Singlet Oxygen: Scientific Papers

Singlet oxygen: scientific papers and results on the relaxation energy of singlet oxygen

  • Hulten et al. (1999) were able to show that human monocytes in culture produced up to 60 per cent less reactive oxygen species after stimulation with PMA if they had previously been treated with SOE (Singlet Oxygen Energy).
  • Hulten et al. (1999) were able to show that human monocytes in culture produced up to 60 per cent less reactive oxygen species after stimulation with PMA if they had previously been treated with SOE (Singlet Oxygen Energy).
  • SOE (Singlet Oxygen Energy) significantly improves the survival of xeno heart grafts (from hamster to rat). The authors (Lukes et al 2005) suggest that the effect is due to a combination of reduced production of reactive oxygen species and improved oxidative phosphorylation.
  • Orel et al (1997) also report experiences with SOE therapy (Singlet Oxygen Energy) in the treatment of various pathological processes and the reduction of free radicals. Both the photochemically sensitised air and the corresponding drinking water were used (article in Russian, therefore only abstract available)

Production of singlet oxygen in the organism: scientific papers and results on the production of singlet oxygen in the organism

  • In his dissertation, Baier (2005) was able to demonstrate the production of singlet oxygen in living cells for the first time. After excitation with UVA light (355 nm), the active oxygen species could be detected in HT29 and NHEK cell suspensions. L-phosphaditylcholine and flavins, especially the simple flavin, proved to be particularly effective physiological singlet oxygen producers. The lifetime of singlet oxygen in living cultured cells was in the range of 5 µs.
  • Snyder et al. (2005) also concluded in their studies that singlet oxygen lives in the cell (both in the cytoplasm and in the nucleus) one to two orders of magnitude longer than originally thought (originally thought to be 200ns, according to Gorman and Rodgers, 1992).
  • Klotz et al. (2003) and Klotz (2002) describe that singlet oxygen can be formed photochemically or chemically (in a “dark reaction”) in human organisms, for example in phagocytes.
  • Stief (2004) considers chloramines to be the main selective and stable physiological producers of singlet oxygen in the blood. Chloramines are produced together with the oxidant HOCl by activated polymorphonuclear leukocytes.
  • Gillesen et al. (1999) also emphasise the role of chloramines, which are thought to be involved in many biological processes.

Functions of singlet oxygen in the organism: scientific papers and results on the functions of singlet oxygen in the organism

  • Klotz et al. (2003) and Klotz (2002) emphasise that singlet oxygen is not only toxic, but can also trigger a cellular stress response, either through the formation of positive regulators or the inactivation of negative ones. As early as 1997, Briviba et al. pointed out that singlet oxygen can trigger signalling cascades, e.g. the activation of the transcription factor AP-2, c-jun-N-terminal kinases and the NK-kappa B system.
  • There is evidence that oxygen can only bind to haemoglobin in its diamagnetic form, i.e. in the form of singlet oxygen. However, there are two “competing” ideas on the binding of oxygen. One comes from Pauling, the other from R. Weiss. Pauling is of the opinion that oxygen is bound as singlet oxygen in haemoglobin when the oxidation state +II of iron is obtained. According to Weiss, on the other hand, when oxygen is bound, there is an electron transfer between the iron and the oxygen. The iron changes its oxidation state to +III, and the oxygen becomes the negatively charged, radical hyperoxide (superoxide). Today, the “truth” tends to lie somewhere in between (Prof. Rehder, Organic Chemistry, University of Hamburg, personal communication).
  • Snyder et al. (2005) point out that, according to their studies, singlet oxygen is deactivated in the cell primarily by interaction with the solvent (!), less by interactions with cellular components such as proteins. Scientists at the Fraunhofer Institute in Freiburg also point out that singlet oxygen is immediately detoxified in the presence of water.
  • Singlet oxygen is the essential oxidant in the respiratory (oxidative) burst of neutrophils, thus has an essential function in the defence against bacteria and pathogens (Tatsuzawa et al. 1999). It was previously believed that superoxide radicals and hydrogen peroxide were formed during the respiratory burst in studies.
  • Kiryu et al. (1999) show that singlet oxygen is formed in neutrophils under physiological conditions with the involvement of the myeloperoxidase (MPO)-H2O2-Cl(-) system. Zivkovic et al. (2005) have recently shown that neutrophils with their respiratory burst (with formation of singlet oxygen) have antitumour effects in the early phase of tumour development. In COPD patients and asymptomatic smokers, the intracellular respiratory burst of blood leukocytes is reduced (Wehlin et al., 2005)
  • Singlet oxygen modifies important haemostasis factors in human blood (fibrinogen, factor V, factor VIII; factor X) and is thus significantly involved in the regulation of haemostasis (Stief et al., 2000, Stief, 2004). Chloramines appear to be the most important physiological producers of singlet oxygen (Stief, 2004). Other results of Stief’s working group point in the same direction, showing that singlet oxygen dissolves aggregates of platelets (Stief et al. 2001a) and inhibits agonist-induced P-selectin expression and aggregation of platelets (Stief et al., 2001b). Based on these data, Stief hypothesised that singlet oxygen is an antiarteriosclerotic agent.
  • Garvin et al. (2003) describe in a review that reactive oxygen species such as singlet oxygen are important in the regulation of tubular transport in the kidney, which directly affects the regulation of salt and water balance. However, the authors also emphasise that there is little information so far about where and how these regulators act along the nephron.
  • Singlet oxygen has been shown to inactivate free and bound ?2-macroglobulin (and thus the essential broad-spectrum protease inhibitor) in plasma (Stief et al., 2000). The authors suggest that phagocytes release HOCl and chloramines, which in turn leads to the formation of large amounts of singlet oxygen. Singlet oxygen can thus contribute to activating proteases, e.g. at the site of inflammation.
  • Gillesen et al. (1999) emphasise that reactive oxygen species also have a number of physiological functions such as the activation of cellular formation of cytokines and eicosanoids, leukotriene B4, interleukin 8, TNF- á, the activation of adhesion molecules (ICAM-1), arachidonic acid epoxide formation, the release of peptide hormones, the regulation of transcription processes in the cell nucleus and the initiation of increased antioxidant formation (especially SOD).

References: oxygen and singlet oxygen

  • Singlet oxygen 1O2 is the biologically relevant physically excited form of the oxygen molecule. Source: Prof. Erich F. Elstner, Der Sauerstoff, Biochemie, Biologie, Medizin, BI Wissenschaftsverlag, 1990
  • … that oxygen, as an element essential for all aerobes, is very unreactive in its atmospheric form. In order to react with other biomolecules, it must therefore first be activated. Source: Prof. Erich F. Elstner, Oxygen Dependent Diseases and Therapies, BI Wissenschaftsverlag, 1993
  • The general function of membranes is to serve as a permeability barrier for cells and cell organelles…. By cell membranes we mean the bilamellar lipid-protein bilayer that continuously surrounds all cells and is considered the main barrier for the exchange of substances between the cell and its environment. Source: Biophysics, Walter Hoppe, Springer-Verlag, 2nd edition 1982, p 439; p 480
  • The energy balance of a reaction thus stands on an equal footing with its substance balance, whereby a reaction proceeds voluntarily only with the release of energy. Life processes in particular cannot be understood without an insight into the energetics of the reactions involved. Source: Chemie für Mediziner, A. Zeeck, Urban Verlag, 4th edition 2000, p 74