Genistein inhibits advanced glycation end product formation by trapping methylglyoxal

Methylglyoxal (MGO) is a highly reactive endogenous metabolite derived from several nonenzymatic and enzymatic reactions, and identified as a well-known precursor of advanced glycation end products (AGEs). In the present study, genistein, a naturally occurring isoflavone derived from soy products, demonstrated significant trapping effects of MGO and consequently formed mono- and di-MGO adducts under physiological conditions (pH 7.4, 37 °C). More than 80.0% of MGO was trapped within 4 h, and the trapping efficiency could be up to 97.7% at 24 h. The reaction adducts formed from genistein and MGO under different ratios were analyzed using LC/MS. We also successfully purified and identified the major mono- and di-MGO conjugated adducts of genistein. The NMR data showed that positions 6 and 8 of the A ring of genistein were the major active sites for trapping MGO. We further demonstrated that genistein could effectively inhibit the formation of AGEs in the human serum albumin (HSA)-MGO assay. Two mono-MGO adducts and one di-MGO adduct of genistein were detected in this assay using LC/MS. The di-MGO adduct of genistein became the dominant reaction product during prolonged incubation. Results from this study, as well as our previous findings on (-)-epigallocatechin 3-gallate (EGCG), phloridzin and phloretin, indicate that dietary flavonoids that have the same A ring structure as genistein, EGCG, phloridzin, and phloretin may have the potential to inhibit the formation of AGEs by trapping reactive dicarbonyl species.     

Antihyperglycemic and antihyperlipidemic effect of Santalum album in streptozotocin induced diabetic rats

Context: Santalum album Linn (Santalaceae), commonly known as Sandalwood is used traditionally for its antihyperlipidemic and diuretic activity.

Objective: This study investigated the antihyperglycemic and antihyperlipidemic effect of long-term oral administration of the Santalum album pet ether fraction in streptozotocin-induced diabetic rats.

Materials and methods: Diabetes was induced by a single intraperitoneal injection of streptozotocin at 70?mg/kg body weight. Rats were treated with Santalum album pet ether fraction orally at a dose of 10 µg/kg body weight twice daily for 60 days. Metformin (30?mg/kg body weight) was used as positive control. Lipid profile and glycated hemoglobin were estimated. HPLC profiling of Santalum album pet ether fraction was carried out.

Results and discussion: Treatment of diabetic rats for 60 days demonstrated reduction in blood glucose level by 140?mg/dl. Metformin treated group showed a decrease in blood glucose by 70?mg/dl, as against an increase in diabetic control group by 125?mg/dl. Total cholesterol (TC), low density lipoprotein (LDL) and triglyceride (TG) levels were decreased by 22, 31 and 44%, respectively, in treated diabetic rats whereas, cardioprotective, high density lipoprotein (HDL) increased by 46%. In case of metformin, the values were 11, 29 and 15% respectively, while HDL increased by 7%. Significant improvement in atherogenic index from 267 to 139% was observed in treated rats.

Conclusion: Santalum album pet ether fraction has potential antihyperlipidemic activity that can help in overcoming insulin resistance.     

西红花酸对糖尿病大鼠体内晚期糖基化终产物的形成及其受体表达的影响

目的:观察西红花酸对糖尿病(diabetic melli-tus,DM)大鼠晚期糖基化终产物(AGEs)的形成和受体(RAGE)蛋白表达的影响。方法:以链脲佐菌素诱导DM大鼠模型,并将DM大鼠随机分为DM模型组和西红花酸治疗组(50 mg.kg-1.d-1),另设正常组,给药21 d后,血糖仪测定大鼠空腹血糖;试剂盒分别测定AGEs中间产物即血清果糖胺(FMN)和糖化血红蛋白(GHb)的含量;荧光分光光度法测定主动脉及肠系膜血管床AGEs的水平;病理切片观察肠系膜动脉的变化;免疫组化法检测RAGE蛋白在肠系膜动脉中的表达。结果:西红花酸治疗后,对DM大鼠血糖值无明显影响;但FMN和GHb水平与模型组比明显下降;AGEs在主动脉和肠系膜血管床中沉积减少;肠系膜动脉血管损伤减轻;RAGE蛋白表达显著下降。结论:西红花酸可抑制蛋白质非酶糖化反应,减少AGEs及其中间产物的形成,下调RAGE蛋白表达,保护DM大鼠血管。     

Reaction of metformin with dicarbonyl compounds. Possible implication in the inhibition of advanced glycation end product formation

