High Glucose-induced Oxidative Stress Research Articles

Spirulina platensis prevents high glucose-induced oxidative stress mitochondrial damage mediated apoptosis in cardiomyoblasts.

The current study was undertaken to study the effect of Spirulina platensis (Spirulina) extract on enhanced oxidative stress during high glucose induced cell death in H9c2 cells. H9c2 cultured under high glucose (33mM) conditions resulted in a noteworthy increase in oxidative stress (free radical species) accompanied by loss of mitochondrial membrane potential, release of cytochrome c, increase in caspase activity and pro-apoptotic protein (Bax). Spirulina extract (1μg/mL), considerably inhibited increased ROS and RNS levels, reduction in cytochrome c release, raise in mitochondrial membrane potential, decreased the over expression of proapoptotic protein Bax and suppressed the Bax/Bcl2 ratio with induced apoptosis without affecting cell viability. Overall results suggest that Spirulina extract plays preventing role against enhanced oxidative stress during high glucose induced apoptosis in cardiomyoblasts as well as related dysfunction in H9c2 cells.

P 205 - Effects of metabolites derived from Hibiscus sabdariffa on high glucose-induced oxidative stress and inflammation in hypertrophied 3T3-L1 adipocytes

Recent evidences indicate that polyphenols from Hibiscus sabdariffa L. (HS) may become an alternative against metabolic disturbances associated to obesity. Our findings strongly support that quercetin derivatives from HS are absorbed and metabolized in vivo and suggests that these metabolites are the major blood compounds accounting for these effects. The purpose of this work was to determine the effect of several quercetin derivatives (quercetin, quercetin-3-glucuronide and quercetin-3-glucoside) compared with others of recognized capacity to reduce oxidative stress and inflammation in a high-glucose hypertrophied adipocyte model. The results indicate that HS and quercetin derivatives reduce glucolipotoxicity-induced oxidative stress in 3T3-L1 adipocytes and INS832/13 β-cells. Furthermore, among all the polyphenolic compounds tested, quercetin derivatives were the more active compounds reducing ROS generation in hypertrophied 3T3-L1 adipocytes. These flavonoids also modulated pro-inflammatory adipokine secretion and reduced the expression of MCP-1 cytokine at transcriptional level in the hypertrophied cell model. In conclusion, these data suggest that quercetin derivatives seem to be the main responsible compounds of the antioxidant and anti-inflammatory activities of HS extract.

Relationship of angiotensin I-converting enzyme (ACE) and bradykinin B2 receptor (BDKRB2) polymorphism with diabetic nephropathy

PurposeTo determine whether ACE22ACE: angiotensin-converting enzyme I/D and BDKRB233BDKRB2: bradykinin B2 receptor +9/−9 polymorphism causatively affect diabetic nephropathy progression ResultsSTZ-induced metabolic disorder, as well as inflammatory responses, was significantly aggravated in ACE II-B2R44B2R: B2 receptor+9bp, ACE DD-B2R+9bp, or ACE DD-B2R−9bp diabetic mice but not ACE II-B2R−9bp, indicating the genetic susceptibility of ACE DD or B2R+9bp to diabetic nephropathy. Furthermore, ACE II-B2R+9bp, ACE DD-B2R+9bp, or ACE DD-B2R−9bp rather than ACE II-B2R−9bp, worsened renal performance and enhanced pathological alterations induced by STZ. Markedly elevated monocyte chemoattractant protein-1(MCP-1), podocin, osteopontin (OPN), transforming growth factor-β1 (TGF-β1), and reduced nephrin, podocin were also detected both in diabetic mice and podocytes under hyperglycemic conditions in response to ACE II-B2R+9bp, ACE DD-B2R+9bp, or ACE DD-B2R−9bp, versus ACE II-B2R−9bp. In addition, high glucose-induced mitochondrial oxidative stress and cell apoptosis were observably increased in response to ACE II-B2R+9bp, ACE DD-B2R+9bp, or ACE DD-B2R−9bp but not ACE II-B2R−9bp. ConclusionsWe provide first evidence indicating the causation between ACE DD or B2R+9bp genotype and the increased risk for diabetic nephropathy, broadening our horizon about the role of genetic modulators in this disease.

