Lipophilic Studies and In Silico ADME Profiling of Biologically Active 2-Aminothiazol-4(5H)-one Derivatives.

Pseudothiohydantoin derivatives have a wide range of biological activities and are widely used in the development of new pharmaceuticals. Lipophilicity is a basic, but very important parameter in the design of potential drugs, as it determines solubility in lipids, nonpolar solvents, and makes it possible to predict the ADME profile. The aim of this study was to evaluate the lipophilicity of 28 pseudothiohydantoin derivatives showing the inhibition of 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) using chromatographic methods. Experimentally, lipophilicity was determined by reverse phase thin layer chromatography (RP-TLC) and reverse phase high-performance liquid chromatography (RP-HPLC). In both methods, methanol was used as the organic modifier of the mobile phase. For each 2-aminothiazol-4(5H)-one derivative, a relationship was observed between the structure of the compound and the values of the lipophilicity parameters (log kw, RM0). Experimental lipophilicity values were compared with computer calculated partition coefficient (logP) values. A total of 27 of the 28 tested compounds had a lipophilicity value < 5, which therefore met the condition of Lipinski's rule. In addition, the in silico ADME assay showed favorable absorption, distribution, metabolism, and excretion parameters for most of the pseudothiohydantoin derivatives tested. The study of lipophilicity and the ADME analysis indicate that the tested compounds are good potential drug candidates.

A Review of Biologically Active Oxime Ethers.

Oxime ethers are a class of compounds containing the >C=N-O-R moiety. The presence of this moiety affects the biological activity of the compounds. In this review, the structures of oxime ethers with specific biological activity have been collected and presented, and bactericidal, fungicidal, antidepressant, anticancer and herbicidal activities, among others, are described. The review includes both those substances that are currently used as drugs (e.g., fluvoxamine, mayzent, ridogrel, oxiconazole), as well as non-drug structures for which various biological activity studies have been conducted. To the best of our knowledge, this is the first review of the biological activity of compounds containing such a moiety. The authors hope that this review will inspire scientists to take a greater interest in this group of compounds, as it constitutes an interesting research area.

Synthesis of Novel 2-(Cyclopentylamino)thiazol-4(5H)-one Derivatives with Potential Anticancer, Antioxidant, and 11ß-HSD Inhibitory Activities.

In this study, a series of nine new 2-(cyclopentylamino)thiazol-4(5H)-one derivatives were synthesized, and their anticancer, antioxidant, and 11ß-hydroxysteroid dehydrogenase (11ß-HSD) inhibitory activities were tested. Anticancer activity has been assessed using the MTS (MTS: 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay against human colon carcinoma (Caco-2), human pancreatic carcinoma (PANC-1), glioma (U-118 MG), human breast carcinoma (MDA-MB-231), and skin melanoma (SK-MEL-30) cancer cell lines. Cell viability reductions, especially in the case of Caco-2, MDA-MB-231, and SK-MEL-30 lines, were observed for most compounds. In addition, the redox status was investigated and oxidative, but nitrosative stress was not noted at a concentration of 500 µM compounds tested. At the same time, a low level of reduced glutathione was observed in all cell lines when treated with compound 3g (5-(4-bromophenyl)-2-(cyclopentylamino)thiazol-4(5H)-one) that most inhibited tumor cell proliferation. However, the most interesting results were obtained in the study of inhibitory activity towards two 11ß-HSD isoforms. Many compounds at a concentration of 10 µM showed significant inhibitory activity against 11ß-HSD1 (11ß-hydroxysteroid dehydrogenase type 1). The compound 3h (2-(cyclopentylamino)-1-thia-3-azaspiro[4.5]dec-2-en-4-one) showed the strongest 11ß-HSD1 inhibitory effect (IC50 = 0.07 µM) and was more selective than carbenoxolone. Therefore, it was selected as a candidate for further research.

11ß-Hydroxysteroid Dehydrogenase Type 1 as a Potential Treatment Target in Cardiovascular Diseases.