Dicarbonyl compounds such as methylglyoxal and glyoxal are extremely reactive glycating agents involved in the formation of advanced glycation end products (AGEs), which in turn are associated with diabetic vascular complications. Guanidino compounds such as aminoguanidine appear to inhibit AGE formation by reacting with alpha-dicarbonyl compounds. The aim of this work was to study whether the antihyperglycemic agent metformin (a guanidine-like compound) might react with reactive alpha-dicarbonyls. Metformin was incubated at pH 7.4 and 37 degrees in the presence of either methylglyoxal or glyoxal and reaction products analysed by HPLC coupled to mass tandem spectrometry. AGE formation on albumin by methylglyoxal and glyoxal in the presence or absence of metformin was also studied by measuring the fluorescence at 370/440 nm after albumin-AGE isolation by ultrafiltration. As a standard for mass spectra analysis, a metformin-methylglyoxal adduct was chemically synthesised and characterised as a triazepinone (2-amino-4-(dimethyl-amino)-7-methyl-5,7-dihydro-6H-[1,3,5]triazepin+ ++-6-one). The results obtained showed that metformin strongly reacted with methylglyoxal and glyoxal, forming original guanidine-dicarbonyl adducts. Reaction kinetic studies as well as mass fragmentation spectra of the reaction products were compatible with the presence of triazepinone derivatives. In the presence of metformin, AGE-related fluorescence after albumin incubation with either glyoxal or methylglyoxal was decreased by 37% and 45%, respectively. These results suggest that besides its known antihyperglycemic effect, metformin could also decrease AGE formation by reacting with alpha-dicarbonyl compounds. This is relevant to a potential clinical use of metformin in the prevention of diabetic complications by inhibition of carbonyl stress.     

Hypolipidemic effect of Cuminum cyminum L. on alloxan-induced diabetic rats.

Hyperlipidemia is an associated complication of diabetes mellitus. Many spices and herbs are known to be hypoglycaemic. Cuminum cyminum belonging to the family Apiaceae is widely used in Ayurvedic medicine for the treatment of dyspepsia, diarrhoea and jaundice. The present work was done to study the role of C. cyminum supplementation on the plasma and tissue lipids in alloxan diabetic rats. Oral administration of 0.25 g kg(-1) body weight of C. cyminum for 6 weeks to diabetic rats resulted in significant reduction in blood glucose and an increase in total haemoglobin and glycosylated haemoglobin. It also prevented a decrease in body weight. C. cyminum treatment also resulted in a significant reduction in plasma and tissue cholesterol, phospholipids, free fatty acids and triglycerides. Histological observations demonstrated significant fatty changes and inflammatory cell infiltrates in diabetic rat pancreas. But supplementation with C. cyminum to diabetic rats significantly reduced the fatty changes and inflammatory cell infiltrates. Moreover, C. cyminum supplementation was found to be more effective than glibenclamide in the treatment of diabetes mellitus.     

Antihyperglycemic activity and antidiabetic effect of methyl caffeate isolated from Solanum torvum Swartz. fruit in streptozotocin induced diabetic rats

Natural remedies from medicinal plants are considered to be effective and safe alternatives to treat diabetes mellitus. Solanum torvum Swartz. fruit is widely used in the traditional system of medicine to treat diabetes. In the present study methyl caffeate, isolated from S. torvum fruit, was screened for its efficacy in controlling diabetes in animal models. Antihyperglycemic effect of methyl caffeate was studied in normal glucose-fed rats. The effects of oral administration of methyl caffeate (10, 20 and 40 mg/kg) for 28 days on body weight, fasting blood glucose, plasma insulin, hemoglobin, glycated hemoglobin, total protein, hepatic glycogen and carbohydrate metabolism enzymes in streptozotocin induced diabetic rats were investigated. Histological observations in the pancreas and GLUT4 expression in skeletal muscles were also studied. Methyl caffeate at 40 mg/kg significantly prevented the increase in blood glucose level after glucose administration at 60 min in comparison to the hyperglycemic control group. In streptozotocin induced diabetic rats, methyl caffeate produced significant reduction in blood glucose and increased body weight. The levels and/or activities of other biochemical parameters were near normal due to treatment with methyl caffeate. Methyl caffeate treated diabetic rats showed upregulation of GLUT4 and regeneration of β-cells in the pancreas. These results substantiated that methyl caffeate possessed hypoglycemic effect, and it could be developed into a potent oral antidiabetic drug.     

