scholarly journals Protective Effects ofPanax notoginsengSaponins against High Glucose-Induced Oxidative Injury in Rat Retinal Capillary Endothelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yue Fan ◽  
Yuan Qiao ◽  
Jianmei Huang ◽  
Minke Tang

Diabetic retinopathy, a leading cause of visual loss and blindness, is characterized by microvascular dysfunction. Hyperglycemia is considered the major pathogenic factor for diabetic retinopathy and is associated with increased oxidative stress in the retina. In this study, we investigated the potential protective effects ofPanax notoginsengSaponins (PNS) in retinal capillary endothelial cells (RCECs) exposed to high glucose conditions. We found a pronounced increase in cell viability in rat RCECs incubated with both PNS and high glucose (30 mM) for 48 h or 72 h. The increased viability was accompanied by reduced intracellular hydrogen peroxide (H2O2) and superoxide (O2-), decreased mitochondrial reactive oxygen species (ROS), and lowered malondialdehyde (MDA) levels. PNS also increased the activities of total superoxide dismutase (SOD), MnSOD, catalase (CAT), and glutathione peroxidase (GSH-PX). The glutathione (GSH) content also increased after PNS treatment. Furthermore, PNS reduced NADPH oxidase 4 (Nox4) expression. These results indicate that PNS exerts a protective effect against high glucose-induced injury in RCECs, which may be partially attributed to its antioxidative function.

2015 ◽  
Vol 35 (1) ◽  
pp. 364-373 ◽  
Author(s):  
Preeti Kanikarla-Marie ◽  
Sushil K. Jain

Background/Aims: The incidence of developing microvascular dysfunction is significantly higher in type 1 diabetic (T1D) patients. Hyperketonemia (acetoacetate, β-hydroxybutyrate) is frequently found along with hyperglycemia in T1D. Whether hyperketonemia per se contributes to the excess oxidative stress and cellular injury observed in T1D is not known. Methods: HUVEC were treated with ketones in the presence or absence of high glucose for 24 h. NOX4 siRNA was used to specifically knockdown NOX4 expression in HUVEC. Results: Ketones alone or in combination with high glucose treatment cause a significant increase in oxidative stress, ICAM-1, and monocyte adhesivity to HUVEC. Using an antisense approach, we show that ketone induced increases in ROS, ICAM-1 expression, and monocyte adhesion in endothelial cells were prevented in NOX4 knockdown cells. Conclusion: This study reports that elevated levels of ketones upregulate NOX, contributing to increased oxidative stress, ICAM-1 levels, and cellular dysfunction. This provides a novel biochemical mechanism that elucidates the role of hyperketonemia in the excess cellular injury in T1D. New drugs targeting inhibition of NOX seems promising in preventing higher risk of complications associated with T1D.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Wuyang Huang ◽  
Zheng Yan ◽  
Dajing Li ◽  
Yanhong Ma ◽  
Jianzhong Zhou ◽  
...  

Blueberries possess abundant anthocyanins, which benefit eye health. The purpose of this study was to explore the protective functional role of blueberry anthocyanin extract (BAE) and its predominant constituents, malvidin (Mv), malvidin-3-glucoside (Mv-3-glc), and malvidin-3-galactoside (Mv-3-gal), on high glucose- (HG-) induced injury in human retinal capillary endothelial cells (HRCECs). The results showed that BAE, Mv, Mv-3-glc, and Mv-3-gal enhanced cell viability (P<0.05 versus the HG group at 24 h); decreased the reactive oxygen species (ROS, P<0.01 versus the HG group both at 24 and 48 h); and increased the enzyme activity of catalase (CAT) and superoxide dismutase (SOD) (P<0.05 versus the HG group both at 24 and 48 h). Mv could greatly inhibit HG-induced Nox4 expression both at 24 and 48 h (P<0.05), while BAE and Mv-3-gal downregulated Nox4 only at 48 h (P<0.05). Mv, Mv-3-glc, and Mv-3-gal also changed nitric oxide (NO) levels (P<0.05). BAE and Mv-3-glc also influenced angiogenesis by decreasing the vascular endothelial cell growth factor (VEGF) level and inhibiting Akt pathway (P<0.05). Moreover, Mv and Mv-3-glc inhibited HG-induced intercellular adhesion molecule-1 (ICAM-1, P<0.001) and nuclear factor-kappa B (NF-κB) (P<0.05). It indicated that blueberry anthocyanins protected HRCECs via antioxidant and anti-inflammatory mechanisms, which could be promising molecules for the development of nutraceuticals to prevent diabetic retinopathy.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Li ◽  
Songping Yu ◽  
Jia Ying ◽  
Tianyan Shi ◽  
Peipei Wang

Resveratrol (RSV) is used as a protective therapy against diabetic retinopathy. However, the mechanism(s) underlying this protective effect has not been fully elucidated. Bovine retinal capillary endothelial cells (BRECs), an in vitro model, were used to investigate the mechanism of RSV. Our results showed that high glucose induced significant cellular apoptosis in BRECs, which was accompanied by increased intracellular levels of reactive oxygen species (ROS) and cleaved caspase-3. The glucose-induced apoptosis and ROS elevation were both inhibited by RSV. High glucose was found to decrease the levels of phosphorylated AMP-activated protein kinase (p-AMPK), which was accompanied by increased levels of Sirt1 and PGC-1α. These changes were reversed by RSV. We also demonstrated that AMPK regulates the modulations of Sirt1 and PGC-1α using specific inhibitors of AMPK and Sirt1 and small interfering RNAs of PGC-1α. In summary, the current study demonstrates that RSV is effective against high glucose-induced cellular apoptosis and its action is exerted via the inhibition of ROS/AMPK/Sirt1/PGC-1α pathway.


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