Glucocorticoids (GCs) belong to the group of steroid hormones. Their representative in humans is cortisol. GCs are involved in most physiological processes of the body and play a significant role in important biological processes, including reproduction, growth, immune responses, metabolism, maintenance of water and electrolyte balance, functioning of the central nervous system and the cardiovascular system. The availability of cortisol to the glucocorticoid receptor is locally controlled by the enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1). Evidence of changes in intracellular GC metabolism in the pathogenesis of obesity, metabolic syndrome (MetS) and cardiovascular complications highlights the role of selective 11ß-HSD1 inhibition in the pharmacotherapy of these diseases. This paper discusses the role of 11ß-HSD1 in MetS and its cardiovascular complications and the importance of selective inhibition of 11ß-HSD1.

11ß-HSD as a New Target in Pharmacotherapy of Metabolic Diseases.

Glucocorticoids (GCs), which are secreted by the adrenal cortex, are important regulators in the metabolism of carbohydrates, lipids, and proteins. For the proper functioning of the body, strict control of their release is necessary, as increased GCs levels may contribute to the development of obesity, type 2 diabetes mellitus, hypertension, cardiovascular diseases, and other pathological conditions contributing to the development of metabolic syndrome. 11ß-hydroxysteroid dehydrogenase type I (11ß-HSD1) locally controls the availability of the active glucocorticoid, namely cortisol and corticosterone, for the glucocorticoid receptor. Therefore, the participation of 11ß-HSD1 in the development of metabolic diseases makes both this enzyme and its inhibitors attractive targets in the pharmacotherapy of the above-mentioned diseases.

Assessment of the concentration of selected metalloproteinases (MMP-2, MMP-3, MMP-9 and MMP-13) in patients with ulcers as a complication of type 2 diabetes.

Introduction: Impaired chronic wound healing is a great challenge for modern medicine. This process causes ulceration especially in the course of diseases such as type II diabetes mellitus. Aim: This study assesses the concentration of selected matrix metalloproteinases in the example of metalloproteinase 2, 3, 9, 13 in patients with impaired healing of chronic wounds as a complication of type 2 diabetes. Material and methods: Nineteen people took part in the assessment of wound healing in patients with type 2 diabetes. The control group consisted of 21 healthy people. In the blood serum the concentration of MMP-2, MMP-3, MMP-9 and MMP-13 was determined. Results: The concentrations of MMP-2 and MMP-3 in the group of patients with ulcers were significantly higher (61% and 84% accordingly) compared to those in the control group without chronic wounds. No statistically significant differences in MMP-9 and MMP-13 concentrations were observed between the study and control groups. Conclusions: The increase in MMP-2 concentration, which is particularly active in the degradation of type IV collagen, which is the main component of the basal membranes, in patients with type 2 diabetes may impede and delay the healing of chronic wounds and thus contribute to the intensification of vascular complications. In turn, the increase in MMP-3 concentration, which plays a significant role in vascular diseases, in patients with type 2 diabetes may lead to intensification of atherosclerotic changes involving the arteries of the lower extremities and ulceration.

The Oxime Ethers with Heterocyclic, Alicyclic and Aromatic Moiety as Potential Anti-Cancer Agents.

Chemotherapy is one of the most commonly used methods of cancer disease treatment. Due to the acquisition of drug resistance and the possibility of cancer recurrence, there is an urgent need to search for new molecules that would be more effective in destroying cancer cells. In this study, 1-(benzofuran-2-yl)ethan-1-one oxime and 26 oxime ethers containing heterocyclic, alicyclic or aromatic moiety were screened for their cytotoxicity against HeLa cancer cell line. The most promising derivatives with potential antitumor activity were 2-(cyclohexylideneaminoxy)acetic acid (18) and (E)-acetophenone O-2-morpholinoethyl oxime (22), which reduced the viability of HeLa cells below 20% of control at concentrations of 100-250 µg/mL. Some oxime ethers, namely thiazole and benzothiophene derivatives (24-27), also reduced HeLa cell viability at similar concentrations but with lower efficiency. Further cytotoxicity evaluation confirmed the specific toxicity of (E)-acetophenone O-2-morpholinoethyl oxime (22) against A-549, Caco-2, and HeLa cancer cells, with an EC50 around 7 µg/mL (30 µM). The most potent and specific compound was (E)-1-(benzothiophene-2-yl)ethanone O-4-methoxybenzyl oxime (27), which was selective for Caco-2 (with EC50 116 µg/mL) and HeLa (with EC50 28 µg/mL) cells. Considering the bioavailability parameters, the tested derivatives meet the criteria for good absorption and permeation. The presented results allow us to conclude that oxime ethers deserve more scientific attention and further research on their chemotherapeutic activity.

