Amounts Of Peroxynitrite Research Articles

Visualization of DNA Damage and Protection by Atomic Force Microscopy in Liquid.

DNA damage is closely related to cancer and many aging-related diseases. Peroxynitrite is a strong oxidant, thus a typical DNA damage agent, and is a major mediator of the inflammation-associated pathogenesis. For the first time, we directly visualized the process of DNA damage by peroxynitrite and DNA protection by ectoine via atomic force microscopy in liquid. We found that the persistence length of DNA decreases significantly by adding a small amount of peroxynitrite, but the observed DNA chains are still intact. Specifically, the persistence length of linear DNA in a low concentration of peroxynitrite (0 µM to 200 µM) solution decreases from about 47 nm to 4 nm. For circular plasmid DNA, we observed the enhanced superhelices of plasmid DNA due to the chain soften. When the concentration of peroxynitrite was above 300 µM, we observed the fragments of DNA. Interestingly, we also identified single-stranded DNAs during the damage process, which is also confirmed by ultraviolet spectroscopy. However, if we added 500 mM ectoine to the high concentration PN solution, almost no DNA fragments due to double strand breaks were observed because of the protection of ectoine. This protection is consistent with the similar effect for DNA damage caused by ionizing radiation and oxygenation. We ascribe DNA protection to the preferential hydration of ectoine.

Analysis of Flavonoid Composition of Korean Herbs in the Family of Compositae and their Utilization for Health

Compositional differences in flavonoids are varied in the big family of Compositae. By summarizing our previous analytical studies and other scientific evidences, new strategy will be possible to further analyze flavonoids and utilize them for human health. The HPLC analytical method has been established in terms of linearity, sensitivity, accuracy, and precision. Herbs of the family of Compositae have considerable amounts of peroxynitrite (ONOO � )-scavenging effects and their phenolic substances. These effects may contribute to the prevention of disease associated with excess production of ONOO � , depending on the high content of flavonoid substances. KeywordsCompositae, Flavonoids, Phenolic substance, HPLC analysis, Peroxynitrite

The Incredible Costs of Chronic Diseases: Why they Occur and Possible Preventions and/or Treatments

The United States government spends 3 trillion dollars on disease treatment each and every year. Chronic diseases are responsible for 86% of these health care costs. Chronic diseases are linked to 70% of the deaths that occur each year. The costs worldwide are likely even greater. After the age of 50, at least 50% of the people from the US have at least one chronic disease. About 1/3 of the US population has some form of diabetes or pre-diabetes. Why does this continue and certainly it is a major factor in the debt of the United States which is approximately 20 trillion dollars. How can the government and our medical people including scientists allow this outrage to continue? Is it because we do not understand the cause of chronic diseases? Certainly we have not developed effective medications and or treatments; so even if we knew what the root cause of chronic diseases could we prevent or reverse them? Dr Peter Barnes, M.D., Ph.D. is the premier scientist in the world who studies acute and chronic lung diseases. He has found that acute diseases can be effectively treated with steroidal anti-inflammatory drugs e.g., asthma; but chronic diseases like chronic obstructive pulmonary disease are not effectively treated with those same steroidal antiinflammatory drugs. The difference between the two diseases forms the blueprint of what causes chronic diseases other than those caused by genetic defects which are relatively rare. The major difference between acute (treatable diseases) and chronic (essentially untreatable or poorly treatable diseases) is the excessive generation of peroxide called peroxynitrite (OONO-). Chronic diseases produce excessive amounts of peroxynitrite and this can create massive biochemical damage to the cell particles (mitochondria) that allow life to continue and produce necessary energy and key enzymatic proteins are damaged as well as the DNA, and RNA-the master molecules of life. Excessive peroxynitrite is the linchpin of chronic diseases. Therefore the key to controlling chronic diseases is to control excessive peroxynitrite. This prevents the damage to our bodies from nitration, nitrosylation and nitrosation all major damages caused by peroxynitrite. How do we control these diseases -we need to find suitable targets of peroxynitrite damage that are non-toxic and exist in a continuous state to fight this toxic chemical. There are peroxynitrite catalytic antagonists and some vitamins like vitamin C and different forms of vitamin E are targets which destroy peroxynitrite and these have been shown to be somewhat effective against chronic diseases. We must introduce the peroxynitrite antagonists early in the disease state before the diseases become irreversible. The excessive peroxynitrite actually damages the epigenetic mechanism (histone deacetylase) by which steroids exert their anti-inflammatory action. But, if we can suppress peroxynitrite early in the chronic disease state -chronic diseases can be become acute and very treatable diseases.

