OBJECTIVES: To investigate the mechanism by which Guijianyu ameliorates podocyte injury in a mouse model of diabetic kidney disease (DKD) induced by advanced glycation endproducts (AGEs). METHODS: Sixty db/db mouse models of DKD were randomized equally into 5 groups for treatment with saline, Guijianyu extract at 3 doses or irbesartan for 12 weeks, and the changes in renal pathology and structure were observed using transmission electron microscopy, and the expressions of related genes and key proteins were detected using RT-qPCR and immunohistochemistry. In cultured MPC-5 cells incubated with 50 mg/L AGEs-BSA for 24 h, the effect of different concentrations of Guijianyu extract on cell viability was examined with CCK-8 assay; Western blotting was performed to detect the protein expressions of RAGE, VEGFA, TNF-α, NF-κB(p65), IL-6 and caspase-3, and the mRNA expressions of RAGE, NF-κB (p65), VEGFA and IL-6 were detected with RT-qPCR. RESULTS: In mouse models of DKD, treatment with high-dose Guijianyu extract significantly reduced renal expressions of RAGE, VEGFA, NF-κB(p65), and IL-6 proteins and the mRNA expressions of RAGE, NF-κB, and IL-6. In MPC-5 cells, exposure to AGEs significantly reduced cell viability and increased the protein expressions of RAGE, NF‑κB (p65), VEGFA, TNF-α, IL-6 and caspase-3 (P<0.05) and mRNA expressions of RAGE, NF-κB (p65), VEGFA, and IL-6. Treatment with Guijianyu extract obviously improved cell viability and reduced the expressions of RAGE, NF-κB(p65), VEGFA, TNF-α, IL-6, and caspase-3. Furthermore, Guijianyu extract effectively reversed RAGE agonist-induced elevation of protein expressions of RAGE, VEGFA, TNF-α, IL-6, and caspase-3 and mRNA expressions of RAGE, NF-κB (p65), IL-6, and VEGFA in MPC-5 cells. CONCLUSIONS Guijianyu extract ameliorates AGEs-induced mouse renal podocyte injury in DKD by inhibiting the activation of AGEs-RAGE signaling pathway and reducing the expressions of pro-inflammatory cytokines and vascular endothelial growth factors.
Animals ; Glycation End Products, Advanced ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Signal Transduction/drug effects* ; Podocytes/pathology* ; Diabetic Nephropathies/drug therapy* ; Receptor for Advanced Glycation End Products ; Vascular Endothelial Growth Factor A/metabolism* ; Interleukin-6/metabolism* ; Male

OBJECTIVE: The present study investigated antiglycation and antioxidant activities of crude dry extract and saponin fraction of Tribulus terrestris. It also developed a method of microencapsulation and evaluated antiglycation and antioxidant activities of crude dry extract and saponin fraction before and after microcapsule release. METHODS: Antiglycation activity was determined by relative electrophoretic mobility (REM), free amino groups and inhibition of advanced glycation end-product (AGE) formation. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion-reducing antioxidant power (FRAP), nitric oxide (NO) and thiobarbituric acid reactive species (TBARS) tests. Microcapsules were prepared using maltodextrin as wall material and freeze-drying as encapsulation technique. Morphological characterization of microcapsules was evaluated by scanning electron microscopy, and encapsulation efficiency and microcapsule release were determined by total saponins released. Antiglycation and antioxidant assays were performed using crude dry extract and saponin fraction of T. terrestris before and after release. RESULTS: Saponin fraction showed an increase of 32.8% total saponins. High-performance liquid chromatography-mass spectrometry analysis showed the presence of saponins in the obtained fraction. Antiglycation evaluation by REM demonstrated that samples before and after release presented antiglycation activity similar to bovine serum albumin treated with aminoguanidine. Additionally, samples inhibited AGE formation, highlighting treatment with saponin fraction after release (89.89%). Antioxidant tests demonstrated antioxidant activity of the samples. Crude dry extract before encapsulation presented the highest activities in DPPH (92.00%) and TBARS (32.49%) assays. Saponin fraction before encapsulation in FRAP test (499 μmol Trolox equivalent per gram of dry sample) and NO test (15.13 μmol nitrite formed per gram of extract) presented the highest activities. CONCLUSION This study presented antiglycation activity of crude dry extract and saponin fraction of T. terrestris, besides it demonstrated promising antioxidant properties. It also showed that the encapsulation method was efficient and maintained biological activity of bioactive compounds after microcapsule release. These results provide information for further studies on antidiabetic and antiaging potential, and data for new herbal medicine and food supplement formulations containing microcapsules with crude extract and/or saponin fraction of T. terrestris.
Antioxidants/chemistry* ; Capsules ; Complex Mixtures ; Glycation End Products, Advanced ; Plant Extracts/pharmacology* ; Saponins/pharmacology* ; Thiobarbituric Acid Reactive Substances ; Tribulus

