• Nutrition Research and Practice
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• v.11 no.5
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• pp.430-434
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• 2017

BACKGROUND/OBJECTIVE: Chronic 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/METHODS: Human 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. RESULTS: Hyperglycemic 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. CONCLUSIONS: The results of our study supports current researches that state fisetin and luteolin as potential agents for the development of novel strategies for diabetes.

• International Journal of Oral Biology
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• v.49 no.2
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• pp.27-33
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• 2024

Diabetes, a chronic hyperglycemic condition, is caused by insufficient insulin secretion or functional impairment. Long-term inadequate regulation of blood glucose levels or hyperglycemia can lead to various complications, such as retinopathy, nephropathy, and cardiovascular disease. Recent studies have explored the molecular mechanisms linking diabetes to bone loss and an increased susceptibility to fractures. This study reviews the characteristics and molecular mechanisms of diabetes-induced bone disease. Depending on the type of diabetes, changes in bone tissue vary. The molecular mechanisms responsible for bone loss in diabetes include the accumulation of advanced glycation end products (AGEs), upregulation of inflammatory cytokines, induction of oxidative stress, and deficiencies in insulin/IGF-1. In diabetes, alveolar bone loss results from complex interactions involving oral bacterial infections, host responses, and hyperglycemic stress in periodontal tissues. Therapeutic strategies for diabetes-induced bone loss may include blocking the AGEs signaling pathway, decreasing inflammatory cytokine activity, inhibiting reactive oxygen species generation and activity, and controlling glucose levels; however, further research is warranted.

• Korean Journal of Pharmacognosy
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• v.27 no.1
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• pp.65-74
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• 1996

The studies were conducted to investigate the anti-diabetic activities on the hyperglycemia induced by streptozotocin in rats, Anti-fatigue, Decrease of body weight activities in mouse and anti-gastric ulcer activities in stress-induced rats by Mixed Extracts of Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex in Korea. 1. The blood glucose levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(100, 200, 400, significantly 200+100mg/kg) of Mixed Extracts from Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex. 2. The serum total cholesterol levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses (100, 200, 400, significantly 200+100mg/kg) of Mixed Extracts from Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex. 3. The serum triglyceride levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(100, 200, 400, significantly 200+100mg/kg) of Mixed Extracts from Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex. 4. The swimming time levels in mouse were dose-dependently extended by administrations of various doses(100, 200, 400, significantly 200+100mg/kg) of Mixed Extracts from Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex. 5. The body weight levels in mouse were dose-dependently decreased by administrations of various doses(100, 200, 400, significantly 200+100mg/kg) of Mixed Extracts from Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex. 6. Stress-induced gastric ulcer were dose-dependently repaired by administrations of various doses(100, 200, 400, significantly 200+100mg/kg) of Mixed Extracts from Acantopanacis senticosi Radicis Cortex and Eucommiae Cortex.

• Journal of Life Science
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• v.33 no.11
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• pp.851-858
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• 2023

Unique cartilage matrix-associated protein (UCMA) is an extrahepatic vitamin K-dependent protein rich in γ-carboxylated (Gla) residues. UCMA has been recognized for its ability to promote osteoblast differentiation and enhance bone formation; however, its impact on osteoblasts under hyperglycemic stress remains unknown. In this paper, we investigated the effect of UCMA on MC3T3-E1 osteoblastic cells under hyperglycemic conditions. After exposure to high glucose, the MC3T3-E1 cells were treated with recombinant UCMA proteins. CellROX and MitoSOX staining showed that the production of reactive oxygen species (ROS), which initially increased under high-glucose conditions in MC3T3-E1 cells, decreased after UCMA treatment. Additionally, quantitative polymerase chain reaction revealed increased expression of antioxidant genes, nuclear factor erythroid 2-related factor 2 and superoxide dismutase 1, in the MC3T3-E1 cells exposed to both high glucose and UCMA. UCMA treatment downregulated the expression of heme oxygenase-1, which reduced its translocation from the cytosol to the nucleus. Moreover, the expression of dynamin-related protein 1, a mitochondrial fission marker, was upregulated, and AKT signaling was inhibited after UCMA treatment. Overall, UCMA appears to mitigate ROS production, increase antioxidant gene expression, impact mitochondrial dynamics, and modulate AKT signaling in osteoblasts exposed to high-glucose conditions. This study advances our understanding of the cellular mechanism of UCMA and suggests its potential use as a novel therapeutic agent for bone complications related to metabolic disorders.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.175-180
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• 2009