Influence of Classical Massage on Biochemical Markers of Oxidative Stress in Humans: Pilot Study.

Classical massage is one of the most popular forms of conservative treatment in various diseases. Despite the wide scope of research, the mechanisms of massage are not fully known and understood. Apart from the well-described effects on individual body systems, there are few scientific reports on the effects of massage on the human body at the subcellular level. The study was designed to assess changes in oxidative stress parameters in healthy volunteers after a single session of classical massage. 29 healthy volunteers aged 22.24 ± 3.64 participated in the study. Before and 30 minutes after the massage procedures, blood samples were taken by experienced personnel. Biochemical markers of oxidative homeostasis were assessed with highly specific methods for each parameter: oxidase ceruloplasmin, glutathione, malondialdehyde, glutathione peroxidase, glutathione S-transferase, and superoxide dismutase. The study demonstrates that massage therapy caused statistically significant decrease in the concentration of glutathione peroxidase (red blood cells) and increase in the level of glutathione peroxidase (plasma), superoxide dismutase, and malondialdehyde. In contrast, statistically significant changes in the hematocrit, glutathione, NO2-/NO3-, and oxidase ceruloplasmin were not observed. The results show that complex influence of classical massage therapy on human organism may be reflected in parameters of the oxidative stress. To understand this mechanism clearly, further research is needed.

Concentration of proinflammatory cytokines in patients with ulcers as a complication of type 2 diabetes mellitus.

INTRODUCTION: Difficult healing of chronic wounds is a serious problem for modern medicine. It leads to ulceration, especially in conditions such as diabetic foot syndrome or chronic venous insufficiency. This may be a result of chemical, physical, thermal or biological factors, among others. Analysis of mediators and molecular factors released by the abovementioned structure helps to better understand the mechanism of healing of chronic wounds and the formation of ulcers. AIM: To assess excretion of selected cytokines in patients with ulcerations as a complication of diabetes mellitus type 2. MATERIAL AND METHODS: Seventeen patients aged 68-87 took part in the assessment of wound healing in patients with ulceration in the course of diabetes mellitus type 2. The control group consisted of 21 healthy patients aged 32-62. In the blood serum bFGF, TNF-α, IL-4, TGF-ß1, TGF-ß2 and TGF-ß3 were determined. RESULTS: A significant difference was found in bFGF, IL-4, TGF-ß1, TGF-ß2, and TGF-ß3 levels. Concentration of bFGF was 12% lower in patients with ulcers than in the non-ulcerated control group (p = 0.013). IL-4 concentration was 46% lower in patients with ulcers than in the non-ulcerated control group (p = 0.002). TGF-ß1, TGF-ß2 and TGF-ß3 concentrations were also lower in the group of patients with ulcers compared to those in the non-ulcerated control group. CONCLUSIONS: Reduced concentrations of selected cytokines and growth factors may indicate abnormal activity of the cells that secrete them and affect the healing process of chronic wounds, hindering and delaying the healing process.

Novel 2-(Adamantan-1-ylamino)Thiazol-4(5H)-One Derivatives and Their Inhibitory Activity towards 11ß-HSD1-Synthesis, Molecular Docking and In Vitro Studies.

A common mechanism in which glucocorticoids participate is suggested in the pathogenesis of such metabolic diseases as obesity, metabolic syndrome, or Cushing's syndrome. The enzyme involved in the control of the availability of cortisol, the active form of the glucocorticoid for the glucocorticoid receptor, is 11ß-HSD1. Inhibition of 11ß-HSD1 activity may bring beneficial results for the alleviation of the course of metabolic diseases such as metabolic syndrome, Cushing's syndrome or type 2 diabetes. In this work, we obtained 10 novel 2-(adamantan-1-ylamino)thiazol-4(5H)-one derivatives containing different substituents at C-5 of thiazole ring and tested their activity towards inhibition of two 11ß-HSD isoforms. For most of them, over 50% inhibition of 11ß-HSD1 and less than 45% inhibition of 11ß-HSD2 activity at the concentration of 10 µM was observed. The binding energies found during docking simulations for 11ß-HSD1 correctly reproduced the experimental IC50 values for analyzed compounds. The most active compound 2-(adamantan-1-ylamino)-1-thia-3-azaspiro[4.5]dec-2-en-4-one (3i) inhibits the activity of isoform 1 by 82.82%. This value is comparable to the known inhibitor-carbenoxolone. The IC50 value is twice the value determined by us for carbenoxolone, however inhibition of the enzyme isoform 2 to a lesser extent makes it an excellent material for further tests.