OBJECTIVES: Excessive production of AGEs in diabetic patients will affect the normal function of osteoblasts, and this process may be related to autophagy of osteoblasts. This study aims to explore the effect of advanced glycation end products (AGEs) on autophagic activity during osteogenic differentiation in rat bone marrow mesenchymal stem cells (BMSCs). METHODS: BMSCs were isolated and cultured in vitro, treated with different concentrations (0, 50, 100, 200, and 400 mg/L) of AGEs for different time (3, 6, 12, 24, 48, and 72 h). The proliferation activity was detected by CCK-8 method. The mRNA and protein expression levels of Beclin1 and LC3 in cells were detected by real-time PCR and Western blotting, respectively.The autophagic vacuoles were observed under the transmission electron microscope. The cells were treated with autophagy promoter rapamycin or autophagy inhibitor 3MA. After 7 days of osteogenic induction, we performed alkaline phosphatase (ALP) staining and real-time PCR to detect the mRNA expression levels of osteogenesis-related genes. RESULTS: In the low-concentration groups, the proliferation activity in BMSCs was increased ( CONCLUSIONS Low concentration of AGEs can enhance the proliferative activity of BMSCs and promote osteogenic differentiation by accelerating autophagy. High concentration of AGEs can suppress the proliferation of BMSCs and inhibit osteogenic differentiation by reducing autophagy.
Animals ; Autophagy ; Bone Marrow Cells ; Cell Differentiation ; Cells, Cultured ; Glycation End Products, Advanced/pharmacology* ; Humans ; Osteoblasts ; Osteogenesis ; Rats ; Rats, Sprague-Dawley

To investigate the potential molecular markers and drug-compound-target mechanism of Mahuang Shengma Decoction(MHSM) in the intervention of acute lung injury(ALI) by network pharmacology and experimental verification. Databases such as TCMSP, TCMIO, and STITCH were used to predict the possible targets of MHSM components and OMIM and Gene Cards were employed to obtain ALI targets. The common differentially expressed genes(DEGs) were therefore obtained. The network diagram of DEGs of MHSM intervention in ALI was constructed by Cytoscape 3. 8. 0, followed by Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses of target genes. The ALI model was induced by abdominal injection of lipopolysaccharide(LPS) in mice. Bronchoalveolar lavage fluid(BALF) was collected for the detection of inflammatory factors. Pathological sectioning and RT-PCR experiments were performed to verify the therapeutic efficacy of MHSM on ALI. A total of 494 common targets of MHSM and ALI were obtained. Among the top 20 key active compounds of MHSM, 14 from Ephedrae Herba were found to be reacted with pivotal genes of ALI [such as tumor necrosis factor(TNF), tumor protein 53(TP53), interleukin 6(IL6), Toll-like receptor 4(TLR4), and nuclear factor-κB(NF-κB)/p65(RELA)], causing an uncontrolled inflammatory response with activated cascade amplification. Pathway analysis revealed that the mechanism of MHSM in the treatment of ALI mainly involved AGE-RAGE, cancer pathways, PI3 K-AKT signaling pathway, and NF-κB signaling pathway. The findings demonstrated that MHSM could dwindle the content of s RAGE, IL-6, and TNF-α in the BALF of ALI mice, relieve the infiltration of inflammatory cells in the lungs, inhibit alveolar wall thickening, reduce the acute inflammation-induced pulmonary congestion and hemorrhage, and counteract transcriptional activities of Ager-RAGE and NF-κB p65. MHSM could also synergically act on the target DEGs of ALI and alleviate pulmonary pathological injury and inflammatory response, which might be achieved by inhibiting the expression of the key gene Ager-RAGE in RAGE/NF-κB signaling pathway and downstream signal NF-κB p65.
Acute Lung Injury/genetics* ; Animals ; Drugs, Chinese Herbal/pharmacology* ; Lipopolysaccharides ; Lung/metabolism* ; Mice ; NF-kappa B/metabolism* ; Network Pharmacology ; Receptor for Advanced Glycation End Products/metabolism* ; Signal Transduction

