Effects of 17β-estradiol and antioxidant administration on oxidative stress and insulin resistance in ovariectomized rats

2011 ◽  
Vol 89 (7) ◽  
pp. 497-504 ◽  
Author(s):  
Amr M. Abbas ◽  
Ayman Z. Elsamanoudy

The prevalence of insulin resistance syndrome increases during menopause with the overproduction of reactive oxygen species and impairment of the free radical scavenger function. Therefore, we investigated the effects of 17β-estradiol (E2) and vitamin E, as an antioxidant, on lipid peroxidation and antioxidant levels in the brain cortex and liver of ovariectomized rats as well as on insulin resistance in those rats. Forty female Sprague–Dawley rats, 3 months of age and weighing 231.5 ± 9.4 g, were divided into 4 groups: sham, ovariectomized (OVX), OVX treated with E2 (40 µg/kg subcutaneously), and OVX treated with E2 and vitamin E (100 mg/kg intraperitoneally). The 4 groups received the appropriate treatment every day for 8 weeks. Levels of glutathione, glutathione peroxidase, superoxide dismutase , catalase, and malondialdehyde in the brain cortex and liver of ovariectomized rats were measured. Also, fasting plasma insulin, glucose, and homeostatis model assessment of insulin resistance (HOMA-IR) were determined. Malondialdehyde increased and antioxidants (glutathione, glutathione peroxidase, catalase, superoxide dismutase) decreased in the brain cortex and liver of OVX rats. Also, fasting glucose, insulin, and HOMA-IR increased in OVX rats. E2 and E2 plus vitamin E decreased malondialdehyde and increased antioxidants in the brain cortex and liver of OVX rats. Moreover, they decreased fasting glucose, insulin, and HOMA-IR in ovariectomized rats. This study demonstrates that E2 and E2 plus vitamin E supplementation to OVX rats may improve insulin resistance, strengthen the antioxidant system, and reduce lipid peroxidation.

2019 ◽  
Vol 97 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Lawrence A. Olatunji ◽  
Oluwaseun A. Adeyanju ◽  
Olugbenga S. Michael ◽  
Taofeek O. Usman ◽  
Rita C. Tostes ◽  
...  

Women have a lower incidence of cardiovascular diseases (CVD) than men at a similar age but the reverse is the case after menopause, indicating a possible protective effect of estrogen on cardiometabolic function. Although various hormonal therapies have been formulated to combat the CVD risks in postmenopausal state, the beneficial effects have not been consistent. Obesity with insulin resistance (IR) is closely linked to CVD risks while ovariectomized rodents have been shown to mimic a state of obesity and IR. We therefore hypothesized that low-dose spironolactone would ameliorate obesity and IR in estrogen-deprived rats by replenishing estrogen and suppressing elevated glycogen synthase kinase-3 (GSK-3). Ten-week-old female Wistar rats were divided into 4 groups: sham-operated (SHM), spironolactone (SPL; 0.25 mg/kg), and ovariectomized (OVX) rats treated with or without spironolactone daily for 8 weeks. Results showed that estrogen deprivation through ovariectomy caused increased body mass gain and visceral adiposity that are accompanied by increased HOMA-IR, HOMA-β, 1-hour postload glucose, glucose intolerance, platelet/lymphocyte ratio, plasma insulin, atherogenic dyslipidemia, uric acid, GSK-3, corticosterone, and aldosterone and depressed 17β-estradiol. However, treatment of OVX rats with spironolactone ameliorated all these effects. Taken together, the results demonstrate that treatment with low-dose spironolactone improves obesity and IR, which appears to involve replenishment of estrogen and suppression of GSK-3 along with circulating mineralocorticoid and glucocorticoid. The findings imply a positive cardiometabolic effect of low-dose spironolactone usage in estrogen-deprived conditions.


2016 ◽  
Vol 18 (2(66)) ◽  
pp. 52-59
Author(s):  
B.V. Gutyj ◽  
Y. Lavryshyn ◽  
V. Binkevych ◽  
O. Binkevych ◽  
О. Paladischuk ◽  
...  