The incredible costs of chronic diseases: Why they occur and possible preventions and/or treatments

The United States government spends 3 trillion dollars on disease treatment each and every year. Chronic diseases are responsible for 86% of these health care costs. Chronic diseases are linked to 70% of the deaths that occur each year. The costs worldwide are likely even greater. After the age of 50, at least 50% of the people from the US have at least one chronic disease. About 1/3 of the US population has some form of diabetes or pre-diabetes. Why does this continue and certainly it is a major factor in the debt of the United States which is approximately 20 trillion dollars. How can the government and our medical people including scientists allow this outrage to continue? Is it because we do not understand the cause of chronic diseases? Certainly we have not developed effective medications and or treatments; so even if we knew what the root cause of chronic diseases could we prevent or reverse them? Dr Peter Barnes, M.D., Ph.D. is the premier scientist in the world who studies acute and chronic lung diseases. He has found that acute diseases can be effectively treated with steroidal anti-inflammatory drugs e.g., asthma; but chronic diseases like chronic obstructive pulmonary disease are not effectively treated with those same steroidal antiinflammatory drugs. The difference between the two diseases forms the blueprint of what causes chronic diseases other than those caused by genetic defects which are relatively rare. The major difference between acute (treatable diseases) and chronic (essentially untreatable or poorly treatable diseases) is the excessive generation of peroxide called peroxynitrite (OONO-). Chronic diseases produce excessive amounts of peroxynitrite and this can create massive biochemical damage to the cell particles (mitochondria) that allow life to continue and produce necessary energy and key enzymatic proteins are damaged as well as the DNA, and RNA-the master molecules of life. Excessive peroxynitrite is the linchpin of chronic diseases. Therefore the key to controlling chronic diseases is to control excessive peroxynitrite. This prevents the damage to our bodies from nitration, nitrosylation and nitrosation all major damages caused by peroxynitrite. How do we control these diseases -we need to find suitable targets of peroxynitrite damage that are non-toxic and exist in a continuous state to fight this toxic chemical. There are peroxynitrite catalytic antagonists and some vitamins like vitamin C and different forms of vitamin E are targets which destroy peroxynitrite and these have been shown to be somewhat effective against chronic diseases. We must introduce the peroxynitrite antagonists early in the disease state before the diseases become irreversible. The excessive peroxynitrite actually damages the epigenetic mechanism (histone deacetylase) by which steroids exert their anti-inflammatory action. But, if we can suppress peroxynitrite early in the chronic disease state -chronic diseases can be become acute and very treatable diseases.

Membrane effect of lidocaine is inhibited by interaction with peroxynitrite

Inflammation is clinically well known to decrease the efficiency of local anesthesia, an effect which has been explained mechanistically by tissue acidosis in the literature. However, recent studies offer no support to such a pharmacopathological background for anesthetic failure. Because inflammatory cells produce significant amounts of peroxynitrite, the peroxynitrite could interact with local anesthetics to decrease their effects. To examine this speculated interaction, we determined whether membrane fluidization, as one mode of local anesthetic action, was influenced by peroxynitrite. The membrane effects were analyzed by measuring the fluorescence polarization of liposomes prepared with 1, 2-dipalmitoylphosphatidylcholine. Although lidocaine, at a clinically relevant concentration, fluidized liposomal membranes, its fluidizing potency was reduced to 43.6 +/- 4.4% and 58.4 +/- 7.5% of that in membranes without peroxynitrite when membranes were pretreated with 50 and 250 microM peroxynitrite, respectively, for 15 min. A significant inhibition of membrane fluidization of 27.5 +/- 6.8%, was also observed after reaction for 5 min. Peroxynitrite released by inflammatory cells may affect local anesthesia through a possible interaction with lidocaine, inhibiting its membrane-fluidizing effect.

Inhibition of SIN-1-induced change in mitochondrial membrane permeability in PC12 cells by dopamine.

