Silymarin is an extract obtained from the seeds of milk thistle (Sylibum marianum L., Asteraceae) and contains several structurally related flavonolignans and a small family of flavonoids. Mouse spleen cells represent highly sensitive primary cells suitable for studying the pharmacological potential and biofunctional properties of natural substances. Cultivation of splenocytes for 24 h under standard culture conditions (humidity, 37 °C, 5% CO2, atmospheric oxygen) resulted in decreased viability of splenocytes compared to intact cells. A cytoprotective effect of silybin (SB), silychristin (SCH) and 2,3-dehydrosilybin (DHSB) was observed at concentrations as low as 5 µmol/ml. At 50 µmol/ml, these substances restored and/or stimulated viability and mitochondrial membrane potential and had anti-apoptotic effect in the order SB > DHSB > SCH. The substances demonstrated a concentration-dependent activity in restoring the redox balance based on the changes in the concentration of reactive oxygen species (ROS), hydrogen peroxide (H2O2) and nitric oxide. This was in the order DHSB > SCH > SB, which correlated with the suppressed expression of nuclear factor erythroid 2-related factor 2 (Nrf2), catalase and glutathione peroxidase. The strong stimulation of the superoxide dismutase 1 gene converting ROS to H2O2 points to its dominant role in the maintaining redox homeostasis in splenocytes, which was disrupted by oxidative stress due to non-physiological culture conditions. Our study showed significant differences in the cytoprotective, antioxidant and anti-apoptotic activities of SB, SCH, and DHSB on splenocytes exposed to mild and AAPH-induced oxidative stress.

• Klíčová slova
• 2,3-dehydrosilybin, Apoptosis, Mouse splenocytes, Redox balance, Silybin, Silychristin, Viability,
• MeSH
• antioxidancia * farmakologie   MeSH
• apoptóza * účinky léků   MeSH
• cytoprotekce * účinky léků   MeSH
• faktor 2 související s NF-E2 metabolismus   MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• silibinin MeSH
• silymarin * farmakologie   analogy a deriváty   MeSH
• slezina * cytologie   účinky léků   metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia * MeSH
• dehydrosilybin MeSH Prohlížeč
• faktor 2 související s NF-E2 MeSH
• oxid dusnatý MeSH
• peroxid vodíku MeSH
• reaktivní formy kyslíku MeSH
• silibinin MeSH
• silychristin MeSH Prohlížeč
• silymarin * MeSH

Disproportion between reactive oxygen species (ROS) production and the body's antioxidant system can cause oxidative stress, which is considered a common denominator in various pathological conditions, including cardiovascular diseases, aging, and cognitive disorders. The generation of free radicals, which occurs through partial reduction of oxygen, can quickly overwhelm the endogenous antioxidant system capacity of the cell. This causes lipid, protein, DNA and RNA damage, inflammation, and overall cell degeneration, which can be mitigated by various antioxidants. However, their use in human medicine did not bring the expected effect. Molecular hydrogen (H2), due to its unique physical and chemical properties, provides a number of benefits for alleviating oxidative stress. H2 is superior to conventional antioxidants as it can selectively reduce (.)OH radicals while preserving important ROS that are otherwise used for normal cell signaling. Key words Oxidative stress, Cardiovascular diseases, Molecular hydrogen, ROS, Inflammation.

• MeSH
• antioxidancia * terapeutické užití   farmakologie   MeSH
• kardiovaskulární nemoci * metabolismus   prevence a kontrola   farmakoterapie   MeSH
• lidé MeSH
• oxidační stres * účinky léků   fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• vodík * terapeutické užití   farmakologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antioxidancia * MeSH
• reaktivní formy kyslíku MeSH
• vodík * MeSH

