BACKGROUND H2O2 produced by vaginal lactobacilli is believed to protect against infection, and H2O2-producing lactobacilli inactivate pathogens in vitro in protein-free salt solution. However, cervicovaginal fluid (CVF) and semen have significant H2O2-blocking activity. METHODS We measured the H2O2 concentration of CVF and the H2O2-blocking activity of CVF and semen using fluorescence and in ...

Decomposition of hydrogen peroxide (H2O2 ) at physiological levels was studied in human erythrocytes by means of a recently developed sensitive H2O2 assay. The exponential decay of H2O2 in the presence of purified erythrocyte catalase was followed down to 10(-9) mol/L H2O2 at pH 7.4. H2O2 decomposition by purified erythrocyte glutathione peroxidase (GPO) could be directly observed down to 10(-7...

Mitochondria are often regarded as a major source of reactive oxygen species (ROS) in animal cells, with H2O2 being the predominant ROS released from mitochondria; however, it has been recently demonstrated that energized brain mitochondria may act as stabilizers of H2O2 concentration (Starkov et al. [1]) based on the balance between production and the consumption of H2O2, the later of which is...

this study presents a review on advanced oxidation processes (aop) for simultaneous removal of no and so2. aop is based on using a strong oxidant such as ozone and h2o2 which is able to generate highly reactive intermediates. the pollutant will be oxidized and removed by these intermediates. in recent years, aop has been considered as an effective and attractive technology in the field of flue ...

Mitochondria fulfill a number of biological functions which inherently depend on ATP and O2(-•)/H2O2 production. Both ATP and O2(-•)/H2O2 are generated by electron transfer reactions. ATP is the product of oxidative phosphorylation whereas O2(-•) is generated by singlet electron reduction of di-oxygen (O2). O2(-•) is then rapidly dismutated by superoxide dismutase (SOD) producing H2O2. O2(-•)/H...

Hydrogen peroxide (H2O2) is a natural oxidant produced by aerobic organisms and gives rise to oxidative damage, including DNA mutations, protein inactivation and lipid damage. The genus Mycobacterium utilizes redox sensors and H2O2 scavenging enzymes for the detoxification of H2O2. To date, the precise response to oxidative stress has not been fully elucidated. Here, we compared the effects of ...