This study was aimed to investigate the effect of advanced glycosylation end products (AGE) on the proliferation of K562 and K562/A02 cells, the effect of tetrandrine (Tet) on proliferation of K562 and K562/A02 cells induced by AGE, and their mechanisms. The effects of AGE on proliferation of K562 and K562/A02 cells and Tet on the proliferation of AGE-induced K562 and K562/A02 cells were assayed by CCK8 kit, the apoptosis rate and the expression of receptor of advanced glycosylation end products (RAGE) in K562 and K562/A02 cells were determined by flow cytometry, the expression of RAGE mRNA was detected by semi-quantitative RT-PCR. The results showed that AGE could promote the proliferation of K562 and K562/A02 cells in a concentration-dependent manner, the cell proliferation was enhanced with time increasing in 0 - 48 h, and was higher than control group after 72 h. AGE up-regulated the RAGE mRNA and protein expressions of K562 and K562/A02 cells in a concentration-dependent manner. Treatment of Tet combined with AGE for 48 h could inhibit the proliferation of K562 and K562/A02 cells promoted by AGE in a concentration-dependent manner, which probably by inducing cell apoptosis, however, there was no obvious effect in the up-regulating expression of RAGE mRNA and protein induced by AGE. It is concluded that AGE can promote the proliferation of K562 and K562/A02 cells, which is probably induced by up-regulating the expression of RAGE mRNA and protein. Tet can inhibit the proliferation of K562 and K562/A02 cells induced by AGE, and the mechanism may be not closely associated with changes of the up-regulating expression of RAGE mRNA and protein induced by AGE.
Apoptosis ; drug effects ; Benzylisoquinolines ; pharmacology ; Cell Proliferation ; drug effects ; Gene Expression Regulation, Leukemic ; Glycation End Products, Advanced ; pharmacology ; Humans ; K562 Cells ; Receptor for Advanced Glycation End Products ; metabolism

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

OBJECTIVETo investigate the effects of advanced glycosylation end products (AGEs) modified bovine serum albumin (AGE-BSA) on the expression of reactive oxygen species (ROS) and monocyte chemoattractant protein-1 (MCP-1) in human renal mesangial cells (HRMCs).

METHODSHRMCs were cultured in vitro with medium containing different doses of AGE-BSA or BSA (50,100, 200, 400 mg/L) for 48 hours, or with AGE-BSA (200 mg/L) for different times (12, 24, 48, 72 h). Immunocytochemistry assay was used to estimate the protein level of RAGE. The ROS in cells were measured by flow cytometry and the mRNA expression of MCP-1 were analyzed by semi-quantiative reverse transcription-polymerase chain reaction (RT-PCR) after treatment with AGE-BSA or BSA.

RESULTSThe protein level of RAGE was upregulated in the HRMCs with AGE-BSA. The expression of ROS and MCP-1 significantly enhanced by incubation of AGE-BSA in a time- and dose-dependent manner. The effects of AGE-BSA-induced up-regulation of ROS and MCP-1 level was significantly blocked by neutralizing antibodies to RAGE, while the expression of ROS and MCP-1 stood nearly unchanged after cultured with huamn IgG.

CONCLUSIONThe expression of ROS and MCP-1 in HRMCs is induced by AGE-BSA through RAGE, which may have potential effects in the pathgenic mechanism of diabetic nephropathy.

Cells, Cultured ; Chemokine CCL2 ; metabolism ; Glycation End Products, Advanced ; pharmacology ; Humans ; Mesangial Cells ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism ; Serum Albumin, Bovine ; pharmacology

OBJECTIVETo investigate the accumulation of advanced glycation end products (AGEs) and expression of receptor for AGEs (RAGE) in streptozocin (STZ)-induced diabetic nephropathy in rats, and the role of antioxidants on the AGEs-RAGE signaling.

METHODSDiabetic rats were induced by once intraperitoneal injection of STZ at the dose of 60 mg/kg, and randomly divided into the DN group (n=12, treated with normal saline by intraperitoneal injection, once daily), the extract of Ginkgo biloba (EGb) group (n=14, treated with EGb 300 mg/kg by oral administration, once every other day), and the alpha-lipoic acid (ALA) group (n=12, treated with ALA at the dose of 35 mg/kg by intraperitoneal injection, once every other day). Rats of the normal control group (n=10) were given vehicle citrate buffer at the dose of 60 mg/kg. Rats were sacrificed at the 12th week and the 20th week of this study. The four groups were compared in terms of body weight, blood glucose, renal function, 24-h urine protein. Renal pathological changes were observed by PAS staining. Oxidative stress indices were detected using spectrophotometry. The concentrations of AGEs were measured using fluoro spectrophotometry, and the expressions of RAGE were detected by Real-time PCR and Western blot.

RESULTSCompared with the normal control group, the 24-h urine protein quantitation was higher and the glomerular filtration rate increased in rats at the 12th week and the 20th week. The pathological tissue staining showed dilated glomerular mesangium, proliferated glomerular matrix, vacuolar degeneration of the renal tubular epithelium. Malonaldehyde (MDA) levels and 8-hydroxide radical guanine deoxyriboside (8-OHdG) levels increased, and catalase (CAT) and reduced glutathione hormone (GSH) levels decreased. The AGEs contents in serum and renal tissue homogenate increased. The expressions of RAGE mRNA and protein increased in the DN group at the 12th and the 20th week. The 24-h urine protein quantitation was reduced in the EGb group and the ALA group, with alleviated pathological changes, lowered MDA and 8-OHdG levels, increased CAT and GSH levels, decreased AGEs contents, and down-regulated RAGE expressions.