Bone marrow stromal cells (BMSCs) play a significant role in bone metabolism as they can differentiate into osteoblasts, bone marrow adipocytes (BMAds), and chondrocytes. BMSCs chronically exposed to nutrient overload undergo adipogenic programming, resulting in bone marrow adipose tissue (BMAT) formation. BMAT is a fat depot transcriptionally, metabolically, and morphologically distinct from peripheral adipose depots. Reactive oxygen species (ROS) are elevated in obesity and serve as important signals directing BMSC fate. ROS produced by the NADPH oxidase (NOX) family of enzymes, such as NOX4, may be responsible for driving BMSC adipogenesis at the expense of osteogenic differentiation. The dual nature of ROS as both cellular signaling mediators and contributors to oxidative stress complicates their effects on bone metabolism. This review discusses the complex interplay between ROS and BMSC differentiation in the context of metabolic bone diseases.Special attention is paid to the role of NOX4-ROS in regulating cellular processes within the bone marrow microenvironment and potential target in metabolic bone diseases.

• Klíčová slova
• NADPH oxidase, ROS, bone fragility, bone marrow adipose tissue, bone marrow stromal cells, obesity, senescence,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

In this work, we used splenocytes from healthy mice to study the effects of the two most commonly used cell culture media (A, B) with different compositions of redox reagents. The incubation of cells for 24 h resulted in a significant decrease in viability and metabolic activity of splenocytes, and the negative effects of incubation in medium B were more pronounced. In standard conditions, oxidative stress in cells was manifested by reduced mitochondrial potential, and this effect correlated with the transition of 58.3% of cells to the early stage of apoptosis under reducing conditions of medium A and up to 66.1% of cells under super-reducing conditions in medium B, suggesting altered cell physiology. High levels of ROS/RNS activated transcription factor Nrf2, superoxide dismutase 1, and catalase. The higher mRNA levels of these genes were under the conditions of medium B, whose super-reducing environment in combination with the environment of conventional incubators proved to be less suitable for the cells compared to medium A. Treatment of the cells with a lower concentration (10 µg/ml) of oleoresin obtained from the microalga H. pluvialis partially eliminated the negative effects of cultivation. Higher concentration of oleoresin (40 µg/ml) was slightly cytotoxic, due to the significant antioxidant effect of astaxanthin, the main bioactive component of the extract, which eliminated most of the ROS/RNS acting as signalling molecules. This study shows that the standard culture conditions do not reflect the physiological in vivo cell conditions; therefore, they are not generally suitable for incubation of all cell types.

• Klíčová slova
• Heamatococcus pluvialis, Mouse spleen cells, Oleoresin, Oxidative stress, Standard culture conditions,
• MeSH
• Chlorophyta * metabolismus   MeSH
• kultivační média speciální metabolismus   MeSH
• mikrořasy * metabolismus   MeSH
• myši MeSH
• pilotní projekty MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rostlinné extrakty metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kultivační média speciální MeSH
• oleoresins MeSH Prohlížeč
• reaktivní formy kyslíku MeSH
• rostlinné extrakty MeSH

A physiological level of oxygen/nitrogen free radicals and non-radical reactive species (collectively known as ROS/RNS) is termed oxidative eustress or "good stress" and is characterized by low to mild levels of oxidants involved in the regulation of various biochemical transformations such as carboxylation, hydroxylation, peroxidation, or modulation of signal transduction pathways such as Nuclear factor-κB (NF-κB), Mitogen-activated protein kinase (MAPK) cascade, phosphoinositide-3-kinase, nuclear factor erythroid 2-related factor 2 (Nrf2) and other processes. Increased levels of ROS/RNS, generated from both endogenous (mitochondria, NADPH oxidases) and/or exogenous sources (radiation, certain drugs, foods, cigarette smoking, pollution) result in a harmful condition termed oxidative stress ("bad stress"). Although it is widely accepted, that many chronic diseases are multifactorial in origin, they share oxidative stress as a common denominator. Here we review the importance of oxidative stress and the mechanisms through which oxidative stress contributes to the pathological states of an organism. Attention is focused on the chemistry of ROS and RNS (e.g. superoxide radical, hydrogen peroxide, hydroxyl radicals, peroxyl radicals, nitric oxide, peroxynitrite), and their role in oxidative damage of DNA, proteins, and membrane lipids. Quantitative and qualitative assessment of oxidative stress biomarkers is also discussed. Oxidative stress contributes to the pathology of cancer, cardiovascular diseases, diabetes, neurological disorders (Alzheimer's and Parkinson's diseases, Down syndrome), psychiatric diseases (depression, schizophrenia, bipolar disorder), renal disease, lung disease (chronic pulmonary obstruction, lung cancer), and aging. The concerted action of antioxidants to ameliorate the harmful effect of oxidative stress is achieved by antioxidant enzymes (Superoxide dismutases-SODs, catalase, glutathione peroxidase-GPx), and small molecular weight antioxidants (vitamins C and E, flavonoids, carotenoids, melatonin, ergothioneine, and others). Perhaps one of the most effective low molecular weight antioxidants is vitamin E, the first line of defense against the peroxidation of lipids. A promising approach appears to be the use of certain antioxidants (e.g. flavonoids), showing weak prooxidant properties that may boost cellular antioxidant systems and thus act as preventive anticancer agents. Redox metal-based enzyme mimetic compounds as potential pharmaceutical interventions and sirtuins as promising therapeutic targets for age-related diseases and anti-aging strategies are discussed.