The article contains the research results of the effect of cadmium chloride on the indexes of enzyme and nonenzyme systems of  antioxidant defense system in young cattle, such as the activity of catalase, superoxide dismutase, glutathione peroxidase, glutathione levels of vitamins A and E. It is established that feeding calves at a dose of toxicant 0.04 mg / kg activity of catalase, superoxide dismutase, glutathione peroxidase, glutathione levels of vitamins A and E in the blood of experimental animals decreased throughout the experiment. The lowest indicators of antioxidant in the blood of young cattle is set on the twenty -fourth day of the experiment, which is associated with increased activation of lipid peroxidation and the balance between antioxidant system and lipid peroxidation intensity. Given the cadmium load of young cattle it is used a new integrated drug with antioxidant action «Metisevit», which includes metifen, sodium selenite and vitamin E wich is founded as stimulating effects on the activity of antioxidant protection. In particular,it is established probable increase in activity of catalase, superoxide dismutase, glutathione peroxidase, glutathione levels, vitamin A and vitamin E in the blood of young cattle, which has performed cadmium stress. These changes occur through comprehensive action components of the drug «Metisevit» that leads to the normalization of metabolic processes and free radical in the body of the bull. The results of the research indicate antioxidant drug «Metisevit» in the application of its young cattle and the validity of his administration to improve the body's antioxidant status of chronic cadmium toxicosis.


2011 ◽  
Vol 301 (3) ◽  
pp. R676-R681 ◽  
Author(s):  
Cleyde V. Helena ◽  
Ruth Cristancho-Gordo ◽  
Arturo E. Gonzalez-Iglesias ◽  
Joël Tabak ◽  
Richard Bertram ◽  
...  

We have shown previously that an intravenous injection of oxytocin (OT) in ovariectomized (OVX) rats initiates a circadian rhythm of prolactin (PRL) secretion similar to that observed after cervical stimulation (CS). In this study, we investigated the pathway through which OT triggers the PRL rhythm. We first tested whether an intracerebroventricular injection of OT could trigger the PRL secretory rhythm. As it did not, we injected OT intravenously while an OT receptor antagonist was infused intravenously. This antagonist completely abolished the PRL surges, suggesting that a peripheral target of OT is necessary for triggering the PRL rhythm. We hypothesized that OT may induce PRL release, which would be transported into the brain and trigger the rhythm. In agreement with this, OT injection increased circulating PRL by 5 min. To test whether this acute increase in PRL release would induce the PRL rhythm, we compared the effect of intravenously administered thyrotropin-releasing hormone (TRH) and OT. Although TRH injection also increased PRL to a comparable level after 5 min, only OT-injected animals expressed the PRL secretory rhythm. Motivated by prior findings that bilateral resection of the pelvic nerve blocks CS-induced pseudopregnancy and OT-induced facilitation of lordosis, we then hypothesized that the OT signal may be transmitted through the pelvic nerve. In fact, OT injection failed to induce a PRL secretory rhythm in pelvic-neurectomized animals, suggesting that the integrity of the pelvic nerve is necessary for the systemic OT induction of the PRL secretory rhythm in OVX rats.


10.5219/1375 ◽  
2020 ◽  
Vol 14 ◽  
pp. 836-846
Author(s):  
Olena Shatynska ◽  
Oleksandr Tokarskyy ◽  
Petro Lykhatskyi ◽  
Olha Yaremchuk ◽  
Iryna Bandas ◽  
...  