Hydrogen sulfide inhibits high glucose-induced NADPH oxidase 4 expression and matrix increase by recruiting inducible nitric oxide synthase in kidney proximal tubular epithelial cells

High-glucose increases NADPH oxidase 4 (NOX4) expression, reactive oxygen species generation, and matrix protein synthesis by inhibiting AMP-activated protein kinase (AMPK) in renal cells. Because hydrogen sulfide (H2S) inhibits high glucose-induced matrix protein increase by activating AMPK in renal cells, we examined whether H2S inhibits high glucose-induced expression of NOX4 and matrix protein and whether H2S and NO pathways are integrated. High glucose increased NOX4 expression and activity at 24 h in renal proximal tubular epithelial cells, which was inhibited by sodium hydrosulfide (NaHS), a source of H2S. High glucose decreased AMPK phosphorylation and activity, which was restored by NaHS. Compound C, an AMPK inhibitor, prevented NaHS inhibition of high glucose-induced NOX4 expression. NaHS inhibition of high glucose-induced NOX4 expression was abrogated by N(ω)-nitro-l-arginine methyl ester, an inhibitor of NOS. NaHS unexpectedly augmented the expression of inducible NOS (iNOS) but not endothelial NOS. iNOS siRNA and 1400W, a selective iNOS inhibitor, abolished the ameliorative effects of NaHS on high glucose-induced NOX4 expression, reactive oxygen species generation, and, matrix laminin expression. Thus, H2S recruits iNOS to generate NO to inhibit high glucose-induced NOX4 expression, oxidative stress, and matrix protein accumulation in renal epithelial cells; the two gasotransmitters H2S and NO and their interaction may serve as therapeutic targets in diabetic kidney disease.

Protective effect of CDDO-ethyl amide against high-glucose-induced oxidative injury via the Nrf2/HO-1 pathway

Background ContextIntervertebral disc degeneration (IDD) is the main cause of low back pain, and nucleus pulposus (NP) cell apoptosis is an important risk factor of IDD. However, the molecular mechanism of this disease remains unknown. PurposeTo assess the potential protective effect of CDDO-ethyl amide (EA) against high-glucose-induced oxidative stress injury in NP cells and to investigate the mechanism of antioxidative effects and apoptotic inhibition. Study Design/SettingTo find new molecule to inhibit intervertebral disc degeneration. MethodsViability, reactive oxygen species (ROS) levels, and apoptosis were examined in NP cells. The protein expression levels of HO-1 and Nrf2 were measured through Western blot ResultsCDDO-EA elicited cytoprotective effects against NP cell apoptosis and ROS accumulation induced by high glucose. CDDO-EA treatment increased the HO-1 and Nrf2 expression abrogated by HO-1, Nrf2, and mitogen-activated protein kinase inhibitors. ConclusionsThe phosphorylation and nuclear translocation of Nrf2 are crucial for HO-1 overexpression induced by CDDO-EA, which is essential for the cytoprotection against high–glucose-induced oxidative stress in NP cells.

Luteolin and fisetin suppress oxidative stress by modulating sirtuins and forkhead box O3a expression under in vitro diabetic conditions.

