Hanna Pawluk

Melatonin improves oxidative stress parameters measured in the blood of elderly type 2 diabetic patients.

Abstract:  An elevated oxidative status in the aging organism may be involved in the development of non‐insulin dependent diabetes mellitus (NIDDM). Melatonin, a potent antioxidant agent, is essential for glucose homeostasis and regulation. The aim of this study was to determine the influence of melatonin supplementation on the oxidative stress parameters in elderly NIDDM patients. The malondialdehyde (MDA) concentration, Cu‐Zn superoxide dismutase (SOD‐1) activity in erythrocytes, the level of nitrate/nitrite in plasma and morning melatonin concentration and oxidase activity of ceruloplasmin (Cp) in serum in 15 elderly NIDDM patients at baseline and after the 30 days of melatonin supplementation (5 mg daily) in comparison with levels in 15 healthy elderly volunteers were determined. A significant increase of MDA level and decrease of SOD‐1 activity and melatonin concentration were observed in NIDDM patients. Cp oxidase activity and nitrate/nitrite level were similar in both examined groups. Melatonin administration in NIDDM patients resulted in a significant increase in the morning melatonin concentration and SOD‐1 activity, and a reduction in the MDA level and Cp oxidase activity. Statistically significant alterations in nitrate/nitrite levels were not observed. These results indicate an improvement of antioxidative defense after melatonin supplementation in the NIDDM individuals and suggest melatonin supplementation as an additional treatment for the control of diabetic complications.

Antioxidative effects of melatonin administration in elderly primary essential hypertension patients

Abstract:  The imbalance of the redox state of the aging organism may be involved in the development of primary essential hypertension. Melatonin, a potent antioxidant agent, was found to exert a hypotensive effect and improve the function of the cardiovascular system. The aim of this study was to determine the influence of melatonin supplementation on oxidative stress parameters in elderly primary essential hypertensive (EH) patients, controlled by a diuretic (indapamide) monotherapy. The levels of malondialdehyde (MDA) and reduced glutathione (GSH), activities of Cu–Zn superoxide dismutase (SOD‐1), catalase (CAT) and glutathione peroxidase (GSH‐Px) in erythrocytes, the plasma level of nitrate/nitrite, the content of carbonyl groups of plasma proteins and morning melatonin levels in the serum of 17 elderly EH patients were determined at the baseline and after the 15th and 30th days of melatonin supplementation (5 mg daily). Melatonin administration resulted in a significant increase in the morning melatonin concentration, SOD‐1 and CAT activities, and a reduction in the MDA level. Statistically significant alterations in the levels of GSH, nitrate/nitrite and carbonyl groups and the activity of GSH‐Px were not observed. These results indicate an improvement in the antioxidative defense of the organism by melatonin supplementation in the examined group and may suggest melatonin supplementation as an additional treatment supporting hypotensive therapy in elderly EH patients.

Effect of melatonin on the oxidative stress in erythrocytes of healthy young and elderly subjects

Abstract:  The disturbances in pro‐ and antioxidant balance may play an important role in the pathomechanism of aging. The pineal hormone melatonin, which exerts effective antioxidative properties, is suggested to be involved in the aging process. The aim of this study was to compare the oxidative stress in erythrocytes of healthy young adults and elderly people, and to determine the influence of melatonin supplementation on measured parameters in both examined groups. The malondialdehyde (MDA) and reduced glutathione levels as well as Cu‐Zn superoxide dismutase (SOD‐1), catalase, glutathione peroxidase (GSH‐Px), glutathione S‐transferase (GST) and glutathione reductase (GR) activities in erythrocytes and morning serum melatonin concentration in 14 healthy young adults and 14 healthy elderly people at baseline and after the 30th day of melatonin (5 mg daily) supplementation were determined. A significant age effect on increasing the MDA level and decreasing SOD‐1, GSH‐Px and GR activities as well as melatonin concentration was observed. Melatonin supplementation resulted in a significant increase in melatonin concentration, SOD‐1 and GR activities and a decrease in the MDA level in both examined groups. These data indicate an age‐related augmentation of oxidative stress in erythrocytes and the improvement of erythrocytic antioxidative defense by melatonin administration. These results might suggest melatonin supplementation to prevent age‐related diseases and to prolong the lifespan and improve the quality of life of elderly people.