• Klíčová slova
• Aging, Antioxidants, Metals, Oxidative stress, ROS, Signaling pathways, Toxicity,
• MeSH
• antioxidancia * MeSH
• chronická nemoc MeSH
• lidé MeSH
• oxidační stres * MeSH
• reaktivní formy kyslíku MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antioxidancia * MeSH
• reaktivní formy kyslíku MeSH

Carotenoids are the most abundant lipid-soluble phytochemicals and are used as dietary supplements to protect against diseases caused by oxidative stress. Astaxanthin, a xanthophyll carotenoid, is a very potent antioxidant with numerous beneficial effects on cellular functions and signaling pathways. In this study, using spleen cells from healthy Balb/c mice, we report the bio-functional effects of an astaxanthin-rich extract (EXT) prepared from the microalga Haematococcus pluvialis and its astaxanthin monoesters-rich fraction (ME) and astaxanthin diesters-rich fraction (DE) obtained by fractionation of EXT using countercurrent chromatography (CCC). After incubation under standard culture conditions (humidity, 37 °C, 5% CO2, atmospheric oxygen), the viability of untreated splenocytes, as determined by the trypan blue exclusion assay, the MTT assay, and the neutral red assay, decreases to approximately 75% after 24 h compared with naïve splenocytes. This effect correlated with the decrease in mitochondrial membrane potential and the transition of ~59% of cells to the early stage of apoptosis, as well as with the decreased ROS production, indicating that hyperoxia in cell-culture deteriorates cell functions. They are restored or stimulated by co-cultivation with EXT, ME, and DE up to 10 µg/mL in the order EXT > DE > ME, suggesting that esterification increases bioavailability to cells in vitro. ROS and H2O2 concentrations reflect mRNA transcriptional activity of Nrf2, superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 1, as well as SOD-mediated ROS conversion, whereas they inversely correlate with iNOS-mediated NO production. The highest-tested concentration of EXT, ME, and DE (40 µg/mL) is detrimental to cells, probably because of the overwhelming scavenging activity of astaxanthin and its esters for the reactive oxygen/nitrogen species required for cellular functions and signal transduction at low physiological concentrations. In this study, we demonstrate that differential activities of ME and DE contribute to the final antioxidant and cytoprotective effects of astaxanthin extract, which is beneficial in preventing a wide range of ROS-induced adverse effects, with DE being more effective. In addition, the selection of physioxia-like conditions for pharmacological research is highlighted.