BACKGROUND/OBJECTIVEChronic hyperglycemia induces oxidative stress via accumulation of reactive oxygen species (ROS) and contributes to diabetic complications. Hyperglycemia induces mitochondrial superoxide anion production through the increased activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. This study aimed to determine whether fisetin and luteolin treatments suppress the oxidative stress by modulating the expression of sirtuins (SIRTs) and forkhead box O3a (FOXO3a) under hyperglycemic conditions in human monocytes.MATERIALS/METHODSHuman monocytic cells (THP-1) were cultured under osmotic control (14.5 mmol/L mannitol), normoglycemic (NG, 5.5 mmol/L glucose), or hyperglycemic (HG, 20 mmol/L glucose) conditions, in the absence or presence of fisetin and luteolin for 48 h. To determine the effect of fisetin and luteolin treatments on high glucose-induced oxidative stress, western blotting and intracellular staining were performed.RESULTSHyperglycemic conditions increased the ROS production, as compared to normoglycemic condition. However, fisetin and luteolin treatments inhibited ROS production under hyperglycemia. To obtain further insight into ROS production in hyperglycemic conditions, evaluation of p47phox expression revealed that fisetin and luteolin treatments inhibited p47phox expression under hyperglycemic conditions. Conversely, the expression levels of SIRT1, SIRT3, SIRT6, and FOXO3a were decreased under high glucose conditions compared to normal glucose conditions, but exposure to fisetin and luteolin induced the expression of SIRT1, SIRT3, SIRT6, and FOXO3a. The above findings suggest that fisetin and luteolin inhibited high glucose-induced ROS production in monocytes through the activation of SIRTs and FOXO3a.CONCLUSIONSThe results of our study supports current researches that state fisetin and luteolin as potential agents for the development of novel strategies for diabetes.

Effect of ALDH2 on High Glucose-Induced Cardiac Fibroblast Oxidative Stress, Apoptosis, and Fibrosis.

Our study aimed firstly to observe whether ALDH2 was expressed in neonate rat cardiac fibroblasts, then to investigate the effect of activation of ALDH2 on oxidative stress, apoptosis, and fibrosis when cardiac fibroblasts were subjected to high glucose intervention. Cultured cardiac fibroblasts were randomly divided into normal (NG), NG + Alda-1, high glucose (HG), HG + Alda-1, HG + Alda-1 + daidzin, HG + daidzin, and hypertonic groups. Double-label immunofluorescence staining, RT-PCR, and Western blot revealed ALDH2 was expressed in cardiac fibroblasts. Compared with NG, ALDH2 activity and protein expression were reduced, and cardiac fibroblast proliferation, ROS releasing, 4-HNE protein expression, collagen type I and III at mRNA levels, and the apoptosis rate were increased in HG group. While in HG + Alda-1 group, with the increases of ALDH2 activity and protein expression, the cardiac fibroblast proliferation and ROS releasing were decreased, and 4-HNE protein expression, collagen type I and III at mRNA levels, and apoptosis rate were reduced compared with HG group. When treated with daidzin in HG + Alda-1 group, the protective effects were inhibited. Our findings suggested that ALDH2 is expressed in neonate rat cardiac fibroblasts; activation of ALDH2 decreases the HG-induced apoptosis and fibrosis through inhibition of oxidative stress.

Ellagic Acid Reduces High Glucose-Induced Vascular Oxidative Stress Through ERK1/2/NOX4 Signaling Pathway

Background/Aims: Elevated production of reactive oxygen species (ROS) is linked to endothelial dysfunction and is one of the key contributors to the pathogenesis of diabetic vascular complications. Emerging evidence has indicated that ellagic acid (EA), a polyphenol found in fruits and nuts, possesses numerous biological activities including radical scavenging. However, whether EA exerts a vasculo-protective effect via antioxidant mechanisms in blood vessels exposed to diabetic conditions remains unknown. Accordingly, the goal of this current study was to determine whether EA decreases vascular ROS production and thus ameliorates endothelial dysfunction in the diabetic milieu. Methods: Intact rat aortas and human aortic endothelial cells (HAEC) were stimulated with 30mM high glucose (HG) with and without EA co-treatment. Endothelium-dependent vasodilation was measured using a wire myograph. Gene and protein expression of non-phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 4 (NOX4) were detected using RT-PCR and western blotting, respectively. Oxidative stress was determined by measuring ROS levels using dihydroethidium (DHE) staining. Results: Intact aortas exposed to HG condition displayed exacerbated ROS production and impairment of endothelium-dependent vasodilation, characterizing endothelial dysfunction. These effects were markedly reduced with EA treatment. HG enhanced ROS production in HAEC, paralleled by increased ERK1/2 activation and NOX4 expression. EA treatment blunted the increase of ROS generation, ERK1/2 activation and decreased NOX4. Conclusions: EA significantly decreases endothelial ROS levels and ameliorates the impairment of vascular relaxation induced by HG. Our results suggest that EA exerts a vasculo-protective effect under diabetic conditions via an antioxidant effect that involves inhibition of ERK1/2 and downregulation of NOX4.

