(carboxymethyl) lysine (CML), as one of the common AGEs was also determined by HPLC-MS/MS in this experiment. Results The results showed that LSOPC can inhibit the formation of AGEs effectively at higher concentrations, lower temperature, and it can reverse the promotion function of metal ions because of its high inhibition activity. Also, LSOPC can inhibit CML formation in the Maillard reaction as well. Conclusion These results indicated that LSOPC could be used as functional food ingredients to inhibit AGE formation.
Subject(s)
Seeds/chemistry , Glycation End Products, Advanced/metabolism , Proanthocyanidins/metabolism , Temperature , Maillard Reaction , Chromatography, High Pressure Liquid , Lotus/chemistry , Hydrogen-Ion Concentration , Lactose/chemistry , Lysine/chemistry , Models, ChemicalABSTRACT
Qifu-Yin (QFY), a widely used formula of traditional Chinese medicine (TCM) derived from "Jingyue Quanshu", is one of the most commonly used TCM prescriptions for the clinical treatment of Alzheimer disease. The role of advanced glycation end products (AGEs) and its receptor RAGE have attracted increasing attention as the pivotal role of Aβ has been questioned. The present study was designed to test the neuroprotective effects of QFY, and the possible mechanism in AGE-induced Alzheimer model rats. After injection of AGE in the CA3 area of the hippocampus, QFY (8.6, 4.3, and 2.15 g·kg(-1)), and a positive control drug donepezil (2 mg·kg(-1)) were administrated through gastric intubation to rats once daily for thirty consecutive days. Another positive control group was the AGE + anti-RAGE group, which was simultaneously injected with anti-RAGE antibody before AGE treatment. The control group, sham-operated group, as well as the AGE + anti-RAGE group received saline at the same dosage. The Morris water maze test and the step-down passive avoidance test were conducted to evaluate the cognitive function of the rats. The expression of RAGE and NF-κB were assayed by immunohistochemical staining. The levels of Aβ, TNF-α, and IL-1β in the hippocampus were measured by enzyme-linked immunosorbent assay (ELISA). The results showed that QFY could significantly attenuate the memory impairment induced by AGE, decrease the expressions of RAGE and NF-κB, and reduce the levels of Aβ, TNF-α, and IL-1β in the hippocampus in a dose-dependent manner. Also, the blockage of RAGE could significantly reduce the impairments caused by AGEs. In conclusion, QFY could attenuate AGEs-induced, Alzheimer-like pathophysiological changes. These neuroprotective effects might be related to the RAGE/NF-κB pathway and its anti-inflammatory activity.
Subject(s)
Animals , Male , Alzheimer Disease , Drug Therapy , Metabolism , Amyloid beta-Peptides , Metabolism , Anti-Inflammatory Agents , Pharmacology , Therapeutic Uses , Brain , Metabolism , Dose-Response Relationship, Drug , Drugs, Chinese Herbal , Pharmacology , Therapeutic Uses , Glycation End Products, Advanced , Interleukin-1beta , Metabolism , Learning , Magnoliopsida , Memory Disorders , Drug Therapy , Metabolism , NF-kappa B , Metabolism , Phytotherapy , Plants, Medicinal , Rats, Sprague-Dawley , Receptor for Advanced Glycation End Products , Receptors, Immunologic , Metabolism , Signal Transduction , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
Objective To detect the expression of advanced glycation end-products (AGEs) in the sun exposure and non-exposure skin,to observe the elastic protein in the same location,and to explore the relationship between non-enzymatic glycation reactions and,photo-aging skin morphological changes.Methods In the exposure and non-exposure specimens from 30 patients,elastic fibers were stained with Gomori staining,and immunohistochemistry for AGEs was performed.Results AGEs expressed clearly positive in all elastic fibers of degeneration markedly (+ + above) of exposure skin,and appeared line-like in markedly(+ + above)elastic fibers.While in all non-exposure skin,AGEs expressed negative.In the exposure skin with middle or old age,compared with non-exposure skin,AGEs expressed more and elastic fibers were hyperplasia with thickening,curling and irregular distribution.The skin parts of AGEs expressed accorded with where elastic fibers degenerated.Conclusions Ultraviolet radiation can induce denaturation of elastic fibers and non-enzymatic glycation may contribute to the mechanism of skin photo-aging.
