Dimitrios Kouretas

• University of Thessaly

Long-distance running has become increasingly popular. Cardiovascular adaptations to exercise are relevant to the specific sports and this is also the case in long-distance running. Significant changes regarding inflammatory and endothelial markers along with indices of oxidative stress are observed in marathon and ultra-marathon runners. However,...

(1) Background: Human health risks and hazards from chemical substances are well regulated internationally. However, cardiotoxicity, is not defined as a stand-alone hazard and therefore there are no defined criteria for the classification of substances as cardiotoxic. Identifying and regulating substances that cause cardiovascular adverse effects w...

Recently, an increasing number of chemical compounds are being characterized as endocrine disruptors since they have been proven to interact with the endocrine system, which plays a crucial role in the maintenance of homeostasis. Glyphosate is the active substance of the herbicide Roundup®, bisphenol A (BPA) and di (2-ethylhexyl) phthalate (DEHP) a...

Micronutrients constitute an adjuvant treatment for respiratory viral infections. Since there is no effective antiviral therapy for COVID-19 yet, adjuvant intervention for the survival of critically ill patients may be significant. Search of the PubMed, CINAHL and Cochrane databases was carried out to find human studies investigating the prognostic...

Mastic gum is a resinous sap produced by Pistacia lentiscus growing in the island of Chios (Greece) and has been recognized since Antiquity for its distinctive aroma as well as medical properties (antimicrobial, antioxidant, anti-inflammatory ones). The oral absorption of Chios Mastic gum (an insoluble polymer of poly-β-myrcene is among the most ab...

Over the last decades, human activities prompted the high production and widespread use of household chemical products, leading to daily exposure of humans to several chemicals. The objective of this study was to investigate the frequency of chemicals’ use by children and parents in Greece and estimate the level of risk awareness and understanding...

The present Special Issue of Antioxidants, entitled The Significance of Redox Biomarkers in the Evaluation of the Antioxidant Profile In Vitro and In Vivo, ten research articles emphasize the significance of adopting reliable redox biomarkers to determine the antioxidant activities of bioactive compounds in vitro and to assess blood and tissue redo...

SARS-CoV-2 is the coronavirus that originated in Wuhan in December 2019 and has spread globally. Studies have shown that smokers are less likely to be diagnosed with or be hospitalized for COVID-19 but, once hospitalized, have higher odds for an adverse outcome. We have previously presented the potential interaction between SARS-CoV-2 Spike glycopr...

The coronavirus disease (COVID)-19 pandemic is a major challenge for the health systems worldwide. Acute respiratory distress syndrome (ARDS), is one of the most common complications of the COVID-19 infection. The activation of the coagulation system plays an important role in the pathogenesis of ARDS. The development of lung coagulopathy involves...

COVID-19 pandemic mitigation strategies are mainly based on social distancing measures and healthcare system reinforcement. However, many countries in Europe and elsewhere implemented strict, horizontal lockdowns because of extensive viral spread in the community which challenges the capacity of the healthcare systems. However, strict lockdowns hav...

Background: Diabetes is regarded as an epidemiological threat for the twenty-first century. Phytochemicals with known pharmaceutical properties have gained interest in the field of alleviating secondary complications of diseases. Such a substance is crocin, a basic constituent of saffron (Crocus sativus). The present study aimed at examining the b...

Subsequently to the publication of this paper, the authors have realized that the name of the seventh listed author, Dimitrios Stagos, was spelt incorrectly (it appeared as 'Stagkos' in print). The corrected author list is shown above. The authors regret that the name of the seventh author on the paper was spelt incorrectly, and apologize to the re...

Anthracyclines are commonly used anticancer drugs with well‑known and extensively studied cardiotoxic effects in humans. In the clinical setting guidelines for assessing cardiotoxicity are well‑established with important therapeutic implications. Cardiotoxicity in terms of impairment of cardiac function is largely diagnosed by echocardiography and...

Obesity and thus, lipotoxicity, is a major health risk factor. Modern exposure to environmental chemicals has contributed significantly to the obesity epidemic. The purpose of this study was to assess, via telemedicine and using bioelectrical impedance analysis (BIA) in schools, the levels of adiposity and other body composition parameters of Greek...

In this research, a model for the estimation of antioxidant content in cherry fruits from multispectral imagery acquired from drones was developed, based on machine learning methods. For two consecutive cultivation years, the trees were sampled on different dates and then analysed for their fruits' radical scavenging activity (DPPH) and Folin-Cioca...