Taurine is the most abundant free amino acid in the retina and transported into retina via taurine transporter (TauT) at the inner blood-retinal barrier (iBRB). In the present study, we investigated whether the taurine transport at the iBRB is regulated by oxidative stress or disease-like state in a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB) used as an in vitro model of iBRB. First, [$^3H$]taurine uptake and efflux by TR-iBRB were regulated in the presence of extracellular $Ca^{2+}$. [$^3H$]Taurine uptake was inhibited and efflux was enhanced under $Ca^{2+}$ free condition in the cells. In addition, oxidative stress inducing agents such as tumor necrosis factor-$\alpha$ (TNF-$\alpha$), lipopolysaccharide (LPS), diethyl maleate (DEM) and glutamate increased [$^3H$]taurine uptake and decreased [$^3H$]taurine efflux in TR-iBRB cells. Whereas, 3-morpholinosydnonimine (SIN-1), which is known to NO donor decreased [$^3H$]taurine uptake. Lastly, TR-iBRB cells exposed to high glucose (25 mM) medium and the [$^3H$]taurine uptake was reduced about 20% at the condition. Also, [$^3H$]taurine uptake was decreased by cytochalasin B, which is known to glucose transport inhibitor. In conclusion, taurine transport in TR-iBRB cells is regulated diversely at extracellular $Ca^{2+}$, oxidative stress and hyperglycemic condition. It suggested that taurine would play a role as a retinal protector in diverse disease states.

• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.474-480
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• 2008

Purpose : Stress hyperglycemia is common in critically ill adult patients. It is known as a predictor of increased mortality, and intensive insulin therapy has been shown to improve the prognosis in such patients. We have investigated the relationship between early stress hyperglycemia and clinical outcomes in preterm infants. Methods : In this study, 141 preterm infants with a gestational age of less than 30 weeks were enrolled. The hyperglycemic group was defined as that having maximum glucose of more than 150 mg/dL (n=61) during the first 48 h of life, and the non-hyperglycemic group was defined as that having maximum glucose of less than 150 mg/dL (n=80). Perinatal history, severity of illness using the Clinical Risk Index for Babies (CRIB) score, clinical outcomes, and mortality of the two groups were compared. Results : There was no significant difference in the gestational age between the two groups, but the birth weight (P<0.001) was significantly lower, and the CRIB score (P<0.001) was significantly higher in the hyperglycemic group. Disseminated intravascular coagulation (P<0.001) and clinically suspected sepsis (P=0.046) were more common in the hyperglycemic group. Mortality was markedly higher in the hyperglycemic group (11.3% vs. 41.0%, P<0.001). On performing a stepwise multiple logistic regression analysis, hyperglycemia (OR 3.787; 95% CI 1.324 to 10.829), the CRIB score (OR 1.252; 95% CI 1.047 to 1.496) and birth weight (OR 0.997; 95% CI 0.994 to 1.000) was independently associated with higher mortality. Conclusion : Stress hyperglycemia within the first 48 h of life is independently related to increased morbidity and mortality in preterm infants.

• Natural Product Sciences
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• v.15 no.3
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• pp.167-172
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• 2009

The protective effects of Phaleria macrocarpa (PM) against oxidative stress in diabetic rats were investigated. Diabetes was induced in male Sprague Dawley rats using alloxan (150 mg/kg i.p). After the administration of PM fractions for two weeks the diabetic symptoms, nephropathy and renal antioxidant enzymes were evaluated. The results showed that the oral PM treatments reduced blood glucose levels in diabetic rats. The PM fractions decreased kidney hypertrophy and diminished blood urea nitrogen (BUN) in diabetic rats. Malondialdehyde (MDA), a lipid peroxidation marker, was increased in diabetic animals, but was suppressed by the PM treatments. In addition, the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, and glutathione (GSH) level in the alloxan-induced diabetic rats were significantly decreased compared with those in the normal rats, but were restored by PM treatments. The PM fractions also suppressed the level of MDA in the kidney. In conclusion, the anti hyperglycemic and anti-nephropathy of P. macrocarpa may be correlated to the increased renal antioxidant enzyme activity in the kidney.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.20-26
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• 2014