Dopamine (50 or 100 microM) attenuated the nuclear damage and cell death due to 500 microM SIN-1, a donor of superoxide and nitric oxide, in differentiated PC12 cells whereas 200 microM dopamine did not depress cell death. Dopamine at 50-100 microM for a 4-h treatment did not show a significant cytotoxic effect on PC12 cells. Dopamine (100 microM) inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, activation of caspase-3, formation of reactive oxygen species, and depletion of glutathione (GSH) due to 500 microM SIN-1 in PC12 cells. The reaction of dopamine with peroxynitrite reduced an amount of peroxynitrite. The results suggest that dopamine exhibits a biphasic effect against the cytotoxicity of SIN-1 depending on concentrations. Dopamine at 50-100 microM may attenuate the reactive nitrogen species-induced viability loss in PC12 cells by suppressing the mitochondrial membrane permeability change through inhibition of the formation of reactive species, including peroxynitrite.

Grand Larceny: Oxidant corrupts protein by filching crucial atom (Oxidative damage; Cardiovascular disease)

A new study reveals how oxidants undermine an enzyme that helps keep our blood vessels open and clear of clots. These molecular vandals steal an atom of zinc that helps hold the protein together--not only harming the enzyme in the process but also stimulating the production of more of the cell-wrecking chemicals. By gnawing on proteins and other molecules, oxidants drive heart disease, diabetes, and aging--or so the theory goes (see "The Two Faces of Oxygen" ). These hungry molecules, such as superoxide and peroxynitrite, are spawned in the normal course of metabolism. How they could wreak so much destruction is an enigma, considering that only 1 in 1000 to 1 in 10,000 amino acids in a cell show signs of oxidative wounds, says Jay Heinecke of Washington University in St. Louis, Missouri, an authority on these baneful molecules. Zou and colleagues uncovered the effects of oxidants on one of the body's key enzymes, nitric oxide synthase, which comprises two identical halves coupled by a bridge containing zinc and sulfur. True to its name, nitric oxide synthase makes nitric oxide, a versatile and vital signaling molecule that opens blood vessels and inhibits clot formation. The researchers exposed nitric oxide synthase to peroxynitrite and tracked the enzyme's response. Even small amounts of peroxynitrite broke the protein in half by swiping zinc from the bridge. The same changes occurred when the researchers treated the enzyme with a molecule that locks up zinc, confirming that the parting of the protein resulted from removing the metal. What's more, cells bathed in abnormally large amounts of glucose and cells from diabetic mice showed the same breakup of nitric oxide synthase--which suggests that damage to the enzyme might contribute to diabetes. Broken nitric oxide synthase doesn't simply fail to produce nitric oxide. Oxidation brings out the enzyme's alter ego, which instead makes superoxide. This promiscuous oxidant can react with nitric oxide to produce yet more peroxynitrite--setting off a runaway process of peroxynitrite formation. Although previous work had suggested that nitric oxide synthase might spawn peroxynitrite, this study is the first to clarify the mechanism and to show how sensitive the enzyme is, even to low concentrations of the oxidant. Both consequences of oxidation might compromise health, says biochemist Ming-Hui Zou of Boston University School of Medicine. Reduced amounts of nitric oxide narrow blood vessels and spur clotting, which worsen cardiovascular disease. Peroxynitrite also attacks a molecule that prevents constriction of blood vessels, which might explain why the arteries of diabetics expand reluctantly, Zou adds. According to Heinecke, the results also back a nontraditional view of how oxidants wreak havoc. The conventional notion--that their attack cripples proteins--is hard to square with the rarity of oxidants in the body's cells. A more plausible idea, says Heinecke, is that oxidants pervert proteins instead of wrecking them: "You are damaging a protein in a way that produces a gain in function. It's doing something bad instead of something good." --Mitch Leslie M.-H. Zou, C. Shi, R. A. Cohen, Oxidation of the zinc-thiolate complex and uncoupling of endothelial nitric oxide synthase by peroxynitrite. J. Clin. Invest. 109 , 817-826 (2002). [Abstract] [Full Text]

Peroxynitrite promotes mitochondrial permeability transition-dependent rapid U937 cell necrosis: Survivors proliferate with kinetics superimposable on those of untreated cells

A short term exposure to peroxynitrite promotes a time- and concentration-dependent lethal response in U937 cells. The mode of cell death was necrosis and rapid (within minutes) cell lysis was found to occur via a mechanism involving mitochondrial permeability transition. Apoptosis was not detected in cells exposed to low levels of peroxynitrite, or in cells which survived a treatment with toxic amounts of peroxynitrite, neither after the 60 min exposure nor following increasing time intervals of growth in fresh culture medium. Rather, cells treated with peroxynitrite concentrations which were not immediately lethal, as well as the survivors of treatments with toxic levels of peroxynitrite, proliferated with kinetics superimposable on those observed in untreated cells.