scholarly journals Does the Glucose-Dependent Insulin Secretion Mechanism Itself Cause Oxidative Stress in Pancreatic  -Cells?

Diabetes ◽  
2004 ◽  
Vol 53 (8) ◽  
pp. 1942-1948 ◽  
Author(s):  
L. E. Fridlyand ◽  
L. H. Philipson
Author(s):  
WannJun Gan ◽  
OanhhHoang Do ◽  
Louise Cottle ◽  
Elena Kosobrodova ◽  
Justin CooperrWhite ◽  
...  

2018 ◽  
Vol 51 (1) ◽  
pp. 201-216 ◽  
Author(s):  
Arwa M.T. Al-Nahdi ◽  
Annie John ◽  
Haider  Raza

Background/Aims: Numerous studies have reported overproduction of reactive oxygen species (ROS) and alterations in mitochondrial energy metabolism in the development of diabetes and its complications. The potential protective effects of N-acetylcysteine (NAC) in diabetes have been reported in many therapeutic studies. NAC has been shown to reduce oxidative stress and enhance redox potential in tissues protecting them against oxidative stress associated complications in diabetes. In the current study, we aimed to investigate the molecular mechanisms of the protective action of NAC on STZ-induced toxicity in insulin secreting Rin-5F pancreatic β-cells. Methods: Rin-5F cells were grown to 80% confluence and then treated with 10mM STZ for 24h in the presence or absence of 10mM NAC. After sub-cellular fractionation, oxidative stress, GSH-dependent metabolism and mitochondrial respiratory functions were studied using spectrophotometric, flow cytometric and Western blotting techniques. Results: Our results showed that STZ-induced oxidative stress and apoptosis caused inhibition in insulin secretion while NAC treatment restored the redox homeostasis, enhanced insulin secretion in control cells and prevented apoptosis in STZ-treated cells. Moreover, NAC attenuated the inhibition of mitochondrial functions induced by STZ through partial recovery of the mitochondrial enzymes and restoration of membrane potential. STZ-induced DNA damage and expression of apoptotic proteins were significantly inhibited in NAC-treated cells. Conclusion: Our results suggest that the cytoprotective action of NAC is mediated via suppression of oxidative stress and apoptosis and restoration of GSH homeostasis and mitochondrial bioenergetics. This study may, thus, help in better understanding the cellular defense mechanisms of pancreatic β-cells against STZ-induced cytotoxicity.


2015 ◽  
Vol 18 (1) ◽  
pp. 72-77
Author(s):  
Shaheda Zannah ◽  
Monirul Islam ◽  
Yusuf Ali ◽  
Md Asaduzzaman ◽  
Md Shahid Sarwar ◽  
...  

Hyperglycemia exerts toxic effects on the pancreatic ?-cells. This study investigated the hypothesis that the antidiabetic drugs glibenclamide and metformin, in combination with hydroxychloroquine (HCQ) offer additional protection for the pancreas against oxidative stress and produce hepatoprotective effect in alloxan-induced diabetic rats. Diabetes was induced in male Long-Evans rats by a single dose of alloxan (120 mg/kg; i.p.). Different groups of diabetic animals were treated with glibenclamide (10 mg/70 kg, i.p.), metformin (850 mg/70 kg, i.p.), HCQ (300 mg/70 kg, i.p.) and combination of both glibenclamide and metformin with HCQ, separately for a period of 28 days. Diabetic rats had significantly elevated levels of serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT), while catalase (CAT) and superoxide dismutase (SOD) activity were significantly reduced. Glibenclamide and metformin produced no significant effects on antioxidant enzymes but both showed significant (p<0.05) result in reducing SGOT and SGPT level in diabetic rats. In contrast, the combination of glibenclamide or metformin with HCQ showed better effect on up-regulation of CAT and SOD activity and down-regulation of SGOT and SGPT activity in comparison with the antidiabetic drug alone. These findings suggest that, HCQ potentiates the effect of glibenclamide and metformin to protect pancreas against oxidative stress and produce hepatoprotective effect in diabetic rats.Bangladesh Pharmaceutical Journal 18(1): 72-77, 2015


Diabetes ◽  
2005 ◽  
Vol 55 (1) ◽  
pp. 193-201 ◽  
Author(s):  
J. Yang ◽  
R. K. Wong ◽  
M. Park ◽  
J. Wu ◽  
J. R. Cook ◽  
...  

2018 ◽  
Vol 37 (12) ◽  
pp. 1268-1281 ◽  
Author(s):  
A Ahangarpour ◽  
S Alboghobeish ◽  
AA Oroojan ◽  
MA Dehghani

The growing use of carbon nanotubes (CNTs) emphasizes the importance of its potential toxic effects on the human health. Previous studies proved that CNTs caused oxidative stress and decreased cell viability. On the other hand, reactive oxygen species (ROS) and oxidative stress impaired β-cell functions and reduced the insulin secretion. However, there is not any study on the effects of CNTs on islets and β-cells. Therefore, the present study aimed to evaluate the effects of single-walled CNTs (SWCNTs) on oxidative stress in islets in addition to the protective effects of naringin (NRG) as an antioxidant . We examined the effects of SWCNTs and naringin on islets by 3,4 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay; measurement of insulin secretion, ROS, and malondialdehyde (MDA); activities of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) peroxidase (GSH-Px); and content of GSH and mitochondrial membrane potential (MMP). The MTT assay demonstrated that decreased viability of islets cells was dose-dependent with exposure to SWCNTs. Further studies revealed that SWCNTs decreased insulin secretion and MMP, induced the formation of ROS, increased the level of MDA, and decreased the activities of SOD, GSH-Px, and CAT and content of GSH. Furthermore, the pretreatment of islets with naringin significantly reverted back these changes. These findings revealed that SWCNTs might induce the oxidative stress to pancreatic islets, causing the occurrence of diabetes, and the protective effects of naringin that was mediated by augmentation of the antioxidant defense system of islets. Our research indicated the necessity for further in vivo and in vitro researches on the effects of SWCNTs and naringin on diabetes.


Sign in / Sign up

Export Citation Format

Share Document