Objective To investigate the effects of simvastatin on diabetic neuropathic pain and systematic inflammation in diabetic rats and explore their molecular mechanisms.Methods Totally 24 rats were equally randomized into the normal+vehicle(NV)group,diabetic+vehicle(DV)group,and diabetic+simvastatin(DS)group using the random number table.Streptozotocin(STZ)was used to establish the rat models of diabetes.Blood glucose,body mass,paw withdrawal mechanical threshold(PWMT),and paw withdrawal thermal latency(PWTL)in each group were observed on days 7,14,21,and 28 after STZ injection.On day 28 after STZ injection,rats were sacrificed,and the lumbar spinal dorsal horn and serum were collected.Western blotting was used to detect the expression of receptor for advanced glycation end products(RAGE)and the phosphorylation levels of protein kinase B(AKT),extracellular signal-regulated kinase(ERK),p38,and c-Jun N-terminal kinase(JNK)in the spinal dorsal horn of rats in each group.Enzyme-linked immunosorbent assay was performed to determine the serum concentrations of oxidized low density lipoprotein(ox-LDL)and interleukin-1β(IL-1β).Results On days 14,21 and 28 after STZ injection,the PWMT in DV group were(8.6 ± 0.8),(7.1 ± 1.6),and(7.8 ± 0.8)g respectively,which were significantly lower than (12.0 ± 0.9)(=8.482, =0.000),(11.6 ± 1.5)(=11.309, =0.000),and(11.7 ± 1.5)g(=9.801, =0.000)in NV group.The PWMT in DS group on days 21 and 28 were(9.4 ± 1.4)(=5.780, =0.000)and(9.7 ± 0.9)g(=4.775, =0.003),respectively,which were significantly improved comparing with those of DV group.On days 7,14,21,and 28,there were no significant differences in PWTL among these three groups (all <0.05).The expression of RAGE in the spinal dorsal horn of DV group was significantly higher than those of NV group(=6.299, =0.000)and DS group(=2.891, =0.025).The phosphorylation level of AKT in the spinal dorsal horn of DV group was significantly higher than those of NV group(=8.915,=0.000)and DS group(=4.103,=0.003).The phosphorylation levels of ERK( =8.313,=0.000),p38( =2.965, =0.022),and JNK(=7.459, =0.000)in the spinal dorsal horn of DV group were significantly higher than those of NV group;the phosphorylation level of JNK in the spinal dorsal horn of DS group was significant lower than that of DV group(=3.866, =0.004);however,there were no significant differences in the phosphorylation levels of ERK(=1.987,=0.122)and p38(=1.260,=0.375)in the spinal dorsal horn between DS group and DV group.The serum concentrations of ox-LDL and IL-1β in DV group were(41.86 ± 13.40)ng/ml and(108.16 ± 25.88)pg/ml,respectively,which were significantly higher than those in NV group [(24.66 ± 7.87)ng/ml(=3.606,=0.003)and(49.32 ± 28.35)pg/ml(=5.079,=0.000)] and DS group [(18.81 ± 5.62)ng/ml (=4.833, =0.000)and(32.73 ± 11.73)pg/ml(=6.510, =0.000)].Conclusions Simvastatin can relieve the mechanical allodynia of diabetic rats possibly by inhibiting the activation of RAGE/AKT and the phosphorylation of JNK in the spinal dorsal horn.Simvastatin can also decrease the serum concentrations of ox-LDL and IL-1β in diabetic rats,which may contribute to the relief of systematic inflammation.
Animals ; Diabetes Mellitus, Experimental ; complications ; Hyperalgesia ; Inflammation ; drug therapy ; Interleukin-1beta ; blood ; Lipoproteins, LDL ; blood ; Neuralgia ; drug therapy ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor for Advanced Glycation End Products ; metabolism ; Simvastatin ; pharmacology

OBJECTIVEMyanmar has a long history of using medicinal plants for treatment of various diseases. To the best of our knowledge there are no previous reports on antiglycation activities of medicinal plants from Myanmar. Therefore, this study was aimed to evaluate the antioxidant, antiglycation and antimicrobial properties of 20 ethanolic extracts from 17 medicinal plants indigenous to Myanmar.