CONCLUSIONSAGEs contents increased and RAGE expression up-regulated in the circulation and local renal tissues in DN rats. EGb and ALA could inhibit AGEs production and down-regulate RAGE expressions by reducing oxidative stress, thus further improving the renal tissue structure and renal functions of DN rats. It had better application prospect in treatment and prevention of DN.

Animals ; Antioxidants ; pharmacology ; Diabetes Mellitus, Experimental ; metabolism ; Diabetic Nephropathies ; metabolism ; Ginkgo biloba ; Glycation End Products, Advanced ; metabolism ; Kidney ; metabolism ; Male ; Rats ; Rats, Wistar ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; metabolism ; Thioctic Acid ; pharmacology

OBJECTIVETo study the effects of advanced glycosylation end products (AGEs) on the production of fibronectin (FN) in human peritoneal mesothelial cells (HPMC) in vitro and the role of protein kinase C (PKC) in this course.

METHODSThe AGE-human serum albumin (HSA) (0, 100, 500, 1 000 microg/ml) was used in culture medium to stimulate the HPMC. The mRNA level of FN was measured with real-time PCR, moreover, the protein level of FN in HPMC was detected by ELISA. With the method of ELISA, the PKC activities were observed. Inhibitors or activators of PKC were used to observe the roles of PKC pathways on the AGE-HSA stimulated productions of FN in HPMC.

RESULTSAGE-HSA activated PKC in HPMC in a dose, time-dependent manner (P < 0.05). AGE-HSA up-regulated the expression of FN mRAN and protein in dose- and time-dependently (P < 0.01); PKC activator phorbol 12-myristate 13-acetate (PMA) induced FN expression, respectively depletion of PKC and calphostin C, a PKC inhibitor, effectively prevented both PMA and AGE-HSA-induced expression of the FN (P < 0.05).

CONCLUSIONAGEs can increase the activities of PKC. AGEs can directly increase FN expression in HPMC which may contribute to peritoneal fibrosis and this is regulated by PKC.

Cells, Cultured ; Epithelium ; secretion ; Fibronectins ; metabolism ; Glycation End Products, Advanced ; pharmacology ; Humans ; Peritoneum ; cytology ; Protein Kinase C ; metabolism

OBJECTIVETo study the expression of the receptor for advanced glycation end products (RAGE) and the inhibitory effect of advanced glycation end products (AGEs) on testosterone production in rat Leydig cells.

METHODSRat Leydig cells were primarily cultured and the expression of RAGE in the Leydig cells was detected by RT-PCR and immunofluorescence staining. The Leydig cells were treated with AGEs at the concentrations of 25, 50, 100 and 200 microg/ml, respectively, and the testosterone content was determined by ELISA.

RESULTSRT-PCR and immunofluorescence staining exhibited the expression of RAGE in the rat Leydig cells. AGEs remarkably suppressed hCG-induced testosterone production in the Leydig cells in a concentration-dependent manner in the 50, 100 and 200 microg/ml groups as compared with the control (P < 0.01).

CONCLUSIONRAGE exists in rat Leydig cells and AGEs can significantly inhibit the secretion of testosterone in primarily cultured rat Leydig cells.

Animals ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Glycation End Products, Advanced ; pharmacology ; Leydig Cells ; metabolism ; radiation effects ; Male ; Rats ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Testosterone ; biosynthesis

Aging ; physiology ; Animals ; Arteries ; physiopathology ; Arteriosclerosis ; physiopathology ; Blood Pressure ; drug effects ; Diabetes Mellitus ; physiopathology ; Glycation End Products, Advanced ; antagonists & inhibitors ; metabolism ; physiology ; Guanidines ; pharmacology ; Humans ; Thiazoles ; pharmacology

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

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

OBJECTIVETo apply the synthesized advanced glycation end products (AGE) to the cultured human gingival fibroblast (HGF) in vitro and then to investigate the effects of AGE on the HGF proliferation and type I collagen synthesis and the potential impact of AGE in the repair of periodontium and its molecular mechanism in diabetes-associated periodontitis.

METHODSThe HGF was obtained from explants of human healthy gingival tissues by using tissue-explant technique. The AGE was prepared and then added to the culture media, its effect on HGF proliferation at different time duration was examined with MTT colorimetric assay. The type I collagen concentrations in cell culture supernatants and intracellular proteins were detected by ELISA, and the type I collagen mRNA expression of HGF was analyzed by real-time RT-PCR.

RESULTS200 mg/L AGE decreased the A value (P < 0.05) and changed the HGF shape. Incubation of HGF with AGE for 72 hours, the quantities of type I collagen were reduced (P < 0.05), and the expression of type I collagen mRNA was down-regulated (P < 0.05).

CONCLUSIONSThe AGE inhibited the HGF proliferation, decreased the synthesis of type I collagen and down-regulated the expression of type I collagen mRNA, impairing the repair of periodontium.

Cell Proliferation ; drug effects ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Fibroblasts ; cytology ; metabolism ; Gingiva ; cytology ; metabolism ; Glycation End Products, Advanced ; pharmacology ; Humans