Identification of novel biomarkers of contrast-induced nephropathy (CIN)that may more accurately detect renal function changes; reflect kidney damage; assist monitoring; and elucidate pathophysiology attract considerable scientific attention nowadays. To evaluate novel biomarkers of nephrotoxicity in blood/tissue samples of a CIN model, 10 New Zeal...

Whey protein, a by-product of the cheese industry, can be putatively used as a functional food due to its beneficial health properties. The main objective of the present study was to assess in vivo the effect of a sheep/goat whey protein on the plasma amino acid profile and mammalian target of rapamycin (mTOR), a regulator of skeletal myogenesis. A...

Coffee is a highly consumed beverage with many putative beneficial health effects, however these often come from observational studies. In the current work, a lightly roasted coffee extract that has previously been reported to exhibit potent antioxidant properties was administered for two weeks in rats to examine the potential improvement of blood...

Coffee consumption is very popular throughout the world and apart from its stimulating effect, various beneficial health effects have been attributed to it. However, most studies are either observational, or do not analyze the majority of tissues. In the current work, a lightly roasted coffee extract was administered for two weeks in the water of r...

Over the last decades, the scientific findings stressing the beneficial health implications of plant-derived compounds (i.e., plant extracts rich in polyphenols) have been increased significantly. Assessing the properties of such compounds throughout the redox continuum is a common practice for the evaluation of their dynamics in reinforcing the an...

Wild or semi-wild edible greens (chórta) are an integral part of the traditional Greek Mediterranean diet due to their nutritional value, containing various phytonutrients beneficial to human health. Water-based decoctions of chórta are widely consumed in Greek alternative medicine as health promoting agents. This study examined the chemical profil...

Coffee is a popular beverage that contains various bioactive compounds. However, its molecular mechanism of action is not fully elucidated. In this context, two previously characterized coffee extracts, a lightly roasted and the corresponding green one, were investigated for their effect on nuclear factor erythroid 2‑related factor 2 (Nrf2) target...

Although the use of nutritional supplements by adult athletes has been extensively studied, information on supplements consumption by adolescent athletes is still limited. The present study reports on the use of nutritional supplements contaminated with banned doping substances among 170 recreational adolescent athletes from eleven, randomly select...

This study assessed the potential adverse health effects of long-term low-dose exposure to chemical mixtures simulating complex real-life human exposures. Four groups of Sprague Dawley rats were administered mixtures containing carbaryl, dimethoate, glyphosate, methomyl, methyl parathion, triadimefon, aspartame, sodium benzoate, calcium disodium et...

Imidacloprid (IMI) is a systemic, chloro-nicotinyl insecticide classified in Regulation N° 1272/2008 of the European Commision as “harmful if swallowed and very toxic to aquatic life, with long-lasting effects”. IMI is metabolized in vitro both by aldehyde oxidase (AOX) (reduction) and by cytochrome P450s enzymes (CYPs). In the present study, the A...

Coffee is one of the most highly consumed beverages with potential beneficial health implications, however its molecular mechanism of action has not been completely elucidated yet. To that cause, the polyphenolic composition of different coffee extracts (from Light, Medium and Dark roasts as well as green beans) was examined by UHPLC-HRMS analysis,...

Olive oil (OO) constitutes the basis of the Mediterranean diet, andit seems that its biophenols, such as hydroxytyrosol (HT) mayscavenge free radicals, attracting distinct attention due to their ben-eficial effects in many pathological conditions, such as cancer. Theaim of the present study was to examine the antioxidant proper-ties of an EVOO tota...

The present study focused on the elucidation of the putative anticancer potential of quercetin. The anticancer activity of quercetin at 10, 20, 40, 80 and 120 µM was assessed in vitro by MMT assay in 9 tumor cell lines (colon carcinoma CT‑26 cells, prostate adenocarcinoma LNCaP cells, human prostate PC3 cells, pheocromocytoma PC12 cells, estrogen r...

Pomegranate has been used therapeutically for centuries. The aim of the present study was to examine the effects of pomegranate juice (PJ) supplementation on complete blood count (CBC), glucose, blood lipids and C-reactive protein (CRP) in healthy subjects. A total of 5 males and 5 females (aged 31.8±6.6 years, weighing 66.2±12.9 kg) were randomly...

Currently, there is a great interest in the production of animal feed with antioxidant activity. The aim of this study was to examine the potential antioxidant effects of a feed supplemented with grape pomace (GP), a winery by-product with high environmental load, in chickens. Broilers of 15 days post birth were separated into two groups fed either...