Effect of green tea extract on advanced glycation and cross-linking of tail tendon collagen in streptozotocin induced diabetic rats.

Diabetes leads to modification of collagen such as advanced glycation and cross-linking which play an important role in the pathogenesis of diabetes mellitus. We have investigated the effect of green tea on modification of collagen in streptozotocin (60 mg/kg body weight) induced diabetic rats. To investigate the therapeutic effect of green tea, treatment was begun six weeks after the onset of diabetes and green tea extract (300 mg/kg body weight) was given orally for 4 weeks. The collagen content, extent of advanced glycation, advanced glycation end products (AGE) and cross-linking of tail tendon collagen were investigated. Green tea reduced the tail tendon collagen content which increased in diabetic rats. Accelerated advanced glycation and AGE in diabetic animals, as detected by Ehrlich's-positive material and collagen linked fluorescence respectively were reduced significantly by green tea. The solubility of tail tendon collagen decreased significantly in diabetic rats indicating a remarkable increase in the cross-linking, whereas green tea increases the solubility of collagen in diabetic rats. The present study reveals that green tea is effective in reducing the modification of tail tendon collagen in diabetic rats. Thus green tea may have a therapeutic effect in the treatment of glycation induced complications of diabetes.     

槲皮素脂质体对糖尿病大鼠肾脏糖基化终产物及其受体表达的影响

摘要： 目的 观察槲皮素脂质体 （LQ） 对糖尿病大鼠肾脏糖基化终产物 （AGEs） 及其受体 （RAGE） 表达的影响。方法 采用旋转蒸发法制备槲皮素脂质体, 高糖高脂饲料联合腹腔注射链脲佐菌素 （STZ） 建立 2 型糖尿病大鼠模型, 并随机分为糖尿病模型组 （DM 组）, 槲皮素脂质体低 （LQ-L）、 中 （LQ-M）、 高 （LQ-H） 剂量组, 氨基胍 （AG） 对照组（AG 组）, 另设正常组 （N 组）。灌胃治疗 8 周后测定各组大鼠血糖、 体质量、 肾脏肥大指数 （KI）、 血尿素氮 （BUN）、 血肌酐 （Scr）, ELISA 法测血清 AGEs 表达和 24 h 尿微量白蛋白, PAS 染色观察肾脏病理改变, 免疫组化测肾组织 AGEs 表达, RT-PCR 检测肾皮质 RAGE mRNA 表达水平。结果 与 N 组比较, DM 组大鼠血糖、 KI、 BUN、 Scr、 血清 AGEs 和 24 h 尿微量白蛋白显著升高, 体质量明显降低; 肾小球体积萎缩, 基底膜增厚; 肾组织 AGEs 和 RAGE mRNA 表达增高 （均 P < 0.05）。与 DM 组比较, LQ 各剂量组大鼠血糖、 KI、 BUN、 Scr、 血清 AGEs 和 24 h 尿微量白蛋白均降低, 体质量增加; 病理改变明显减轻; 肾组织 AGEs 和 RAGE mRNA 表达降低, 以中剂量组作用更明显 （均 P < 0.05）。结论 LQ 可抑制蛋白质非酶糖基化反应, 从而减少肾组织 AGEs 生成及 RAGE mRNA 表达水平, 对糖尿病大鼠肾脏具有保护作用。     

Role of advanced glycation end products in diabetic neuropathy

Diabetic neuropathy is the commonest form of peripheral neuropathy in the developed countries of the world. In diabetic patients, the presence of peripheral neuropathy increases their risks for developing foot ulceration and subsequent necrosis that necessitates lower limb amputation. Although the precise mechanisms underlying diabetic neuropathy remain unclear, there is evidence that hyperglycemia-induced formation of advanced glycation end products (AGEs) is related to diabetic neuropathy; AGE-modified peripheral nerve myelin is susceptible to phagocytosis by macrophages and contributes to segmental demyelination; modification of major axonal cytoskeletal proteins such as tubulin, neurofilament, and actin by AGEs results in axonal atrophy/degeneration and impaired axonal transport; and glycation of extracellular matrix protein laminin leads to impaired regenerative activity in diabetic neuropathy. Recently, the receptor for AGEs (RAGE) has been found to colocalize with AGEs in diabetic peripheral nerves. This suggests that, in diabetic neuropathy, AGEs and AGE/RAGE interactions induce oxidative stress, result in upregulation of nuclear factor (NF)-kappaB and various NF-kappaB-mediated proinflammatory genes, and exaggerate neurological dysfunction, including altered pain sensation. Additionally, AGE/RAGE-induced oxidative stress further accelerates formation of glycoxidation products such as Nepsilon-(carboxymethyl)lysine and pentosidine. Although new drugs that inhibit the formation of AGEs and block the AGE-RAGE interaction are being studied, no effective treatment modalities against AGE-induced nerve injury are currently available clinically. A therapeutic strategy to prevent and ameliorate diabetic neuropathy using anti-AGE agents needs to be established. In this review, the current issues involved in the role of the glycation process and the potential treatment options for diabetic neuropathy are explored.     