METHODSIn vitro scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide (SO) radicals were used to determine the antioxidant activities. Folin-Ciocalteu's method was performed to determine the total phenolic content. Antiglycation and antimicrobial activities were detected by bovine serum albumin-fluorescent assay and agar well diffusion method.

RESULTSTerminalia chebula Retz. (Fruit), containing the highest total phenolic content, showed high antioxidant activities with inhibition of 77.98% ± 0.92%, 88.95% ± 2.42%, 88.56% ± 1.87% and 70.74%± 2.57% for DPPH, NO, SO assays and antiglycation activity respectively. It also showed the antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans with inhibition zone of 19, 18, 17, 25 and 15 mm, respectively. Garcinia mangostana Linn. showed the strongest activities for SO and antiglycation assays with inhibition of 93.68% ± 2.63% and 82.37% ± 1.78%. Bark of Melia sp. was the best NO radical scavenger with inhibition rate of 89.39%± 0.60%.

CONCLUSIONThe results suggest that these plants are potential sources of antioxidants with free radical-scavenging and antiglycation activities and could be useful for decreasing the oxidative stress and glycation end-product formation in glycation-related diseases.

Anti-Bacterial Agents ; analysis ; pharmacology ; Anti-Infective Agents ; analysis ; pharmacology ; Antioxidants ; analysis ; pharmacology ; Bacteria ; drug effects ; growth & development ; Biphenyl Compounds ; metabolism ; Candida albicans ; drug effects ; growth & development ; Fruit ; Garcinia ; chemistry ; Glycation End Products, Advanced ; metabolism ; Humans ; Magnoliopsida ; chemistry ; Medicine, Traditional ; Melia ; chemistry ; Myanmar ; Nitric Oxide ; metabolism ; Oxidative Stress ; drug effects ; Phenols ; analysis ; pharmacology ; Phytotherapy ; Picrates ; metabolism ; Plant Bark ; Plant Extracts ; chemistry ; pharmacology ; Plants, Medicinal ; Superoxides ; Terminalia ; chemistry

The present study was designed to evaluate the therapeutic potential of bioactive compounds from chloroform extract of the leaves of Hylocereus undatus in the formation of advanced glycation end products (AGEs) in vitro. Bioactivity-guided fractionation of chloroform extract from Hylocereus undatus afforded two novel 12-ursen-type triterpenes, 3β, 16α, 23-trihydroxy-urs-12- en-28-oic acid (1) and 3β, 6β, 19α, 22α-tetrahydroxy-urs-12-en-28-oic acid (2), as well as four known triterpenes 2α, 3β, 23-tetrahydroxy-urs-11-en-28-oic acid (3), 3β-acetoxy-28-hydroxyolean-12-ene (4), 3β, 16α-dihidroxyolean-12-ene (5) and 3β-acetoxy-olean-12-ene (6). Our results revealed that triterpenes 1-3 were able to inhibit the formation of AGEs in all tested assays. The data indicated that the triterpenes had inhibitory activity at the múltiple stages of glycation and that there might be a high potential for decreasing protein oxidation and protein glycation that can enhance glycative stress in diabetic complications.
Cactaceae ; chemistry ; Glycation End Products, Advanced ; chemistry ; Glycosylation ; drug effects ; Molecular Structure ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Plant Leaves ; chemistry ; Triterpenes ; chemistry ; isolation & purification ; pharmacology

OBJECTIVETo investigate the role of p38MAPK signaling pathway in the mechanism by which glucagon-like peptide-1 (GLP-1) inhibits endothelial cell damage induced by AGEs.

METHODSHuman umbilical vein endothelial cells were divided into control group, AGEs group, GLP-1 group, AGEs+GLP-1 group, AGEs+inhibitor group, and AGEs+GLP-1+inhibitor group. The expressions of p-p38MAPK/p38MAPK and p-eNOS/eNOS protein were examined by Western blotting, and the cell apoptosis rates were tested by flow cytometry.