Peppermint leaves are widely used for the symptomatic treatment of digestive disorders. Previous studies have shown significant effects of its natural products on human enzyme activity; however, there is no study available concerning the effects of peppermint tea on metabolizing enzymes in humans. Aim of the present study was to investigate the eff...

In real life, consumers are exposed to complex mixtures of chemicals via food, water and commercial products consumption. Since risk assessment usually focuses on individual compounds, the current regulatory approach doesn’t assess the overall risk of chemicals present in a mixture. This study will evaluate the cumulative toxicity of mixtures of di...

Measuring the antioxidant capacity of foods is essential, as a means of quality control to ensure that the final product reaching the consumer will be of high standards. Despite the already existing assays with which the antioxidant activity is estimated, new, faster and low cost methods are always sought. Therefore, we have developed a novel color...

The aim of the present study was to investigate the molecular mechanisms through which sheep/goat whey protein exerts its antioxidant activity. Thus, it was examined whey protein's effects on the expression of transcription factor, nuclear factor-like 2 (Nrf2) and on the expression and activity of a number of antioxidant and phase II enzymes, super...

Objective of the study was the evaluation of the effect of melatonin treatment on fertility and antioxidant capacity of indigenous Greek breed Karagouniko ewes during the summer period. In total, 70 ewes were allocated into groups C (control, n=38) or M (melatonin treated, n=32). Before onset of the breeding season, melatonin implants (Regulin, Cev...

Excessive production of reactive oxygen species (ROS) may cause endothelial dysfunction and consequently vascular disease. In the present study, the possible protective effects of sheep whey protein (SWP) from tert-butyl hydroperoxide- (tBHP-) induced oxidative stress in endothelial cells (EA.hy926) were assessed using oxidative stress biomarkers....

In the present study, a polyphenolic byproduct from olive mill wastewater (OMWW) was used for making piglet feed with antioxidant activity. For examining the antioxidant capacity of the feed, 30 piglets of 20 d old were divided into two groups receiving basal or experimental feed for 30 d. Blood and tissue samples were drawn at days 2, 20, 35 and 5...

Background/aim: The novel static (sORP) and capacity (cORP) oxidation-reduction potential markers were examined for assessing oxidative stress in plasma of patients with sepsis. Moreover, the possible effect of obesity-induced oxidative stress on patients with sepsis was investigated. Materials and methods: sORP and cORP markers, as well as the...

The synthesis of 17 novel conformationally constrained pyrazole derivatives is reported herein, along with the assessment of their anti-proliferative and anti-angiogenic activities. The evaluation of their inhibitory effect on cell proliferation against HepG2, HeLa, and MCF-7 cells revealed the pyrrolo[2,3-g]indazole 23 as a potent inhibitor of cel...

In the present study, a ceramic membrane microfiltration method was used for the separation of two liquid products, the downstream permeate and the upstream retentate, from olive mill wastewater (OMWW). These liquid products were examined for their antioxidant activity by incorporating them into broilers' feed. Twenty four broilers 13 d old were di...

The aim of the present study was to investigate the use of static (sORP) and capacity ORP (cORP) oxidation-reduction potential markers as measured by the RedoxSYS Diagnostic System in plasma, for assessing eccentric exercise-induced oxidative stress. Nineteen volunteers performed eccentric exercise with the knee extensors. Blood was collected befor...

The electronic cigarette (e-cig) is an invention of the past few years and its popularity is rapidly growing all over the world. A rapid multicomponent analytical protocol for the analysis of the replacement liquids (e-liquids) of e-cig was developed using gas (GC) and liquid chromatography (LC)-mass spectrometry (MS). GC-MS-based methods were deve...

Objectives: The aim of the study was to test a novel method for assessing oxidative stress, the RedoxSYS™ diagnostic system, a holistic, fast, minimally invasive, and requiring small sample volume method, that measures two parameters, the static (sORP) and the capacity (cORP) oxidation-reduction potential. Methods: The redox status of 14 athlete...

The aim of the present study was to investigate the antiangiogenic potential of a grape stem extract against tube formation by human endothelial cells (EA.hy926). The results showed that at low and non-cytotoxic concentrations (50 and 100 μg/ml) the grape stem extract inhibited tube formation, indicating a possible antiangiogenic activity. Moreover...

The past two to three decades have seen an explosion in analytical areas related to 'omic' technologies. These advancements have reached a point where their application can be and are being used as a part of exercise physiology and sport performance research. Such advancements have drastically enabled researchers to analyze extremely large groups o...