晚期糖基化终产物与糖尿病足的关系

相比于非糖尿病患者而言,糖尿病患者足部溃疡发生的几率显著增加,自我愈合的可能性很低,转变成难治性溃疡的可能性显著增加,截肢(趾)率增加2～4倍.尽管其原因很多,但其中之一应该是与糖尿病患者长期慢性持续的血糖增高有密切关系.     

Antidiabetic activity of Momordica charantia seeds on streptozotocin induced diabetic rats

The present study was aimed to evaluate the hypoglycemic efficacy in an aqueous extract of seeds of two varieties, namely a country and a hybrid variety of Momordica charantia (MCSEt1 and MCSEt2) respectively in streptozotocin (STZ) induced diabetic rats. STZ-induced diabetic rats were treated with aqueous extracts of MCSEt1 and t2 for a period of 30 days. MCSEt1 and t2 extract treatment to diabetic rats resulted in a significant reduction in blood glucose, glycosylated hemoglobin, lactate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase and glycogen phosphorylase, and a concomitant increase in the levels of hemoglobin, glycogen and activities of hexokinase and glycogen synthase. These results clearly show the antidiabetic properties of Momordica charantia. Both the varieties showed safe and significant hypoglycemic effects which were more pronounced in MCSEt1 compared to MCSEt2 and glibenclamide.     

Antihyperglycemic activity of Caralluma tuberculata in streptozotocin-induced diabetic rats

The current study aimed at evaluating the potential and mechanisms of the antidiabetic activity of the methanolic extract (ME) of Caralluma tuberculata as well as its chloroform (CF), n-butanol (BF) and the remaining water fractions (RFs) in streptozotocin-induced diabetic rats. The antidiabetic activity was evaluated through assessing fasting blood glucose (FBG), insulin levels, oral glucose tolerance test (OGTT), glucose utilization by isolated rat psoas muscle, gut glucose absorption and G-6-Pase activity in isolated rat liver microsomes. Both ME and RF showed the highest potency, where ME had superior activity. The mechanism underlying the observed antihyperglycemic activity of ME could be attributed, at least in part, to enhanced skeletal muscle utilization of glucose, inhibition of hepatic gluconeogenesis and stimulation of insulin secretion. ME was standardized through LC–MS analysis for its major pregnanes.     

葛根素对糖尿病大鼠主动脉糖基化终产物的形成及其受体表达的影响

目的　观察葛根素 (Puerarin ,Pue)对糖尿病 (DM)大鼠主动脉糖基化终产物 (AGEs)的形成及其受体 (RAGEmRNA)表达的影响。方法　以STZ诱导DM大鼠模型 ,并将DM大鼠随机分为DM对照组 (DM)、不同剂量葛根素治疗组 (0 5、0 2 5、0 1 2 5g·kg-1 ,ig )和氨基胍治疗组 (0 1g·kg-1 ,ig) ,另设一正常对照组 ,给药 1 2wk后 ,分别以葡萄糖氧化酶法测定血糖 ,NBT法测定血清果糖胺的含量 ,采用荧光法、RT PCR方法分别对主动脉AGEs的沉积及RAGEmRNA的表达进行检测。结果　Pue治疗后DM大鼠血糖、血清果糖胺含量明显降低 ,主动脉AGEs的形成量也明显低于DM模型组 (P <0 0 1 ) ,其治疗作用与氨基胍 (AG)相当 ;RAGE主要在内皮细胞表达 ,其表达量与AGEs的沉积量呈明显正相关 ,而葛根素也可明显下调RAGEmRNA在DM大鼠主动脉中的表达 (P<0 0 1 )。结论　葛根素可通过有效降低糖尿病大鼠血糖、血清果糖胺的含量 ,减少主动脉AGEs的沉积 ,下调主动脉中RAGEmRNA的表达 ,即通过抑制糖尿病大鼠主动脉非酶糖化的形成来防治DM血管病变的发生发展     