A novel antioxidant peptide derived from wheat germ prevents high glucose-induced oxidative stress in vascular smooth muscle cells in vitro.

The ingestion of whole wheat products is responsible for the prevention of a number of chronic diseases. The aim of this study is to characterize the molecular properties of a novel wheat germ-derived antioxidant peptide (AOP) in protection against high glucose-induced oxidative stress in vascular smooth muscle cells (VSMCs). AOP (amino acid sequence AREGETVVPG) was isolated from wheat germ albumin using dual-enzymatic hydrolysis/separation, followed by MS/MS. The in vitro IC50 value for Fe2+ chelation was 0.77 mM. The stability of purified AOP was confirmed by hydrolyzation in a simulated gastrointestinal (GI) digestion system in vitro. Furthermore, AOP significantly prevented high glucose-induced cell growth by 37.4 ± 2.7%, decreased the generation of intracellular reactive oxygen species (ROS) by 22.3 ± 4.6%, suppressed the phosphorylation of PKCζ, AKT and Erk1/2, and inhibited Nox4 protein expression. Our findings suggested that AOP exerted a protective role against high glucose-induced oxidative stress through the inhibition of the PKCζ/Nox4 signaling pathway in VSMCs.

1,4-Anhydro-4-seleno-d-talitol (SeTal) protects endothelial function in the mouse aorta by scavenging superoxide radicals under conditions of acute oxidative stress

Hyperglycaemia increases the generation of reactive oxidants in blood vessels and is a major cause of endothelial dysfunction. A water-soluble selenium-containing sugar (1,4-Anhydro-4-seleno-d-talitol, SeTal) has potent antioxidant activity in vitro and is a promising treatment to accelerate wound healing in diabetic mice. One possible mechanism of SeTal action is a direct effect on blood vessels. Therefore, we tested the hypothesis that SeTal prevents endothelial dysfunction by scavenging reactive oxidants in isolated mouse aorta under conditions of acute oxidative stress induced by hyperglycaemia. Aortae were isolated from C57BL/6 male mice and mounted on a wire-myograph to assess vascular function. In the presence of a superoxide radical generator, pyrogallol, 300μM and 1mM of SeTal effectively prevented endothelial dysfunction compared to other selenium-containing compounds. In a second set of ex vivo experiments, mouse aortae were incubated for three days with either normal or high glucose, and co-incubated with SeTal at 37°C in 5% CO2. High glucose significantly reduced the sensitivity to the endothelium-dependent agonist, acetylcholine (ACh), increased superoxide production and decreased basal nitric oxide (NO) availability. SeTal (1mM) co-treatment prevented high glucose-induced endothelial dysfunction and oxidative stress in the mouse aorta. The presence of a cyclooxygenase inhibitor, indomethacin significantly improved the sensitivity to ACh in high glucose-treated aortae, but had no effect in SeTal-treated aortae. Our data show that SeTal has potent antioxidant activity in isolated mouse aortae and prevents high glucose-induced endothelial dysfunction by decreasing superoxide levels, increasing basal NO availability and normalising the contribution of vasoconstrictor prostanoids.

Asiaticoside protects cochlear hair cells from high glucose-induced oxidative stress via suppressing AGEs/RAGE/NF-κB pathway.

