Antioxidant Defense in the Toughest Animals on the Earth: Its Contribution to the Extreme Resistance of Tardigrades.

Tardigrades are unique among animals in their resistance to dehydration, mainly due to anhydrobiosis and tun formation. They are also very resistant to high-energy radiation, low and high temperatures, low and high pressure, and various chemical agents, Interestingly, they are resistant to ionizing radiation both in the hydrated and dehydrated states to a similar extent. They are able to survive in the cosmic space.

Effect of Garlic Extract on the Erythrocyte as a Simple Model Cell.

Garlic is known to have diverse effects on mammalian cells, being cytotoxic, especially to cancer cells, but also protect against oxidative stress. Mammalian erythrocyte is a simple cell devoid of intracellular organelles, protein synthesis ability, and most signaling pathways. Therefore, examination of the effects of garlic on erythrocytes allows for revealing primary events in the cellular action of garlic extract.

Effect of Low Concentration of Nitroxides on SH-SY5Y Cells Transfected with the Tau Protein.

Nitroxides, stable synthetic free radicals, are promising antioxidants, showing many beneficial effects both at the cellular level and in animal studies. However, the cells are usually treated with high millimolar concentrations of nitroxides which are not relevant to the concentrations that could be attained in vivo. This paper aimed to examine the effects of low (≤10 μM) concentrations of three nitroxides, 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO), 4-hydroxy-TEMPO (TEMPOL) and 4-amino-TEMPO (TEMPAMINE), in pure chemical systems and on SH-SY5Y cells transfected with the human tau protein (TAU cells), a model of chronic cellular oxidative stress, and transfected with the empty plasmid (EP cells).

Antioxidant defense of : how does it contribute to extreme radiation resistance?

Purpose: is an extremely radioresistant bacterium characterized by D of 10 kGy, and able to grow luxuriantly under chronic ionizing radiation of 60 Gy/h. The aim of this article is to review the antioxidant system of and its possible role in the unusual resistance of this bacterium to ionizing radiation.

Conclusions: The unusual radiation resistance of has apparently evolved as a side effect of the adaptation of this extremophile to other damaging environmental factors, especially desiccation.

Effect of 6-hydroxydopamine increase the glutathione level in SH-SY5Y human neuroblastoma cells.

Treatment of human neuroblastoma SH-SY5Y cells with a catecholaminergic neurotoxin, 6-hydroxydopamine (6-OHDA) is an acknowledged in vitro experimental model of Parkinson disease (PD). A decrease in the glutathione content occurs in PD. Higher concentrations of 6-OHDA lowered the glutathione level in SH-SY5Y cells, nonetheless, we and other authors found a considerable increase in these cells' glutathione content after 24 h treatment with 60 μM 6-OHDA.

Formation of a Purple Product upon the Reaction of ABTS Radicals with Proteins.

The reaction of the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) free radical (ABTS) with proteins (bovine serum albumin, blood plasma, egg white, erythrocyte membranes, and Bacto Peptone) leads not only to a reduction of ABTS but also to the appearance of a purple color (absorption maximum at 550-560 nm). The aim of this study was to characterize the formation and explain the nature of the product responsible for the appearance of this color. The purple color co-precipitated with protein, and was diminished by reducing agents.

Peroxiredoxin 2: An Important Element of the Antioxidant Defense of the Erythrocyte.

Peroxiredoxin 2 (Prdx2) is the third most abundant erythrocyte protein. It was known previously as calpromotin since its binding to the membrane stimulates the calcium-dependent potassium channel. Prdx2 is present mostly in cytosol in the form of non-covalent dimers but may associate into doughnut-like decamers and other oligomers.

Phenolic compounds interfere in the Ampliflu Red/peroxidase assay for hydrogen peroxide.

Methods employing horseradish peroxidase (HRP) are popular for quantification of hydrogen peroxide. This communication reports interference of the Ampliflu Red-HRP assay by phenolic compounds, abundant in food and beverages of plant origin. Concentrations of catechin, propyl gallate, quercetin and gallic acid lowering the yield of the product, resorufin, in this system by 50% were lower than 10 μM.