葛根素对糖尿病大鼠心肌糖基化终产物受体mRNA表达的影响

目的探讨葛根素对链脲佐菌素(STZ)诱导的糖尿病大鼠心肌糖化终产物受体(RAGE)mRNA逆转录水平的影响。方法雄性SD大鼠30只,随机分为三组:正常对照组(C组),糖尿病组(D组),糖尿病葛根素治疗组(DP组),用STZ一次性腹腔注射建立糖尿病模型后,DP组每天给予葛根素腹腔注射100mg/(kg·d),C组、D组每天给予同等剂量的生理盐水腹腔注射。每隔2周称体质量、测量血糖一次。8周后麻醉取下腔静脉血测定血清心肌酶(CK-MB),并取心肌组织行半定量RT-PCR检测RAGE mRNA表达水平的变化。结果成模8周时糖尿病大鼠与正常组相比体质量、血糖差异有统计学意义(P<0.01),DP组与D组间的血糖差异有统计学意义(P<0.05),体质量差异无统计学意义(P>0.05);DP组、D组和C组各组间RAGE表达差异有统计学意义(P<0.01);DP组与D组相比血清CK-MB下降,差异有统计学意义(P<0.05)。结论糖尿病大鼠心肌RAGE mRNA表达明显高于正常对照组。葛根素能下调糖尿病大鼠心肌RAGE在mRNA水平的表达,降低糖尿病大鼠CK-MB水平,减轻对心肌细胞的损害,对心脏具有保护作用。     

晚期糖基化终末产物及受体在实验性2型糖尿病大鼠种植体周围的变化及表达

目的建立2型糖尿病大鼠动物模型,探讨晚期糖基化终末产物及其受体在实验性2型糖尿病大鼠种植体骨整合过程中的变化及表达。方法 45只3个月龄SD健康雄性大鼠,将大鼠随机分为糖尿病模型组25只和正常对照组20只。首先建立2型糖尿病大鼠模型,建模成功后将模型大鼠随机分为DM组和DM种植组,每组10只。将20只正常组大鼠随机分为正常对照组和正常种植组,每组10只。分别于正常种植组和DM种植组的胫骨近骺端植入纯钛种植体,植入10周后于下腔静脉采血,保存所采集标本,用RF-5301PC型荧光分光光度计测定血清中AGEs含量的变化。硬组织标本采用不带种植体脱钙切片,以正常组为对照,HE染色后用免疫组织化学方法检测种植体周围RAGE的表达。结果 10周后,DM种植组和DM组与正常对照组和正常种植组相比,血清中AGEs的变化差异有统计学意义(P<0.05),正常种植组和DM种植组与正常对照组的种植体周围骨组织RAGE表达比较,差异均有统计学意义(P<0.05);DM种植组与DM组比较,差异亦有统计学意义(P<0.05)。结论种植体骨组织愈合过程中AGEs和RAGE相互作用是影响2型糖尿病种植体骨结合的机制之一。     

Nephroprotective effect of Paeonia emodi via inhibition of advanced glycation end products and oxidative stress in streptozotocin–nicotinamide induced diabetic nephropathy

The present study aimed to evaluate the effect of alcohol (PA) and hydroalcohol (PHA) extract of Paeonia emodi Royale roots in treatment of streptozotocin–nicotinamide induced diabetic nephropathy. Diabetes mellitus was induced in male Wistar rats by streptozotocin (65 mg/kg intraperitoneally) 15 minutes after nicotinamide (230 mg/kg, intraperitoneally) administration and diabetic nephropathy was assessed by measuring serum glucose, renal parameters (urea, uric acid, creatinine, and blood urea nitrogen level) and lipid profile. The rats were treated with different doses of extracts (100 mg/kg, 200 mg/kg, and 400 mg/kg) for 45 days. Oxidative stress was assessed by measuring tissue antioxidant enzymes level along with the formation of advanced glycation end-products (AGEs) in kidney. PA and PHA (400 mg/kg) produced significant attenuation in the serum glucose level (165.08 ± 3.353 mg/dL and 154.27 ± 2.209 mg/dL, respectively) as compared to control. Elevated renal parameters, lipid levels, tissue antioxidant enzymes and AGE formation were also restored in a dose-dependent manner. These findings suggest that by amelioration of oxidative stress and formation of AGEs, PA and PHA significantly inhibited the progression diabetic nephropathy in rats.     