Background/Objectives: Sepsis is one of the most important causes of mortality in the developed world, where almost two-thirds of the population suffer from obesity. Therefore, the coexistence of both conditions has become frequent in clinical practice and a growing number of clinical studies attempts to examine the potential effect of obesity on s...

A grape pomace extract enhanced antioxidant mechanisms in muscle and endothelial cells both in the absence and in the presence of oxidative stress-induced agent tert-butyl hydroperoxide (tBHP). In particular, muscle (C2C12) and endothelial (EA.hy926) cells were treated with the extract at noncytotoxic concentrations for 24 h, and the oxidative stre...

Exhaustive exercise is a generator of free radicals and reactive species in mammals. Allopurinol is a known inhibitor of xanthine oxidase, a source of free radicals during exercise. In this study, the influence of allopurinol on the metabolic profile of blood plasma of rats that had undergone exhaustive swimming was investigated by GC-MS. Rats were...

The aim of the present study was the assessment of the antioxidant effects of pomegranate juice (PJ) consumption in humans. Thus, 14 healthy volunteers consumed PJ daily for a period of 15days and the changes of oxidative stress markers in their blood were assessed at four different time points, immediately before the experiment (T1), after 15days...

In this study we examined the glycaemic index (GI) and glycaemic load (GL) of a functional food product, which contains ewe-goat whey protein and carbohydrates in a 1:1 ratio. Nine healthy volunteers, (age, 23.3 ± 3.9 years; body mass index, 24.2 ± 4.1 kg·m2; body fat %, 18.6 ± 10.0) randomly consumed either a reference food or amount of the test f...

The inhibitory potency of thirteen polyphenolic extracts obtained from vinification byproducts of Greek varieties of Vitis vinifera against glycogen phosphorylase (GP) has been studied by kinetic experiments. GP is an enzyme involved in glucose homeostasis and a molecular target for the discovery of new hypoglycemic agents. Studies have shown that...

Findings about involvement of reactive oxygen species (ROS) not only in defense processes, but also in a number of pathologies, stimulated discussion about their role in etiopathogenesis of various diseases. Yet questions regarding the role of ROS in tissue injury, whether ROS may serve as a common cause of different disorders or whether their unco...

The aim of the study was the assessment of the antioxidant activity of a polyphenolic extract from olive mill wastewater that was encapsulated in maltodextrin and whey protein. So, a polyphenolic extract isolated from olive mill wastewater was encapsulated in maltodextrin under 7 different conditions as well as in whey protein under 5 different con...

Elite water polo athletes, in order to meet their goals and team expectations, undergo a heavy training and competition program throughout the year. The aim of this study was to identify and record the variations of the selected biochemical and hematological parameters related to health, injuries and performance in 14 elite female water polo player...

The purpose of this study was to examine the effect of α-lipoic acid (LA) supplementation on blood redox status in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Eight adults with G6PD deficiency (D group) and eight controls with normal G6PD levels (N group) participated in this study. Participants received LA (600mg/day) for...

Grape extracts and wine have been studied widely due to their beneficial effects on human health. However, there are only few studies from grape stems extracts. Therefore, the main objective of the present study was the assessment in stem extracts from Greek Vitis vinifera varieties of the total polyphenolic content (TPC), the identification of the...

Elite water polo athletes, in order to meet their goals and team expectations, undergo a heavy training and competition program throughout the year. The aim of this study was to identify and record the variations of the selected biochemical and hematological parameters related to health, injuries and performance in 14 elite female water polo player...

a b s t r a c t Elite athletes undergo heavy training programs throughout the year. The aim of the present study was to evaluate blood biomarkers of redox status, oxidative stress, inflammation and angiogenesis over the course of a competitive season in elite female water polo players. The biomarkers were evaluated in four distinct phases of an ath...

Fruits, such as grapes, are essential food of the Mediterranean diet. Grape extracts have potent antioxidant and chemopreventive properties in vitro. Numerous studies have examined the effects of plant extract administration on redox status at rest in animals and humans but their results are controversial. However, there are no studies comparing th...

Legumes and the polyphenolic compounds present in them have gained a lot of interest due to their beneficial health implications. Dietary polyphenolic compounds, especially flavonoids, exert antioxidant properties and are potent inhibitors of xanthine oxidase (XO) activity. XO is the main contributor of free radicals during exercise but it is also...