RESULTSCompared with the control group, AGEs significantly enhanced the expression of p-p38 MAPK protein (P=0.001) while GLP-1 significantly inhibited its expression (P<0.001). AGEs significantly inhibited the expression of p-eNOS protein (P=0.007), which was enhanced by GLP-1 and p38 MAPK inhibitor (SB203580) (P=0.004). Both SB203580 and GLP-1 treatment decreased the apoptosis rate of AGEs-treated cells (P<0.001).

CONCLUSIONGLP-1 can protect human umbilical vein endothelial cells against AGEs-induced apoptosis partially by inhibiting the phosphorylation of p38MAPK protein and promoting the expression of p-eNOS protein.

Apoptosis ; Cells, Cultured ; Glucagon-Like Peptide 1 ; pharmacology ; Glycation End Products, Advanced ; metabolism ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; Humans ; Nitric Oxide Synthase Type III ; metabolism ; Phosphorylation ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo investigate the effect of metformin in protecting against advanced glycation end products (AGEs)-induced apoptosis in human primary dermal fibroblasts.

METHODSFibroblasts were exposed to 100, 200, or 300 µg/mL AGEs, 300 µg/mL bovine serum albumin (BSA), or 300 µg/mL AGEs and 1 mmol/L metformin for 24, 48, or 72 h. The exposed cells were examined for cell apoptosis using a cell counting kit. The expressions of caspase-3, Bax and Bcl-2 protein in the fibroblasts treated for 72 h were detected with Western blotting.

RESULTSAGEs exposures caused significant dose- and time-dependent apoptosis in the fibroblasts. A 72-h exposure to 300 µg/mL AGEs resulted in obviously increased apoptosis of the fibroblasts compared to the control group (0.72 ± 0.02 vs 1 ± 0.04, P<0.05), and metformin significantly decreased AGEs-induced apoptosis (0.98 ± 0.02 vs 0.72 ± 0.02, P<0.05). The expressions of caspase-3 and Bax protein were significantly increased (P<0.05) and Bcl-2 protein expression was decreased (P<0.05) with a lowered Bcl-2/Bax ratio in AGEs-treated fibroblasts (P<0.05), and such changes were significantly reversed by metformin treatment (P<0.05).

CONCLUSIONMetformin can antagonize AGEs-induced apoptosis in human dermal fibroblasts by regulating the expressions of caspase-3, Bax and Bcl-2.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cells, Cultured ; Dermis ; cytology ; Fibroblasts ; cytology ; drug effects ; Glycation End Products, Advanced ; adverse effects ; Humans ; Metformin ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo explore the change of RAGE-NF-κB signaling pathway during the course of hyperoxia-induced lung injury in newborn rats, and the effect of glucocorticoid on this pathway.

METHODSTwenty-four Sprague-Dawley neonatal rats were randomly divided into three groups (n=8 each) : sham control (control group), hyperoxia-induced acute lung injury (model group) and glucocorticoid-treated acute lung injury (glucocorticoid group). Rats were sacrificed at 13 days after birth. RAGE and NF-κB expression levels in lung tissues were detected by reverse transcription polymerase chain reaction, Western blot and immunohistochemistry analysis. The levels of tumor necrosis factor α (TNF-α) and sRAGE in bronchoalveolar lavage fluid (BALF) and serum were measured using ELISA. Lung damage was evaluated by histological examinations.

RESULTSRAGE and NF-κB mRNA and protein expression levels in lung tissues were significantly increased in the model and glucocorticoid groups compared with the control group (P<0.05). Serum RAGE concentrations were significantly increased but RAGE concentrations in BALF were significantly reduced in the model and glucocorticoid groups compared with the control group (P<0.05). RAGE and NF-κB expression at both mRNA and protein levels in lung tissues was significantly lower in the glucocorticoid group than in the model group (P<0.05). RAGE concentrations were significantly lower in serum (P<0.05), but were higher in BALF (P<0.05) in the glucocorticoid group than in the model group.

CONCLUSIONSRAGE-NF-κB pathway plays an important role in hyperoxia-induced lung injury in neonatal rats, and glucocorticoid administration may play a protective role against the lung injury by down-regulating RAGE-NF-κB signaling pathway.

Animals ; Animals, Newborn ; Glucocorticoids ; pharmacology ; Hyperoxia ; complications ; Lung Injury ; prevention & control ; NF-kappa B ; analysis ; genetics ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; analysis ; genetics ; physiology ; Signal Transduction ; drug effects ; Tumor Necrosis Factor-alpha ; analysis