Capsaicin toxicity to the yeast Saccharomyces cerevisiae is not due to oxidative stress but to disruption of membrane structure.

Capsaicin (CAP) is a common food constituent, conferring a pungent taste to red peppers of the genus Capsicum. It has bactericidal and fungicidal activity. The study was aimed to test the hypothesis of whether oxidative stress mediates the toxicity of CAP to the baker's yeast Saccharomyces cerevisiae as a model yeast.

Induction of Oxidative Stress in SH-SY5Y Cells by Overexpression of hTau40 and Its Mitigation by Redox-Active Nanoparticles.

Abnormally phosphorylated tau protein is the principal component of neurofibrillary tangles, accumulating in the brain in many neurodegenerative diseases, including Alzheimer's disease. The aim of this study was to examine whether overexpression of tau protein leads to changes in the redox status of human neuroblastoma SH-SY5Y cells. The level of reactive oxygen species (ROS) was elevated in tau-overexpressing cells (TAU cells) as compared with cells transfected with the empty vector (EP cells).

Hydrogen peroxide is formed upon cooking of vegetables.

Hydrogen peroxide (H2O2) is generated under autoxidation of some components of beverages including flavonoids and ascorbate, especially in tea and coffee. As polyphenols are also present in solid food, especially in vegetables, we checked whether hydrogen peroxide is generated during cooking of several common vegetables. The formation of hydrogen peroxide was found in the decoctions of all cooked vegetables studied except for potato and in the homogenates of cooked vegetables except for garlic and purple potato.

Antioxidant properties of hispidulin.

There are conflicting reports on the antioxidant activity of hispidulin. Antioxidant activity of hispidulin was evaluated using assays of ABTS reduction, ferric ion reducing antioxidant power (FRAP) assay, DPPH reduction assay, and protection of erythrocyte membranes against lipid peroxidation and protein thiol oxidation. ABTS reduction assay pointed to the involvement of all three phenol groups of hispidulin in ABTS reduction.

Comparison of the Effects of Resveratrol and Its Derivatives on the Radiation Response of MCF-7 Breast Cancer Cells.

Radiotherapy is among the most important methods for breast cancer treatment. However, this method's effectiveness is limited by radioresistance. The aim of this study was to investigate whether the stilbene derivatives piceid, resveratrol, and piceatannol have a radiosensitising effect on breast cancer cells (MCF-7).

The Potential Effects of Phytoestrogens: The Role in Neuroprotection.

Phytoestrogens are naturally occurring non-steroidal phenolic plant compounds. Their structure is similar to 17-β-estradiol, the main female sex hormone. This review offers a concise summary of the current literature on several potential health benefits of phytoestrogens, mainly their neuroprotective effect.

Biological Properties and Applications of Betalains.

Betalains are water-soluble pigments present in vacuoles of plants of the order and in mushrooms of the genera , and . Betalamic acid is a constituent of all betalains. The type of betalamic acid substituent determines the class of betalains.

pH-Responsive Redox Nanoparticles Protect SH-SY5Y Cells at Lowered pH in a Cellular Model of Parkinson's Disease.

The damage to SH-SY5Y cells by 6-hydroxydopamine (6-OHDA) is an established cellular model of Parkinson's disease (PD). Redox nanoparticles are a promising tool for therapy, including neurodegenerative diseases. As pH of the brain tissue at sites affected by PD is lowered down to 6.

The Antiaggregative and Antiamyloidogenic Properties of Nanoparticles: A Promising Tool for the Treatment and Diagnostics of Neurodegenerative Diseases.

Due to the progressive aging of the society, the prevalence and socioeconomic burden of neurodegenerative diseases are predicted to rise. The most common neurodegenerative disorders nowadays, such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis, can be classified as proteinopathies. They can be either synucleinopathies, amyloidopathies, tauopathies, or TDP-43-related proteinopathies; thus, nanoparticles with a potential ability to inhibit pathological protein aggregation and/or degrade already existing aggregates can be a promising approach in the treatment of neurodegenerative diseases.