Asiaticoside (AC) has been known to have anti-oxidative activity, however, the effect of AC on the progression of high glucose-induced hearing loss has not been studied. This study aims to analyze the effect of AC on cochlear hair cells under the treatment of high glucose in vitro and the hearing function in vivo. The results of MTT showed that high glucose decreased the activity of HEI-OC1 cells, but AC increased the activity of HEI-OC1 cells compared with high glucose group. The results of flow cytometry showed that AC decreased the degree of apoptosis induced by high levels of glucose. The results of DCFH-DA staining showed that AC inhibited the ROS production induced by high glucose levels. The results of JC-1 staining showed that AC inhibited the mitochondrial depolarization induced by high glucose levels. Furthermore, AC decreased the threshold, and protected inner and outer hair cells from damage in rats with hearing loss induced by diabetes mellitus. Moreover, AC decreased the activity of MDA, but, increased the activity of SOD, CAT and GSH-Px in vivo. AC also decreased the expression of AGEs, RAGE and NF-κB p65. Collectively, these results suggest that AC protects cochlear hair cells from high glucose-induced injury by increasing anti-oxidative activity and suppressing the AGEs/RAGE/NF-κB pathway.

Resveratrol ameliorates hyperglycemia-induced renal tubular oxidative stress damage via modulating the SIRT1/FOXO3a pathway.

Oxidative stress plays an important role in the development and progression of diabetic nephropathy (DN). We aimed to investigate if resveratrol (RSV) could ameliorate hyperglycemia-induced oxidative stress in renal tubules via modulating the SIRT1/FOXO3a pathway. The effects of RSV on diabetes rats were assessed by periodic acid-Schiff, Masson staining, immunohistochemistry, and western blot analyses. Additionally, oxidative indicators (such as catalase, superoxide dismutase, reactive oxygen species, and malondialdehyde), the deacetylase activity of SIRT1 and protein expressions of SIRT1, FOXO3a, and acetylated-FOXO3a were measured. These indicators were similarly evaluated in an in vitro study. Furthermore, the silencing of SIRT1 was used to confirm its role in the resistance to oxidative stress and the relationship between SIRT1 and FOXO3a in vitro. After 16weeks of RSV treatment, the renal function and glomerulosclerosis of rats with DN was dramatically ameliorated. RSV treatment increased SIRT1 deacetylase activity, subsequently decreasing the expression of acetylated-FOXO3a and inhibiting the oxidative stress caused by hyperglycemia both in vivo and in vitro. The silencing of SIRT1 in HK-2 cells aggravated the high glucose-induced oxidative stress and overexpression of acetylated-FOXO3a; RSV treatment failed to protect against these effects. RSV modulates the SIRT1/FOXO3a pathway by increasing SIRT1 deacetylase activity, subsequently ameliorating hyperglycemia-induced renal tubular oxidative stress damage. This mechanism provides the basis for a new approach to developing an effective DN treatment, which is of great clinical significance for reducing the morbidity and mortality associated with DN.

Ferro/Nubiola appoints FitzChem to sell in the mid-central United States

This study was designed to investigate the action of timosaponin B-II, a main bioactive compound in Anemarrhena asphodeloides Bunge, on the prevention from high glucose-induced cytotoxicity and apoptosis in human umbilical vein endothelial cells (HUVECs) and the potential mechanisms involved. The results showed that compared with the normal control group, exposure of HUVECs to high glucose media for 72 h resulted in a significant increase in lactates dehydrogenise release, reactive oxygen species production, Caspase-3 activity and the percentage of apoptotic cells (p < 0.01). However, pretreatment with timosaponin B-II significantly increased the viability of HUVECs and decreased lactates dehydrogenise release, Caspase-3 activity and the apoptosis rate in a concentration-dependent manner (p < 0.05). In addition, timosaponin B-II notably decreased the amount of reactive oxygen species and malondialdehyde, as well as promoted glutathione peroxidase activity, endothelial nitric oxide synthase activity and nitric oxide release (p < 0.05). These results suggest that timosaponin B-II has the antiapoptotic effect in endothelial cells through inhibition of high glucose-induced oxidative stress and has the potential for preventing diabetic cardiovascular complications.