• Klíčová slova
• Haematococcus pluvialis, astaxanthin, countercurrent chromatography (CCC), diesters, monoesters, mouse, oxidative stress, splenocytes, viability,
• Publikační typ
• časopisecké články MeSH

Sperm motility is one of the major determinants of male fertility. Since sperm need a great deal of energy to support their fast movement by active metabolism, they are thus extremely vulnerable to oxidative damage by the reactive oxygen species (ROS) and other free radicals generated as byproducts in the electron transport chain. The present study is aimed at understanding the impact of a mitochondrial oxidizing/reducing microenvironment in the etiopathology of male infertility. We detected the mitochondrial DNA (mtDNA) 4,977 bp deletion in human sperm. We examined the gene mutation of ATP synthase 6 (ATPase6 m.T8993G) in ATP generation, the gene polymorphisms of uncoupling protein 2 (UCP2, G-866A) in the uncoupling of oxidative phosphorylation, the role of genes such as manganese superoxide dismutase (MnSOD, C47T) and catalase (CAT, C-262T) in the scavenging system in neutralizing reactive oxygen species, and the role of human 8-oxoguanine DNA glycosylase (hOGG1, C1245G) in 8-hydroxy-2'-deoxyguanosine (8-OHdG) repair. We found that the sperm with higher motility were found to have a higher mitochondrial membrane potential and mitochondrial bioenergetics. The genotype frequencies of UCP2 G-866A, MnSOD C47T, and CAT C-262T were found to be significantly different among the fertile subjects, the infertile subjects with more than 50% motility, and the infertile subjects with less than 50% motility. A higher prevalence of the mtDNA 4,977 bp deletion was found in the subjects with impaired sperm motility and fertility. Furthermore, we found that there were significant differences between the occurrences of the mtDNA 4,977 bp deletion and MnSOD (C47T) and hOGG1 (C1245G). In conclusion, the maintenance of the mitochondrial redox microenvironment and genome integrity is an important issue in sperm motility and fertility.

• MeSH
• DNA-glykosylasy genetika   metabolismus   MeSH
• frekvence genu MeSH
• lidé MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• mitochondriální DNA genetika   metabolismus   MeSH
• mitochondrie genetika   metabolismus   MeSH
• motilita spermií fyziologie   MeSH
• mužská infertilita genetika   patologie   MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku farmakologie   MeSH
• polymorfismus genetický MeSH
• spermie metabolismus   fyziologie   MeSH
• superoxiddismutasa genetika   metabolismus   MeSH
• uncoupling protein 2 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA-glykosylasy MeSH
• mitochondriální DNA MeSH
• oxoguanine glycosylase 1, human MeSH Prohlížeč
• peroxid vodíku MeSH
• superoxiddismutasa MeSH
• UCP2 protein, human MeSH Prohlížeč
• uncoupling protein 2 MeSH

Reactive oxygen species are an important element of redox regulation in cells and tissues. During physiological processes, molecules undergo chemical changes caused by reduction and oxidation reactions. Free radicals are involved in interactions with other molecules, leading to oxidative stress. Oxidative stress works two ways depending on the levels of oxidizing agents and products. Excessive action of oxidizing agents damages biomolecules, while a moderate physiological level of oxidative stress (oxidative eustress) is necessary to control life processes through redox signaling required for normal cellular operation. High levels of reactive oxygen species (ROS) mediate pathological changes. Oxidative stress helps to regulate cellular phenotypes in physiological and pathological conditions. Nrf2 (nuclear factor erythroid 2-related factor 2, NFE2L2) transcription factor functions as a target nuclear receptor against oxidative stress and is a key factor in redox regulation in hypertension and cardiovascular disease. Nrf2 mediates transcriptional regulation of a variety of target genes. The Keap1-Nrf2-ARE system regulates many detoxification and antioxidant enzymes in cells after the exposure to reactive oxygen species and electrophiles. Activation of Nrf2/ARE signaling is differentially regulated during acute and chronic stress. Keap1 normally maintains Nrf2 in the cytosol and stimulates its degradation through ubiquitination. During acute oxidative stress, oxidized molecules modify the interaction of Nrf2 and Keap1, when Nrf2 is released from the cytoplasm into the nucleus where it binds to the antioxidant response element (ARE). This triggers the expression of antioxidant and detoxification genes. The consequence of long-term chronic oxidative stress is activation of glycogen synthase kinase 3beta (GSK-3beta) inhibiting Nrf2 activity and function. PPARgamma (peroxisome proliferator-activated receptor gamma) is a nuclear receptor playing an important role in the management of cardiovascular diseases, hypertension and metabolic syndrome. PPARgamma targeting of genes with peroxisome proliferator response element (PPRE) has led to the identification of several genes involved in lipid metabolism or oxidative stress. PPARgamma stimulation is triggered by endogenous and exogenous ligands - agonists and it is involved in the activation of several cellular signaling pathways involved in oxidative stress response, such as the PI3K/Akt/NOS pathway. Nrf2 and PPARgamma are linked together with their several activators and Nrf2/ARE and PPARgamma/PPRE pathways can control several types of diseases.