A Novel N-Tert-Butyl Derivatives of Pseudothiohydantoin as Potential Target in Anti-Cancer Therapy.

Tumors are currently more and more common all over the world; hence, attempts are being made to explain the biochemical processes underlying their development. The search for new therapeutic pathways, with particular emphasis on enzymatic activity and its modulation regulating the level of glucocorticosteroids, may contribute to the development and implementation of new therapeutic options in the treatment process. Our research focuses on understanding the role of 11ß-HSD1 and 11ß-HSD2 as factors involved in the differentiation and proliferation of neoplastic cells. In this work, we obtained the 9 novel N-tert-butyl substituted 2-aminothiazol-4(5H)-one (pseudothiohydantoin) derivatives, differing in the substituents at C-5 of the thiazole ring. The inhibitory activity and selectivity of the obtained derivatives in relation to two isoforms of 11ß-HSD were evaluated. The highest inhibitory activity for 11ß-HSD1 showed compound 3h, containing the cyclohexane substituent at the 5-position of the thiazole ring in the spiro system (82.5% at a conc. 10 µM). On the other hand, the derivative 3f with the phenyl substituent at C-5 showed the highest inhibition of 11ß-HSD2 (53.57% at a conc. of 10 µM). A low selectivity in the inhibition of 11ß-HSD2 was observed but, unlike 18ß-glycyrrhetinic acid, these compounds were found to inhibit the activity of 11ß-HSD2 to a greater extent than 11ß-HSD1, which makes them attractive for further research on their anti-cancer activity.

Synthesis of Novel 2-(Isopropylamino)thiazol-4(5H)-one Derivatives and Their Inhibitory Activity of 11ß-HSD1 and 11ß-HSD2 in Aspect of Carcinogenesis Prevention.

Glucocorticoid metabolism at the tissue level is regulated by two isoenzymes 11ß-hydroxysteroid dehydrogenase (11ß-HSD), which mutually convert biologically active cortisol and inactive cortisone. Recent research is focused on the role of 11ß-HSD1 and 11ß-HSD2 as autocrine factors of tumor cell proliferation and differentiation. Herein, we report the synthesis of novel 2-(isopropylamino)thiazol-4(5H)-one derivatives and their inhibitory activity for 11ß-HSD1 and 11ß-HSD2. The derivative containing the spiro system of thiazole and cyclohexane rings shows the highest degree of 11ß-HSD1 inhibition (54.53% at 10 µM) and is the most selective inhibitor of this enzyme among the tested compounds. In turn, derivatives containing ethyl and n-propyl group at C-5 of thiazole ring inhibit the activity of 11ß-HSD2 to a high degree (47.08 and 54.59% at 10 µM respectively) and are completely selective. Inhibition of the activity of these enzymes may have a significant impact on the process of formation and course of tumors. Therefore, these compounds can be considered as potential pharmaceuticals supporting anti-cancer therapy.

Application of ELISA Technique and Human Microsomes in the Search for 11ß-Hydroxysteroid Dehydrogenase Inhibitors.