Role of Sirtuin3 in high glucose-induced apoptosis in renal tubular epithelial cells

The apoptosis of renal tubular epithelial cells contributes to the pathogenesis of diabetic nephropathy. High glucose-induced mitochondrial oxidative stress is considered to be an important mediator for renal tubular cell apoptosis. Sirtuin3(Sirt3), a kind of mitochondria-localized nicotinamide adenine dinucleotide(NAD+)-dependent protein deacetylase, has been reported to regulate the generation of ROS in mitochondria through regulating acetylation level and activity of several key mitochondrial enzymes. In this study, we investigated the role of Sirt3 on high glucose-induced apoptosis in HK-2 cells. High glucose decreased the protein and mRNA expression of Sirt3 in a time-dependent manner, along with increased cell apoptosis in HK-2 cells. Furthermore, high glucose-induced oxidative stress and apoptosis were reversed by Sirt3 overexpression or antioxidant treatment. Meanwhile, we also found that overexpression of Sirt3 or antioxidant could regulate the activity of Akt/FoxO signaling pathway associated with cell apoptosis in diabetic nephropathy. In conclusion, our data suggest that Sirt3 overexpression antagonize high glucose-induced apoptosis by controlling ROS accumulation and ROS-sensitive Akt/FoxO signaling pathway in HK-2 cells.

Ameliorative effects of hispidulin on high glucose-mediated endothelial dysfunction via inhibition of PKCβII-associated NLRP3 inflammasome activation and NF-κB signaling in endothelial cells

Endothelial dysfunction is closely relevant to atherosclerosis complications in diabetic patients. Hispidulin, a flavone derived from the herb Salvia plebeia R. Br., has numerous biological properties including anti-inflammatory and antioxidative effects, but the underlying mechanism of its anti-inflammatory action remains unclear. This study was designed to investigate the effects of hispidulin on endothelial homeostasis and its mechanism. Hispidulin effectively inhibited high glucose-induced oxidative stress by attenuating PKCβII phosphorylation and downstream reactive oxygen species (ROS) production, furthermore reversing the loss of mitochondria membrane potential. Moreover, hispidulin significantly suppressed the expression of NLRP3 inflammasome and IKKβ/NF-κB, and restored high glucose-impaired vasodilation in rat aorta. This study demonstrated that hispidulin ameliorated high glucose-mediated endothelial dysfunction via inhibiting PKCβII-associated NLRP3 inflammasome activation and NF-κB signaling. Besides, these findings indicate the beneficial effects of hispidulin on the improvement of endothelial dysfunction and explain its potential application in the prevention and treatment of diabetic vascular complications.

GW27-e1151 ABCG1 protects vascular endothelial cells against high glucose-induced oxidative stress through the Nrf2-dependent pathway

ATP binding cassette transporter G1 (ABCG1), a regulator of cholesterol efflux to HDL, has been found its up-regulation reversed the high glucose-induced oxidative stress in endothelial cells in our previous study. The present study aimed to further implore whether the endogenous antioxidant gene

NADPH oxidase-2 does not contribute to β-cell glucotoxicity in cultured pancreatic islets from C57BL/6J mice

High glucose-induced oxidative stress and increased NADPH oxidase-2 (NOX2) activity may contribute to the progressive decline of the functional β-cell mass in type 2 diabetes. To test that hypothesis, we characterized, in islets from male NOX2 knockout (NOX2-KO) and wild-type (WT) C57BL/6J mice cultured for up to 3 weeks at 10 or 30 mmol/l glucose (G10 or G30), the in vitro effects of glucose on cytosolic oxidative stress using probes sensing glutathione oxidation (GRX1-roGFP2), thiol oxidation (roGFP1) or H2O2 (roGFP2-Orp1), on β-cell stimulus-secretion coupling events and on β-cell apoptosis.After 1–2 days of culture in G10, the glucose stimulation of insulin secretion (GSIS) was ∼1.7-fold higher in NOX2-KO vs. WT islets at 20–30 mmol/l glucose despite similar rises in NAD(P)H and intracellular calcium concentration ([Ca2+]i) and no differences in cytosolic GRX1-roGFP2 oxidation.After long-term culture at G10, roGFP1 and roGFP2-Orp1 oxidation and β-cell apoptosis remained low, and the glucose-induced rises in NAD(P)H, [Ca2+]i and GSIS were similarly preserved in both islet types. After prolonged culture at G30, roGFP1 and roGFP2-Orp1 oxidation increased in parallel with β-cell apoptosis, the glucose sensitivity of the NADPH, [Ca2+]i and insulin secretion responses increased, the maximal [Ca2+]i response decreased, but maximal GSIS was preserved. These responses were almost identical in both islet types.In conclusion, NOX2 is a negative regulator of maximal GSIS in C57BL/6J mouse islets, but it does not detectably contribute to the in vitro glucotoxic induction of cytosolic oxidative stress and alterations of β-cell survival and function.