The purpose of the current study was to evaluate the protective properties of dietary magnesium supplementation on pancreatic tissue of rats with alloxan-induced diabetes mellitus. Twenty-five male Wistar rats were split into five groups (control, diabetes, diabetes with 100 mg Mg daily, diabetes with 250 mg Mg daily, diabetes with 500 mg Mg daily) with feeding supplementation starting on day 1, diabetes induction on day 21, and animal sacrifice on day 30. Fasting glucose in blood serum was measured on days 21, 25, 27, and day 30. Glucose metabolism enzymes, namely, lactate dehydrogenase and glucose-6-phosphate dehydrogenase, were measured in pancreatic tissue upon the sacrifice, as well as lipid peroxidation, antioxidant system protective enzymes (catalase and superoxide dismutase), and glutathione system components (glutathione reductase, glutathione peroxidase, and glutathione reduced). Pearson correlation coefficients showed strong negative correlation between serum glucose (control and diabetic animals) and glucose metabolism enzymes, catalase, superoxide dismutase, glutathione peroxidase in pancreatic tissue (r >-0.9, p <0.05), moderate negative correlation with reduced glutathione (r = -0.79, p <0.05), moderate positive correlation with lipid peroxidation index (r = +0.67, p <0.05), weak correlation with glutathione reductase (r = -0.57, p <0.05). Magnesium supplementation slowed down diabetes onset considering fasting glucose levels in rats (p <0.05), as well as partially restored investigated dehydrogenase levels in the pancreas of rats comparing to diabetes group (p <0.05). The lipid peroxidation index varied between treatments showing the dose-dependent influence of Mg2+. Magnesium supplementation partially restored catalase and superoxide dismutase activities in pancreatic tissue, as well as glutathione peroxidase and reduced glutathione levels (p <0.05), while glutathione reductase levels remained unaffected (p >0.05). The obtained results suggested a model, where magnesium ions may have a possible protective effect on pancreatic tissue against the negative influence of alloxan inside β cells of the pancreas.


2016 ◽  
Vol 94 (9) ◽  
pp. 961-972 ◽  
Author(s):  
Ionut Caravan ◽  
Alexandra Sevastre Berghian ◽  
Remus Moldovan ◽  
Nicoleta Decea ◽  
Remus Orasan ◽  
...  

Menopause is accompanied by enhanced oxidative stress and behavioral changes, effects attenuated by antioxidants. The aim of this study was to evaluate the effects of caffeine on behavior and oxidative stress in an experimental model of menopause. Female rats were divided into the following groups: sham-operated (CON), sham-operated and caffeine-treated (CAF), ovariectomized (OVX), ovariectomized and caffeine-treated (OVX+CAF). Caffeine (6 mg/kg) and vehicle were administered for 21 days (subchronic) and 42 days (chronic), using 2 experimental subsets. Behavioral tests and oxidative stress parameters in the blood, whole brain, and hippocampus were assessed. The subchronic administration of caffeine decreased the lipid peroxidation and improved the antioxidant defense in the blood and brain. The GSH/GGSG ratio in the brain was improved by chronic administration, with reduced activities of antioxidant enzymes and enhanced nitric oxide and malondialdehyde levels. In particular, the lipid peroxidation in the hippocampus decreased in both experiments. The rats became hyperactive after 21 days of treatment, but no effect was observed after chronic administration. In both experimental subsets, caffeine had anxiolytic effects as tested in elevated plus maze. The administration of low doses of caffeine, for a short period of time, may be a new therapeutic approach to modulating the oxidative stress and anxiety in menopause.


2014 ◽  
Vol 12 (2) ◽  
pp. 43-46 ◽  
Author(s):  
Georgii Nolianovich Shilov ◽  
Vladislav Adamovich Ivanyutin

The antioxidant activity of some native catecholamines (adrenaline, noradrenaline, dopamine), water-soluble antioxidant emoxipine, agonist (apomorphine) and antagonist (haloperidol) of dopamine receptors was assessed as their influence on malonic dialdehyde content and products of lipid peroxidation in homogenates and suspension of the rat cortical brain cells. All catecholamines (adrenaline, noradrenaline, dopamine in concentrations of 10-4 M and 10-5 M) possessed a high (compartable with emoxipine) antioxidant activity. The most antioxidant effect was registered in apomorphine. The inhibitory action of apomorphine on lipid peroxidation in the brain cortex can be a result from both dopamine receptor activation and “direct” antioxidant mechanism.


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