Obesity is an epidemic disease characterized by an increased inflammatory state and chronic oxidative stress with high levels of pro-inflammatory cytokines and lipid peroxidation. Moreover, obesity alters cholesterol metabolism with increases in low-density lipoprotein (LDL) cholesterols and triglycerides and decreases in high-density lipoprotein (HDL) cholesterols. It has been shown that mulberry leaf and fruit ameliorated hyperglycemic and hyperlipidemic conditions in obese and diabetic subjects. We hypothesized that supplementation with mulberry leaf combined with mulberry fruit (MLFE) ameliorate cholesterol transfer proteins accompanied by reduction of oxidative stress in the high fat diet induced obesity. Mice were fed control diet (CON) or high fat diet (HF) for 9 weeks. After obesity was induced, the mice were administered either the HF or the HF with combination of equal amount of mulberry leaf and fruit extract (MLFE) at 500mg/kg/day by gavage for 12 weeks. MLFE treatment ameliorated HF induced oxidative stress demonstrated by 4-hydroxynonenal (4-HNE) and modulated the expression of 2 key proteins involved in cholesterol transfer such as scavenger receptor class B type 1 (SR-B1) and ATP-binding cassette transporter A1 (ABCA1) in the HF treated animals. This effect was mainly noted in liver tissue rather than in cutaneous tissue. Collectively, this study demonstrated that MLFE treatment has beneficial effects on the modulation of high fat diet-induced oxidative stress and on the regulation of cholesterol transporters. These results suggest that MLFE might be a beneficial substance for conventional therapies to treat obesity and its complications.

• Natural Product Sciences
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• v.15 no.1
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• pp.37-43
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• 2009

Oxidative stress is caused by an imbalance between the production of reactive oxygen and an ability of a biological system, to readily detoxify the reactive intermediates or easily repair the resulting damage. It has been suggested that developmental alloxan-induced liver damage is mediated through increases in oxidative stress. The anti-diabetic effect and antioxidant activity of Phaleria macrocarpa (PM) fractions were investigated in alloxan-induced diabetic rats. After two weeks administration of PM, the liver antioxidant enzyme and hyperglycemic state were evaluated. The results showed that oral administration of PM treatments reduced blood glucose levels in diabetic rats by oral administration (P < 0.05). Serum glutamic-oxaloacetic transaminase (sGOT) and serum glutamic-pyruvate-transaminase (sGPT) were also diminished by PM supplementation. The superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPx) activities, and glutathione (GSH) level in the alloxan-induced diabetic rats were significantly decreased (P < 0.05) compared to those in the normal rats but were restored by PM treatments. PM fractions also repressed the level of malondialdehyde (MDA) in the liver. Glutathione reductase (GR), glutathione-S-transferase (GST) and $\gamma$-glutamylcysteine synthase (GCS) were also reduced in alloxan-induced diabetic rats. PM fractions could restore the GR and GST activities, but the GCS activity was not affected in rat livers. From the results of the present study, the diabetic effect of the butanol fraction of PM against alloxan-induced diabetic rats was concluded to be mediated either by preventing the decline of hepatic antioxidant status or due to its indirect radical scavenging capacity.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.668-675
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• 2017

To assess the physiological effects of Aruncus dioicus var. kamtschaticus extract on cytoxicity of a neuronal cell line, antioxidant activity, and neuroprotection against intensive glucose-induced oxidative stress were quantitated. Compared to the other fractions, the ethyl acetate fraction of Aruncus dioicus var. kamtschaticus (EFAD) showed the highest total phenolics and flavonoids. The 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay and malondialdehyde inhibitory effect test confirmed the superior antioxidant activity of EFAD. Moreover, EFAD also decreased the intracellular ROS level and suppressed neuronal cell death against intensive glucose- or $H_2O_2$-induced oxidative stress. Additionally, assessment of ${\alpha}$-glucosidase and acetylcholinesterase inhibitory activities revealed that EFAD was an effective inhibitor of ${\alpha}$-glucosidase and acetylcholinesterase. Finally, high-performance liquid chromatography analysis identified caffeic acid as the main ingredient of EFAD. Overall, these results suggest that the EFAD is a good natural source of biological compounds that counteract hyperglycemic neuronal defects.