Cinnamaldehyde attenuates high glucose-induced oxidative stress and endothelial dysfunction as an Nrf2 activator

Cinnamaldehyde attenuates high glucose-induced oxidative stress and endothelial dysfunction as an Nrf2 activator

The Nrf2 Activator Vinylsulfone Reduces High Glucose-Induced Neural Tube Defects by Suppressing Cellular Stress and Apoptosis.

The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is one of the primary pathways responsible for the cellular defense system against oxidative stress. Oxidative stress-induced apoptosis is a causal event in diabetic embryopathy. Thus, the Nrf2 pathway may play an important role in the induction of diabetic embryopathy. In the present study, we investigated the potentially protective effect of the Nrf2 activator, vinylsulfone, on high glucose-induced cellular stress, apoptosis, and neural tube defects (NTDs). Embryonic day 8.5 (E8.5) whole mouse embryos were cultured in normal (5 mmol/L) or high (16.7 mmol/L) glucose conditions, with or without vinylsulfone. At a concentration of 10 μmol/L, vinylsulfone had an inhibitory effect on high glucose-induced NTD formation, but it was not significant. At a concentration of 20 μmol/L, vinylsulfone significantly reduced high glucose-induced NTDs. In addition, 20 μmol/L vinylsulfone abrogated the high glucose-induced oxidative stress markers lipid hydroperoxide (LPO), 4-hydroxynonenal (4-HNE), and nitrotyrosine-modified proteins. The high glucose-induced endoplasmic reticulum (ER) stress biomarkers were also suppressed by 20 μmol/L vinylsulfone through the inhibition of phosphorylated protein kinase RNA-like ER kinase (PERK), inositol requiring protein 1α (IRE1a), eukaryotic initiation factor 2α (eIF2a), upregulated C/EBP-homologous protein (CHOP), binding immunoglobulin protein (BiP), and x-box binding protein 1 (XBP1) messenger RNA splicing. Furthermore, 20 μmol/L vinylsulfone abolished caspase 3 and caspase 8 cleavage, markers of apoptosis, in embryos cultured under high glucose conditions. The Nrf2 activator, vinylsulfone, is protective against high glucose-induced cellular stress, caspase activation, and subsequent NTD formation. Our data suggest that vinylsulfone supplementation is a potential therapy for diabetes-associated neurodevelopmental defects.

High Glucose로 유도된 산화 스트레스에 대한 황칠나무 잎 추출물의 뇌신경세포 보호 효과

Antioxidant activities and neuroprotective effects of ethyl acetate fraction from Dendropanax morbifera (EFDM) against high glucose-induced oxidative stress and neurotoxicity were investigated to confirm their physiological activities. An 80% ethanolic extract of D. morbifera showed the highest contents of total phenolic compounds as well as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. The extract was fractionated using several solvents, and the ethyl acetate fraction showed the highest activities in ferric reducing/antioxidant power and malondialdehyde inhibitory assays. To evaluate the neuroprotective effect based on antioxidant activities, cell viability was assessed using PC12 and MC-IXC cells in - and high glucose-induced cytotoxic assays, respectively. EFDM evidently showed neuroprotective effects in all cells (neuron-like PC12 cells and human brain-originated neuroblastoma MC-IXC cells). Inhibitory effect of the extract on acetylcholinesterase (AChE) as an acetylcholine-hydrolyzing enzyme was performed to examine the effect on cognitive function. EFDM presented an AChE inhibitory effect. Finally, high-performance liquid chromatography analysis showed that the major phenolic compound of EFDM is probably a rutin.