Biologically Active Constituents from Salix viminalis Bio-Oil and Their Protective Activity Against Hydrogen Peroxide-Induced Oxidative Stress in Chinese Hamster Ovary Cells

The protective antioxidative effect of the phenolic extract (PE) isolated from Salix viminalis pyrolysis derived bio-oil was shown in vitro on the Chinese hamster ovary (CHO) cells exposed to hydrogen peroxide (H(2)O(2)). Cells pretreated with 0.05 μg/ml PE after exposure to different concentrations of H(2)O(2) (300–900 μM) showed up to 25 % higher viability than the unpretreated ones. The antioxidative effect of PE was also observed in a time-dependent manner. The results were confirmed by visual examination of the specimens using microscopy. Finally, superoxide dismutase (SOD) activity modulation was shown by SOD assay, designed to determine the activity of enzymes removing free radicals

Some aspects of purinergic signaling in the ventricular system of porcine brain

<p>Abstract</p> <p>Background</p> <p>Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system.</p> <p>Results</p> <p>Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (<it>Sus scrofa domestica</it>). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine.</p> <p>Conclusions</p> <p>Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.</p

Purinergic signaling in the pancreas and the therapeutic potential of ecto-nucleotidases in diabetes

It is widely accepted that purinergic signaling is involved in the regulation of functions of all known tissues and organs. Extracellular purines activate two classes of receptors, P1-adenosine receptors and P2-nucleotide receptors, in a concentration-dependent manner. Ecto-enzymes metabolizing nucleotides outside the cell are involved in the termination of the nucleotide signaling pathway through the release of ligands from their receptors. The pancreas is a central organ in nutrient and energy homeostasis with endocrine, exocrine and immunoreactive functions. The disturbances in cellular metabolism in diabetes mellitus lead also to changes in concentrations of intra- and extracellular nucleotides. Purinergic receptors P1 and P2 are present on the pancreatic islet cells as well as on hepatocytes, adipocytes, pancreatic blood vessels and nerves. The ATP-dependent P2X receptor activation on pancreatic β-cells results in a positive autocrine signal and subsequent insulin secretion. Ecto-NTPDases play the key role in regulation of extracellular ATP concentration. These enzymes, in cooperation with 5'-nucleotidase can significantly increase ecto-adenosine concentration. It has been demonstrated that adenosine, through activation of P1 receptors present on adipocytes and pancreatic islets cells, inhibits the release of insulin. Even though we know for 50 years about the regulatory role of nucleotides in the secretion of insulin, an integrated understanding of the involvement of purinergic signaling in pancreas function is still required. This comprehensive review presents our current knowledge about purinergic signaling in physiology and pathology of the pancreas as well as its potential therapeutic relevance in diabetes

Structure and functioning of lysosomal membrane proteins

The lysosomal membrane delimits the interial part of lysosomes containing the enzymes capable of degrading practically all cellular macromolecules, and actively participates as well in establishing an efficient environment for the degradation processes. 1. H+-ATPase - the main membrane protein complex ensures the low pH environment needed for efficient activity of lysosomal hydrolases. 2. Glycoproteins lamp2a are involved in specific degradation of proteins containing the KFERQ sequence (chaperone mediated autophagy) under condition of stress and starvation. 3. Specific lysosomal membrane proteins participate in export from and import to of low molecular weight compounds such as amino acids, dipeptides, sugars, nucleosides, or ions

Non-Thermal Plasma Application in Medicine—Focus on Reactive Species Involvement

Non-thermal plasma (NTP) application in medicine is a dynamically developing interdisciplinary field. Despite the fact that basics of the plasma phenomenon have been known since the 19th century, growing scientific attention has been paid in recent years to the use of plasma in medicine. Three most important plasma-based effects are pivotal for medical applications: (i) inactivation of a broad spectrum of microorganisms, (ii) stimulation of cell proliferation and angiogenesis with lower plasma treatment intensity, and (iii) inactivation of cells by initialization of cell death with higher plasma intensity. In this review, we explain the underlying chemical processes and reactive species involvement during NTP in human (or animal) tissues, as well as in bacteria inactivation, which leads to sterilization and indirectly supports wound healing. In addition, plasma-mediated modifications of medical surfaces, such as surgical instruments or implants, are described. This review focuses on the existing knowledge on NTP-based in vitro and in vivo studies and highlights potential opportunities for the development of novel therapeutic methods. A full understanding of the NTP mechanisms of action is urgently needed for the further development of modern plasma-based medicine

The roles of purinergic signaling in psychiatric disorders

Ecto-purines and ecto-pyrimidines are present in the extracellular space of the central nervous system (CNS). Together with P1 and P2 receptors and nucleotides metabolizing ecto-enzymes, they make signaling system involved in neurotransmission, the modulation of sensory signals, including pain stimuli conduction, and the induction of apoptosis and necrosis of the cells. Purines and pyrimidines have a dual effect: positive (neuroprotective) of nucleosides, and negative (pro-inflammatory and pro-apoptotic) of nucleotides. Adenosine-5'-triphosphate (ATP) in the CNS triggers the pro-inflammatory reactions, predominantly by activation of the P2X7 receptor, which results in production and release of pro-inflammatory cytokines. In contrast to ATP, adenosine acts generally as an anti-inflammatory agent and plays an important role in neuroprotection. Currently, it is believed that the initiation of CNS diseases, including mental disorders, is caused by any imbalance between the concentration of ATP and adenosine in the extracellular space. Genetic tests provide also the evidence for the participation of purinergic signaling in psychiatric disorders. It is believed that any action leading to the effective increase of adenosine concentration: activation of nucleotide metabolizing ecto-enzymes (mainly NTPDases - nucleoside triphosphate diphosphohydrolases), inhibition of adenosine deaminase and/or adenosine kinase activity as well as therapies using P1 receptor agonists (adenosine or its analogues) might be beneficial in therapy of psychiatric disorders

Graphene Oxide-Mediated Protection from Photodamage

This Letter presents the unique properties of graphene oxide (GO) as a multitask material protecting from UVB-induced photodamage. Three mechanisms of GO action on fibroblast in vitro cultures are verified here: physical - a barrier blocking UV radiation; chemical - antioxidative activity; and biological - activation of cellular antioxidative defense. The changes in GO physicochemical properties appearing due to UVB exposure underpin the observed UV protection phenomena. The results reveal the simultaneous occurrence of two opposed processes, i.e., under small doses of UVB, the tested material undergoes oxidation and sp² network rebuilding. In the vicinity of the GO surface, the locally triggered high temperature is responsible for a reduction process, while strong oxidative agents such as OH radicals cause parallel GO oxidation. This phenomenon is enabled thanks to the exceptional properties of carbonaceous materials. As a consequence, GO turns out to be a multitask UV protector increasing fibroblast survival