In vitro Effects of Vitamin E on Hydrogen Peroxide

Abstract Increased in vitro erythrocyte sensitivity to the hemolytic effects of hydrogen peroxide (H2O2) in the H2O2 fragility test has been widely associated with vitamin E deficiency. In the present study, H2O2 red cell fragility was abnormally elevated in many types of acquired and congenital anemias in children who were tocopherol sufficient. In addition to abnormal red cell H2O2 sensitivity known to occur in vitro in conditions involving defects in cellular devices for disposal of peroxides, it is likely that a wide variety of erythrocyte dysfunctions result in increased in vitro H2O2 hemolysis even in situations where the usually adequate mechanisms for peroxide detoxification are present.

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In Situ and In Vitro Effects of Two Bleaching Treatments on Human Enamel Hardness

Brazilian Dental Journal ◽

10.1590/0103-6440201600385 ◽

2016 ◽

Vol 27 (1) ◽

pp. 56-59 ◽

Cited By ~ 7

Author(s):

Sandrina Henn-Donassollo ◽

Cristiane Fabris ◽

Morgana Gagiolla ◽

Ícaro Kerber ◽

Vinícius Caetano ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Oral Appliance ◽

Water Cooling ◽

Surface Microhardness ◽

Tukey Test ◽

Human Enamel ◽

Before And After ◽

In Vitro Effects

Abstract The aim of this study was to evaluate in vitro and in situ the effects of two bleaching treatments on human enamel surface microhardness. Sixty enamel slabs from recently extracted thirty molars were used. The specimens were polished with sandpapers under water-cooling. The enamel samples were randomly divided in four groups, treated with 10% hydrogen peroxide (HP) or Whitening Strips (WS) containing 10% hydrogen peroxide and using two conditions: in vitro or in situ model. For in situ condition, six volunteers wore an intra-oral appliance containing enamel slabs, while for in vitro condition the specimens were kept in deionized water after the bleaching protocols. The bleaching treatments were applied one-hour daily for 14 days. Similar amounts of bleaching agents were used in both conditions. Before and after bleaching treatments, microhardness was measured. Statistical analysis (ANOVA and Tukey test) showed that in the in situ condition there was no statistically significant microhardness reduction in the bleached enamel (p>0.05). Significant decrease in hardness was observed for enamel slabs bleached with both treatments in the in vitro condition (p<0.05). Regarding the bleaching agents, in situ results showed no difference between HP and WS, while in vitro WS produced the lowest hardness value. It could be concluded that there was no deleterious effect on enamel produced by any of the bleaching protocols used in the in situ model. The reduction of hardness was only observed in vitro.

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In Vitro Effects of Certain Membrane-acting Agents on Superoxide and Hydrogen Peroxide Production, Protein Synthesis and Membrane ATPase Activity in Buffalo PMN Cells

Alternatives to Laboratory Animals ◽

10.1177/026119290703500404 ◽

2007 ◽

Vol 35 (4) ◽

pp. 397-404 ◽

Cited By ~ 1

Author(s):

Hemen Das ◽

Golla Ramalinga Reddy ◽

Tukaram More ◽

Vineet Kumar Singh

Keyword(s):

Hydrogen Peroxide ◽

Protein Synthesis ◽

Atpase Activity ◽

Antimicrobial Proteins ◽

Level Of Activity ◽

Membrane Atpases ◽

In Vitro Effects ◽

Reactive Oxidants ◽

Proteins And Peptides

Polymorphonuclear (PMN) cells play a key role in innate immunity, due to their ability to produce reactive oxidants such as superoxide (O2–) and hydrogen peroxide (H2O2), and to release antimicrobial proteins and peptides stored in their lysosomal granules. In the present study, the effects of the activation of buffalo PMN cells with various membrane-acting agents were evaluated in terms of O2– and H2O2 production, the activities of membrane ATPases, and protein synthesis. Studies involving the incorporation of 35S-methionine revealed significant protein-synthesising ability in resting PMN cells and in cells treated with lipopolysaccharide (LPS), as well as with opsonised zymosan (OZ). Protein synthesis, as judged by fluorography of the cytosolic fraction, showed more than 12 bands, whilst the cytoskeletal fraction showed 2–3 bands. PMN activation with concanavalin A (ConA), digitonin and sodium nitroprusside (SNP) resulted in increased O2– and H2O2 production. However, in the presence of anti-inflammatory agents such as indomethacin and cortisol, the production of O2– and H2O2 by these cells was found to decline. Studies pertaining to membrane ATPases revealed that verapamil hydrochloride (VpHCl) significantly increased total ATPase and Na+K+ATPase activity. ConA treatment yielded only a moderate level of activity. Similarly, digitonin up to 24μM also caused a significant increase in ATPase activity. Our observations indicate that these membrane-acting agents influenced oxygen-dependent and oxygen-independent microbicidal mechanisms in buffalo PMN cells.

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