The metabolic syndrome is defined by impaired carbohydrate metabolism and lipid disorders and often accompanied by hypertension, all of which will lead to obesity and insulin resistance. Glucocorticoids play a regulatory role in the metabolism of proteins, lipids, and carbohydrates. There is growing evidence for a role of glucocorticoids in the development of the metabolic syndrome. The most important factor that regulates the access of endogenous glucocorticoids to receptors after release of glucocorticoids and their diffusion into the cytoplasm of target cells is the steroid metabolism involving a microsomal enzyme, 11ß-hydroxysteroid dehydrogenase (11ß-HSD). The changes in intracellular glucocorticoid metabolism in the pathogenesis of obesity indicate the participation of modulation by 11ß-HSD1, which may represent a new therapeutic target for the treatment of diseases such as type 2 diabetes, visceral obesity, or atherosclerosis. The aim of our study was to determine the fast and effective method to assess inhibition activity of compounds in relation with 11ß-hydroxysteroid dehydrogenase. The material for this study was human liver and kidney microsomes. In this study we used ELISA technique using 96-well microplates coated with antibodies which were specific for analyzed enzymes. The method can quickly and efficiently measure the inhibition of both 11ß-HSD1 and 11ß-HSD2. This method can be used to search for and determine inhibitors of this enzyme. Cortisone and cortisol were used as the substrates for corresponding enzyme assays. Furthermore, 3-N-allyl-2-thiouracil derivatives were used by us for comparison purposes in developing the method, although, due to their structure, those derivatives have not previously been considered as potential inhibitors of 11ß-HSD1. 3-N-Allyl-2-thiouracil derivatives are a group worth considering, because by modifying their structure (e.g., by introducing other substituents into the pyrimidine ring) it will be possible to obtain an increase in the activity of compounds in this regard. In conclusion, this study shows an efficient and fast method of determining inhibition activity of compounds in relation with 11ß-hydroxysteroid dehydrogenase.

Synthesis of the N-methyl Derivatives of 2-Aminothiazol-4(5H)-one and Their Interactions with 11ßHSD1-Molecular Modeling and in Vitro Studies.

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is an enzyme that affects the body's cortisol levels. The inhibition of its activity can be used in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. In this study, we synthesized new derivatives of 2-(methylamino)thiazol-4(5H)-one and tested their activity towards inhibition of 11ß-HSD1 and its isoform - 11ß-HSD2. The results were compared with the previously tested allyl derivatives. We found out that methyl derivatives are weaker inhibitors of 11ß-HSD1 in comparison to their allyl analogs. Due to significant differences in the activity of the compounds, molecular modeling was performed, which was aimed at comparing the interactions between 11ß-HSD1 and ligands differing by substituent at the amine group (allyl vs. methyl). Modeling showed that the absence of the allyl group can lead to the rotation of whole ligand molecule which affects its interaction with the enzyme.

Assessment of the State of the Natural Antioxidant Barrier of a Body in Patients Complaining about the Presence of Tinnitus.

BACKGROUND: Tinnitus is defined as a phantom auditory perception, i.e., sound experience despite the lack of acoustic stimuli in the environment. The aim of this study was to assess the state of the natural antioxidant barrier of a body in patients complaining about the presence of tinnitus. MATERIAL AND METHODS: The study included a total of 51 patients aged from 20 to 62 years with diagnosed idiopathic tinnitus and 19 healthy subjects as a control group. All patients underwent the audiometric tone test, speech audiometry, distortion otoacoustic emission product testing, study of evoked auditory potentials of short latency, and biochemical analysis of venous blood concerning values of activity or concentration of glutathione, glutathione peroxidase, S-transferase, glutathione reductase superoxide dismutase, malondialdehyde, and ceruloplasmin as the selected parameters of oxidative stress. RESULTS: Disorders of the auditory pathway were not only limited to the cochlea but also covered its further episodes. Mean values of activity or concentration of the selected parameters of oxidative stress in the study and control groups showed reduced effectiveness of the body's natural antioxidant barrier. DISCUSSION: Patients complaining about the presence of tinnitus showed reduced effectiveness of the body's natural antioxidant barrier compared to the control group. CONCLUSIONS: The main indication to undertake further research on the functioning of the antioxidant barrier in people suffering from ailments in the form of tinnitus is to determine a suitable therapy aimed at improving the quality of life of these patients, which might be the administration of antioxidant medications.

Thiazolo[3,2-a]pyrimidin-5-one derivatives as a novel class of 11ß-hydroxysteroid dehydrogenase inhibitors.

11ß-hydroxysteroid type 1 dehydrogenase (11ß-HSD1) is an enzyme that increases tissue concentrations of cortisol. Selective inhibitors of this enzyme regulate the level of cortisol and thus play a key role in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. In this study the inhibitory activity of 29 thiazolo[3,2-a]pyrimidin-5-one derivatives on 11ß-HSD1 were investigated. Studies were carried out with pooled human liver microsomes. A lot of analyzed compounds show activity for inhibiting 11ß-HSD1 (up to 59.15% at concentration 10 µmol/l). Molecular docking simulation show that the molecule of the most active compound: 7-(cyclohexylmethyl)-2-iodomethyl-2,3-dihydrothiazolo[3,2-a]pyrimidin-5-one forms hydrogen bonds with Ala172, Leu171, Leu215 or Tyr177. In addition, the cycloalkane moiety can create the hydrophobic contacts with NADP+. For this compound also the most favourable Docking Score value was obtained. The most active compound only in the slight degree inhibits 11ß-HSD2 activity and is a selective inhibitor of 11ß-hydroxysteroid dehydrogenase type 1. Consequently it can have a real effect on the regulation of the cortisol level in the body.