Flavonoids identified in aqueous extract of Lathyrus laxiflorus subsp. Laxiflorus

Legumes are considered to have beneficial health implications, which have been attributed to their phytochemical content. Polyphenols are considered the most important phytochemical compounds extensively studied for their antioxidant properties. The aim of the present study was to examine the effects of potent antioxidant legume plant extracts on x...

Eukaryotic cells generally function in a reduced state, but an amount of reactive species is essential for several biochemical processes. The antioxidant network is the defensive mechanism that occurs when the concentration of reactive species exceeds a threshold. Polyphenolic compounds present in plant extracts are potent antioxidants in vitro, bu...

Exercise-induced arterial hypoxemia (EIAH), characterized by decline in arterial oxyhemoglobin saturation (SaO(2)), is a common phenomenon in endurance athletes. Acute intensive exercise is associated with the generation of reactive species that may result in redox status disturbances and oxidation of cell macromolecules. The purpose of the present...

A number of in vitro and in vivo studies have investigated the potential preventive activity of grape extracts against different diseases, and have mostly focused on their antioxidant properties. The present study examined the effects of 21 extracts from stem, skin and berry from Greek grape varieties on the activity of enzymes involved in regulati...

Data on redox balance in response to marathon swimming are lacking, whereas findings from studies using other types of ultraendurance exercise are controversial. The aim of the present study was to investigate the effect of ultramarathon swimming on selective blood oxidative stress markers. Five well-trained male swimmers aged 28.8 (6.0) years part...

Nucleoside analogues play an important role in the development of antitumor and antiviral agents. Specific sugar modified pyranonucleosides, like the keto and exocyclic methylene nucleosides, have been studied for their biological properties, but there is little information regarding their antioxidant activity. The present study reports the antioxi...

To determine the time-course changes of cell-free plasma DNA (cfDNA) following heavy exercise. cfDNA concentration, C-reactive protein levels (hs-CRP), uric acid concentration (UA), creatine kinase activity (CK) were measured before and post-exercise (immediately post, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 8h, 10h, 24h). cfDNA increased (15-fold) 30-min po...

Albumin is a protein present in almost all kinds of mammalian cells. It has binding sites for several molecules, and possesses antioxidant and other important properties. The aim of this study was to examine the effects of 2 different oxidative stress stimuli exercise and allopurinol administration and their combination on albumin concentration in...

Exercise-induced muscle damage is associated with an acute-phase inflammatory response characterized by phagocyte infiltration into muscle and free radical production. Although soccer includes intense eccentric muscle actions that cause muscle damage, the oxidative stress responses after a soccer game are currently unknown. The present investigatio...

This study investigated whether selected oxidative stress markers measured in blood adequately reflect redox status in skeletal muscle, heart, and liver. Several markers were determined after implementing two treatments known to affect redox status, namely exercise and allopurinol administration. Xanthine oxidase, thiobarbituric acid-reactive subst...

High-intensity exercise is associated with increased oxidative stress. Rowing is very demanding requiring maintenance of high power mostly produced from aerobic metabolism. The present study aimed at investigating selective blood oxidative stress markers in response to a rowing race simulation test, consisting of 2,000 m maximal effort on a rowing...

Salvia is one of the largest and most important genus of the Labiatae family. In Greek soil, twelve species can be found. We chose to investigate the chemical profile of six taxa (Salvia officinalis, S. fruticosa, S. sclarea, S. argentea, S. pomifera ssp. pomifera and S. pomifera ssp. calycina). The aerial parts of these plants were extracted with...

Lotus is a genus of Leguminosae family which is consist of about 100 species which are native in Mediterranean and N. America countries. The specie L. edulis is an annual edible herb which is known in Greece with the common name 'Peratzouni'. The methanolic extract obtained from the aerial part of this plant posses remarkable antioxidant and chemop...

The aim of this study was to examine the effect of allopurinol, a xanthine oxidase inhibitor, on oxidative stress and physical performance after swimming until exhaustion in rats. Blood and gastrocnemius muscle samples were collected before, immediately after, and 5h after exercise and the respective timepoints after allopurinol administration. Xan...

Allopurinol is an inhibitor of xanthine oxidase. Xanthine oxidase is a major contributor of free radicals during exercise. Previous studies have shown that free radicals are vital for physiological adaptations in exercise. The purpose of this study was to examine the effects of allopurinol, exercise and their combination on protein carbonyls (PC),...

Exercise is associated with the generation of reactive oxygen and nitrogen species. This study examined the oxidative stress in response to a novel volitional fatigue test. Eleven male college students performed a volitional fatigue test consisting of shuttle runs with a tennis racquet in the hand towards the left and right sidelines within the ten...