皮肤晚期糖基化终末产物与2型糖尿病周围神经病变的相关性研究

目的 分析2型糖尿病(T2DM)伴周围神经病变(DPN)患者皮肤晚期糖基化终末产物(AGEs)水平变化及其临床意义.方法 选择99例T2DM患者,依据神经缺陷评分(NDS)将其分为DPN组和非DPN组,同时选取正常对照组(NC组)35例,测定各组皮肤AGEs和糖化血红蛋白(HbA1c)水平并进行比较.结果 与NC组相比,T2DM患者皮肤AGEs水平明显升高(P<0.05);与非DPN组相比,DPN组患者皮肤AGEs水平明显增(P<0.05),两组HbA1c水平差异无统计学意义(P>0.05).结论 T2DM患者皮肤AGEs水平升高可能参与糖尿病周围神经病变的发生.     

Therapeutic effect of green tea extract on advanced glycation and cross-linking of collagen in the aorta of streptozotocin diabetic rats

1. The therapeutic effect of green tea extract (GTE) on the aortic collagen content and its characteristics were investigated in streptozotocin diabetic rats. 2. Diabetes was induced in rats by a single intra peritoneal injection of streptozotocin (60 mg/kg bodyweight). Six weeks after diabetes induction, GTE was administered orally for four weeks (300 mg/kg bodyweight daily). Systolic blood pressure, blood glucose, anti-oxidant status, collagen content, extent of glycation, collagen linked fluorescence and aortic collagen solubility pattern were determined in experimental rats. 3. At the end of the experimental period, there was a significant increase in the systolic blood pressure and blood glucose in diabetic rats. The lipid peroxides increased whereas glutathione and vitamin C levels were decreased in the serum of diabetic rats. The collagen content, extent of glycation, the advanced glycation end products (AGEs) and degree of cross-linking were increased in the aorta of diabetic rats. 4. The oral administration of GTE to diabetic rats significantly reduced the systolic blood pressure and blood glucose. The level of lipid peroxides reduced and the content of glutathione and vitamin C increased in the serum of GTE treated diabetic rats. Green tea extract also impede the accumulation of aortic collagen, extent of glycation, formation of AGEs and cross-linking of collagen in diabetic rats. The antihyperglycemic, anti-oxidant and antiglycating effects of GTE ascribed for these beneficial effects. In conclusion, green tea may have therapeutic effect in the treatment of cardiovascular complications characterized by increased AGE accumulation and protein cross-linking associated with diabetes.     

Selective inhibition by grape seed proanthocyanidin extracts of cell adhesion molecule expression induced by advanced glycation end products in endothelial cells

The interaction of advanced glycation end products (AGE) with their cell surface receptors for AGEs (RAGE) has been causally implicated in the pathogenesis of diabetic vascular complications and has been shown to stimulate cell adhesion molecule expression in endothelial cells via induction of reactive oxygen species (ROS). Alternatively, grape seed proanthocyanidin extracts (GSPE), which are naturally occurring polyphenolic compounds, have been reported to possess potent radical scavenging and antioxidant properties and to display significant cardiovascular protective action. In this study, we investigated whether GSPE could inhibit AGE-induced cell adhesion molecule expression through interference with ROS generations in human umbilical vein endothelial cells. AGE-modified bovine serum albumin (AGE-BSA) was prepared by incubating BSA with a high concentration of glucose. Stimulation of cultured human umbilical vein endothelial cells with 200 microg/mL of AGE-BSA significantly enhanced intracellular ROS formation and subsequently upregulated the expression of vascular cell adhesion molecule-1 (VCAM) and intercellular adhesion molecule-1 (ICAM-1), whereas both unmodified BSA and GSPE alone were without effect. However, preincubation of different concentrations of GSPE markedly downregulated AGE-BSA-induced VCAM-1 expression at the surface protein and mRNA level in a concentration-dependent manner, but the increased ICAM-1 expression was not affected by GSPE treatment. Meanwhile, the inhibition by GSPE of intracellular ROS generation was also observed at defined time periods. These results demonstrate that GSPE can inhibit the enhanced VCAM-1 expression but not ICAM-1 in AGE-exposed endothelial cells by suppressing ROS generation. Hence, GSPE may have therapeutic potential in the prevention and treatment of vascular complications in patients with diabetes.