A novel derivatives of thiazol-4(5H)-one and their activity in the inhibition of 11ß-hydroxysteroid dehydrogenase type 1.

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is an enzyme that catalyzes the conversion of inactive cortisone into physiologically active cortisol. Inhibiting the activity of this enzyme plays a key role in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. Therefore, new compounds that are selective inhibitors of this enzyme are constantly being looked for. In this work we present the synthesis of 2-(allylamino)thiazol-4(5H)-one derivatives by the reaction of N-allylthiourea with appropriate α-bromoesters. In the case of using of aliphatic α-bromoesters and α-bromo-ß-phenylesters, the reactions were carried out in a basic medium (sodium ethoxide) and the products were isolated with a yield of up to 68%. Derivatives containing spiro systems in which carbon C-5 of the thiazole ring is the linker atom were obtained in the presence of N,N-diisopropylethylamine. Some of the obtained compounds, at a concentration of 10 µM have activity in the inhibition of 11ß-HSD1 up to 71%. IC50 value for the most active compound: 2-(allylamino)-1-thia-3-azaspiro[4.5]dec-2-en-4-one is 2.5 µM. With a high degree of 11ß-HSD1 inhibition and a relatively large difference in the inhibition of 11ß-HSD1 and 11ß-HSD2 activity, this compound appears to be promising and should be subjected to further testing.

Change of the State of the Natural Antioxidant Barrier of a Body and Psychological Parameters in Patients Aged above 60.

BACKGROUND: The goal of this study is to assess the natural antioxidant barrier of the organism and selected psychological aspects of the aging process in patients above 60 years old. METHODS: The study included a total of 52 patients aged above 60 (mean age 67 ± 3.4) and 32 healthy subjects (mean age 22 ± 3.4) as a control group. All patients underwent psychological assessment using Test of Attentional Performance version 2.3 (TAP 2.3, four subtests: alertness, cross-modal integration, neglect with central task, and working memory) and biochemical analysis of venous blood concerning values of the selected parameters of oxidative stress (HT, GSH, GPXOS, GPXRBC, GRRBC1, SODRBC1, MDARBC1, NO2-/NO3-, and CP). RESULTS: Disorders of attention were observed mainly in elderly people, but an assumption that elderly people have developed more efficient ways of working memory use than younger people may be true. Results showed the reduced effectiveness of the body's natural antioxidant barrier in elderly people. Moderate positive and negative correlations among parameters of oxidative stress and psychological parameters were observed in the control group. DISCUSSION: Intensification of the attention deficits and oxidative stress may be observed as one of the pathogenic factors of age-dependent diseases.

Antioxidant effect of immediate- versus sustained-release melatonin in type 2 diabetes mellitus and healthy controls.

Oxidative damage has been suggested as the primary cause of aging and age-associated diseases including type 2-dependent diabetes mellitus (T2DM) and therefore there is a growing interest in exploring therapeutic potential of antioxidant agents including melatonin. In the present study, we analyzed red blood cell antioxidants and lipid peroxidation after 5 mg/daily immediate-release melatonin treatment of elderly T2DM patients and healthy elderly subjects in comparison with 2 mg/daily sustained-release melatonin treatment of elderly T2DM patients and healthy elderly subjects, to determine the antioxidant effect of different doses and formulations of melatonin in these groups. Our study revealed that there was no significant difference in antioxidant status of red blood cells measured by glutathione concentration and activities of GPx-1, CAT, GR, SOD-1 and MDA levels, after supplementation with 2 mg-sustained release melatonin or with 5 mg-immediate release melatonin, either in T2DM or in healthy elderly subjects. These results suggest that both preparations may exert similar therapeutic effect related to melatonin's action on antioxidant defense system.

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

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.