Age-related changes in an antioxidant defense system in elderly patients with essential hypertension compared with healthy controls

Abstract Background and aims Oxidative stress has been reported to increase with aging. Oxidative stress is also associated with hypertension, and antioxidant treatment has been shown to enhance antioxidant defense system. We therefore aimed to analyze the relationship between aging and some markers of oxidative stress in elderly patients with essential hypertension compared with healthy controls. Material and Methods Blood was collected from 18 patients with essential hypertension and 21 age- and sex-matched healthy controls aged over 65. Patients were on their usual medications while participating in the study. Oxidative stress parameters were investigated by measuring the concentration of glutathione (GSH) in whole blood and activities of glutathione peroxidase (GPx-1), glutathione reductase (GR), catalase (CAT), and Cu–Zn superoxide dismutase (CuZn SOD, SOD-1) in erythrocytes. GSH, GPx-1, GR, CAT, and CuZn SOD correlations with age were expressed as Pearson product-moment correlation coefficient r. Independent-samples T test was used to compare mean values of parameters between groups. Results (1) Among all parameters analyzed herein, the activity of SOD-1 showed the most explicit decrease in relation to age, both in healthy controls and hypertensive subjects with r values of −0.54 (P = 0.05) and −0.68 (P < 0.01), respectively. (2) Age-related changes in parameters of oxidative stress did not differ significantly between groups. (3) Mean activity of SOD-1 was significantly higher (P < 0.05) in elderly hypertensives (2341.7 ± 213.71 U/g Hb) when compared with healthy controls (2199.7 ± 213.66 U/g Hb). (4) Mean GSH level was significantly higher (P < 0.01) in patients (3.1 ± 0.29 mmol/l) than in controls (2.8 ± 0.37 mmol/l). (5) Increased level of GSH in hypertension was followed by significantly (P < 0.01) higher activity of GR in this group when compared with controls (83.4 ± 15.25 and 64.1 ± 9.40 U/g Hb, respectively). Conclusions (1) The antioxidant barrier changes in elderly subjects with senescence. (2) CuZn SOD activity is negatively correlated with age and this association is not altered by factors that modulate the enzyme activity, such as hypertension and antihypertensive treatment. (3) Significantly higher concentration of GSH and significantly higher GR activity in patients may suggest a significant role of GSH metabolism in the pathogenesis of hypertension, as well as its contribution to the effect of antihypertensive treatment.

Effects of coenzyme Q10 supplementation on activities of selected antioxidative enzymes and lipid peroxidation in hypertensive patients treated with indapamide. A pilot study

Introduction An increase in oxidative stress is strongly documented in hypertensive patients. In blood vessels, oxidative stress increases the production of superoxide anion (O2•−) that reacts with nitric oxide (NO) and impairs the ability of endothelium to relax. Many reports indicate a beneficial effect of coenzyme Q10 (CoQ) in hypertension. Coenzyme Q10 therapy may lower O2•− and thus decrease the complications associated with hypertension. The aim of our study was to evaluate the effects of CoQ supplementation on antioxidative enzyme activities and lipid peroxidation in elderly hypertensive patients. Material and methods We determined the activities of superoxide dismutase (SOD-1) and glutathione peroxidase (GSH-Px) and the concentration of malondialdehyde (MDA) in erythrocytes of 27 elderly (mean age 72.5 ±6.1 year) hypertensive patients treated with indapamide at baseline and after 12 weeks of CoQ supplementation (60 mg twice a day) in comparison with 30 healthy elderly volunteers (mean age 76.8 ±8.5 year). Results Decrease of SOD-1 (p < 0.001) and insignificant reduction of GSH-Px activities and increase of MDA (p < 0.001) level were observed in hypertensive patients in comparison to healthy volunteers before supplementation. Coenzyme Q10 administration resulted in a significant increase only in SOD-1 activity (p < 0.001). Conclusions The present study indicates that CoQ improves the most important component of the antioxidant defence system – SOD-1, which is responsible for O2•− scavenging. Coenzyme Q10 may be used as an additional therapeutic agent for prophylaxis and treatment of hypertension in elderly patients.

Effects of perindopril and hydrochlorothiazide on selected indices of oxidative stress in the blood of elderly patients with essential hypertension.