ABSTRACT
Objective: To investigate the effects of gastrodine (GAS) on the expression of IL-Iβ and IL-6 in nerve microglia BV-2 cell of mice induced by different concentrations of advanced glycation end products (AGEs) and GAS intervention. Methods: The cultured BV-2 cells of mice were divided into AGEs group, GAS (12.5, 25, 50, and 100 mg/L) groups, which were cultured for 18 h to observe the changes of cell morphology. The levels of IL-1β and IL-6 in the cell culture supernate were determined by enzyme linked immunosorbent assay (ELISA) and the expressions of IL-1β and mRNA were analysed by reverse transcriptase polymerase chain reaction (RT-PCR). Results: Observed under an inverted microscope, microglia is mostly quiescent and less protruding in control group; Most cell processes were more and amoeba-like in AGEs group, which was most obviously at the concentration of 300 mg/L. Cell processes in GAS groups reduced less than those in AGEs groups, of which the least was in GAS group at concentration of 50 mg/L. Compared with the control group, the levels of IL-1β and IL-6 in supernatants of cell culture in AGEs group and the expressions of IL-1β and IL-6 mRNA increased with significant difference (P<0.05). Compared with AGEs groups, the levels of IL-1β and IL-6 in supernatants of cell culture in AGEs group and the expressions of IL-1β and IL-6 mRNA obviously decreased, there were significant differences in AGE groups at the concentrations of 25, 50, and 100 mg/L (P<0.05), among which the decrease was most significant in the AGE group of 50 mg/L (P<0.01). Conclusion: AGEs could induce that nerve microglia produce IL-1β and IL-6 and GAS could partly inhibit the induction of AGEs on microglia.
ABSTRACT
BACKGROUND: Vascular Endothelial Growth Factor (VEGF) and Advanced Glycation End products (AGEs) have been implicated in the development of diabetic retinopathy. In this study, we examined the expression of VEGF and AGEs in the retina and serum, apoptosis in the retina, and lens opacities in streptozotocin (STZ)-induced diabetic rats. METHODS: The localization of VEGF and AGEs in the retina of STZ-induced diabetic rats was determined by immunohistochemical analysis, and apoptotic cell death was assessed using the TUNEL assay. In the serum, STZ-induced diabetic rats were assayed for VEGF and AGEs by ELISA. Lenses were also isolated to detect the opacity. RESULTS: Expression of VEGF and accumulation of AGEs were significantly increased in the retinal ganglion cell layers (GCL) and nuclear cell layers (NCL) of STZ-induced diabetic rats compared to normal control rats. In addition to cellular expression, serum VEGF and AGEs levels were also increased significantly in STZ-diabetic rats compared to normal rats (both P < 0.001) and there was a significant correlation between the serum VEGF and AGEs levels (r = 0.504). The lens opaque density of STZ-induced diabetic rats were significantly higher than in normal rats (P < 0.001). CONCLUSIONS: AGEs could be involved in the development of diabetic retinopathy through the induction of VEGF. One could possibly correlate this lens opaque formation with elevation of AGE induced VEGF level. Thus, this study should be considered as a basic research for studying pathology of the retina and lens in diabetic experimental models.
Subject(s)
Animals , Rats , Apoptosis , Cataract , Cell Death , Diabetic Retinopathy , Enzyme-Linked Immunosorbent Assay , In Situ Nick-End Labeling , Models, Theoretical , Retina , Retinal Ganglion Cells , Streptozocin , Vascular Endothelial Growth Factor AABSTRACT
Objective To evaluate the protective effects of the ethanol extract and fractions from Polygonatum odoratum on renal lesion in diabetic rats. Methods An experimental diabetic rat model was successfully induced by one ip injection of streptozotocin (STZ) at a dose of 60 mg/kg. Diabetic rats were ig administrated the ethanol extract or fractions for 80 d. Serum levels of creatinine (Cr), urea (Ur), glycosylation hemoglobin (GHb), renal advanced glycation end products (AGEs), and urinary albumin (UAL) excretion rate were determined by biochemical methods. Glomerular volume and renal pathological changes were observed by optic microscope. Results Treatments with the ethanol extract and chloroform fraction decreased the levels of GHb and UAL excretion rate, and inhibited renal AGEs formation and renal pathological changes in STZ-induced diabetic rats. Conclusion The ethanol extract and chloroform fraction have protective effects on renal lesion in diabetic rats, which might be related to inhibiting AGEs formation.
ABSTRACT
AIM To investigate the inhibitory effect of pycnogenol on generation of advanced glycation end products (AGEs) in vitro. METHODS Advanced glycation end products were determined by fluorospectrophotometer in the medium of 1 mol?L -1 glucose and 5% bovine albumin incubated at 37℃, 50℃, and 70℃ for different times. The inhibitory effect of pycnogenol was confirmed by the same system incubated with or without pycnogenol at different concentrations. RESULTS The rate of generation of AGEs in vitro was related with incubation time and incubation temperature. The generation of AGEs was inhibited by pycnogenol in vitro. The inhibitory rate was 10%～80% dependent on concentration and incubation time of pycnogenol. The inhibitory effect of pycnogenol on generation of AGEs was almost the same as that of Aminoguanidine at the same concentration. CONCLUSION pycnogenol could significantly inhibit generation of AGEs in vitro.