• MeSH
• antioxidační responzivní elementy MeSH
• faktor 2 související s NF-E2 metabolismus   MeSH
• hypertenze metabolismus   patofyziologie   MeSH
• kardiovaskulární nemoci metabolismus   patofyziologie   MeSH
• KEAP-1 metabolismus   MeSH
• krevní tlak * MeSH
• lidé MeSH
• oxidační stres * MeSH
• PPAR gama metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• faktor 2 související s NF-E2 MeSH
• KEAP-1 MeSH
• PPAR gama MeSH
• reaktivní formy kyslíku MeSH

It is now accepted that reactive oxygen species (ROS) are not only dangerous oxidative agents but also chemical mediators of the redox cell signaling and innate immune response. A central role in ROS-controlled production is played by the NADPH oxidases (NOXs), a group of seven membrane-bound enzymes (NOX1-5 and DUOX1-2) whose unique function is to produce ROS. Here, we describe the regulation of NOX5, a widespread family member present in cyanobacteria, protists, plants, fungi, and the animal kingdom. We show that the calmodulin-like regulatory EF-domain of NOX5 is partially unfolded and detached from the rest of the protein in the absence of calcium. In the presence of calcium, the C-terminal lobe of the EF-domain acquires an ordered and more compact structure that enables its binding to the enzyme dehydrogenase (DH) domain. Our spectroscopic and mutagenesis studies further identified a set of conserved aspartate residues in the DH domain that are essential for NOX5 activation. Altogether, our work shows that calcium induces an unfolded-to-folded transition of the EF-domain that promotes direct interaction with a conserved regulatory region, resulting in NOX5 activation.

• Klíčová slova
• EF-hands, NMR, calcium activation, enzyme, structure,
• MeSH
• konformace proteinů MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• molekulární modely MeSH
• NADPH-oxidasa 5 chemie   genetika   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• sinice enzymologie   MeSH
• vápník metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• NADPH-oxidasa 5 MeSH
• reaktivní formy kyslíku MeSH
• vápník MeSH

Alzheimer's disease (AD) is a neurodegenerative disease that is usually accompanied by aging, increasingly being the most common cause of dementia in the elderly. This disorder is characterized by the accumulation of beta amyloid plaques (Aβ) resulting from impaired amyloid precursor protein (APP) metabolism, together with the formation of neurofibrillary tangles and tau protein hyperphosphorylation. The exacerbated production of reactive oxygen species (ROS) triggers the process called oxidative stress, which increases neuronal cell abnormalities, most often followed by apoptosis, leading to cognitive dysfunction and dementia. In this context, the development of new therapies for the AD treatment is necessary. Antioxidants, for instance, are promising species for prevention and treatment because they are capable of disrupting the radical chain reaction, reducing the production of ROS. These species have also proven to be adjunctive to conventional treatments making them more effective. In this sense, several recently published works have focused their attention on oxidative stress and antioxidant species. Therefore, this review seeks to show the most relevant findings of these studies.

• Klíčová slova
• Alzheimer’s disease, antioxidants, cellular respiration, free radicals, oxidative stress,
• MeSH
• Alzheimerova nemoc farmakoterapie   metabolismus   MeSH
• amyloidní beta-protein chemie   metabolismus   MeSH
• antioxidancia farmakologie   terapeutické užití   MeSH
• fosforylace MeSH
• klinické zkoušky jako téma MeSH
• lidé MeSH
• oxidační stres účinky léků   MeSH
• proteiny tau chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• amyloidní beta-protein MeSH
• antioxidancia MeSH
• proteiny tau MeSH