1 The aim of the present study was to determine the effect of hypotensive therapy with a diuretic (hydrochlorothiazide) and an angiotensin‐converting enzyme inhibitor (perindopril) on selected oxidative stress parameters in the blood of elderly patients with essential hypertension. 2 Studies were performed in 45 elderly patients with essential hypertension at baseline and after the 45th day of perindopril (n = 25) or hydrochlorothiazide (n = 20) therapy, as well as in 25 young and 25 elderly normotensive subjects. The following parameters were measured: systolic and diastolic blood pressure, nitric oxide (NO), carbonyl groups and malondialdehyde (MDA) concentrations, as well as the activity of ceruloplasmin (Cp) oxidase, Cu‐Zn superoxide dismutase (SOD‐1) and catalase (CAT). 3 The activity of SOD‐1 and NO levels were reduced with age. 4 Compared with elderly controls, hypertensive subjects showed increases in baseline MDA, carbonyl group concentrations and Cp oxidase activity and decreases in NO levels and SOD‐1 and CAT activities. 5 Treatment with perindopril, but not hydrochlorothiazide, resulted in significant increases in SOD‐1 and CAT activities and decreases in MDA concentration and Cp oxidase activity. Both therapies decreased the level of carbonyl groups and increased NO levels. 6 Angiotensin‐converting enzyme inhibitor therapy has significant anti‐oxidant effects that may be important in the treatment of elderly patients with essential hypertension.

Production of nitric oxide, lipid peroxidation and oxidase activity of ceruloplasmin in blood of elderly patients with primary hypertension. Effects of perindopril treatment

Background and aims: One of the factors playing a role in both the aging process and the etiopathogenesis of primary hypertension is oxidative stress. The purpose of this work was to estimate the production of nitric oxide (NO), oxidase activity of ceruloplasmin (Cp) and level of malondialdehyde (MDA), the end-product of lipid peroxidation in the blood of elderly patients with primary hypertension. The influence of treatment with the angiotensin-con-verting enzyme inhibitor perindopril (P) on the above parameters was also ascertained. Methods: The study was carried out on 37 patients (69–91 yrs) with primary hypertension, treated with perindopril for 6 weeks, and normotensive subjects who constituted the two control groups: 25 (65–96 yrs — K1)and 23 (22–41 yrs — K2). Cp oxidase activity in serum, MDA level expressed as the concentration of substances reacting to thiobarbituric acid in red blood cells, and production of NO (concentration of nitrite/nitrate in plasma) by the Griess reaction were all determined. Results: In the group of patients with hypertension, Cp activity was significantly higher than that in the control groups (K1 and K2). MDA concentrations in the erythrocytes of patients with hypertension were significantly higher than in the control groups and hypertensive patients had a lower NO (nitrite/nitrate) levels in plasma when compared with controls. In patients with hypertension, after only 7 days of therapy a substantial decrease in Cp oxidative activity was found, although the lowest value was observed after 6 weeks of therapy. Nevertheless, significantly lower MDA was observed after 6 weeks of therapy, corresponding to the values obtained in controls (K1 and K2). After 6 weeks of perindopril therapy, NO (nitrite/nitrate) was statistically higher in comparison with the values obtained before therapy. Conclusions: Results confirm intensification of oxidative stress and disorders in the production of NO in elderly patients with primary hypertension, and indicate the beneficial antioxidant effect of P.

Biomarkers of antioxidant status and lipid peroxidation in elderly patients with hypertension

ABSTRACT Objective: The objective of the present study was to examine selected parameters of the blood redox system in elderly patients with hypertension.examine selected parameters of the blood redox system in elderly patients with hypertension. Methods: We analyzed differences in redox-associated molecules and enzymes among elderly hypertensive subjects (age above 65 years, n = 49) and two groups of normotensive subjects (<65 years old – Control group I; n = 27, and >65 – Control group II; n = 30). Results: Decreased activity of antioxidant enzymes, increased lipid peroxidation and reduced production of nitric oxide were observed in hypertensive subjects, compared to healthy younger controls, or those of the same age. In healthy controls, an age-related decrease in the production of nitric oxide and the activities of SOD-1 and GPx-1 was also evident. The pathology of hypertension was characterised by further, significant decreases in the values of these parameters. When the subgroups of females and males were compared to their respective controls, a compromised redox balance was observed that was more evident in female hypertensives. Discussion: Hypertension in elderly patients is accompanied by changes in biomarkers of antioxidant status and lipid peroxidation status, which significantly differ from those observed in healthy ageing subjects. Our study also suggests that the relationship of gender and changes in redox balance with regard to hypertension should be further explored.