ChemInform Abstract: PHOTOSENSITIZED OXIDATION OF 1-PHENYLCYCLOBUTENE. THE ROLE OF REACTIVE OXYGEN SPECIES OTHER THAN SINGLET OXYGEN

Reactive oxygen species (ROS), an important molecule inducing oxidative stress in organisms, play a key role in tumorigenesis, tumor progression and recurrence. Recent findings on ROS have shown that ROS can be used to treat cancer as they accelerate the death of tumor cells. At present, pro-oxidant drugs that are intended to increase ROS levels of the tumor cells have been widely used in the clinic. However, ROS are a double-edged sword in the treatment of tumors. High levels of ROS induce not only the death of tumor cells but also oxidative damage to normal cells, especially bone marrow hemopoietic cells, which leads to bone marrow suppression and (or) other side effects, weak efficacy of tumor treatment and even threatening patients’ life. How to enhance the killing effect of ROS on tumor cells while avoiding oxidative damage to the normal cells has become an urgent issue. This study is a review of the latest progress in the role of ROS-mediated programmed death in tumor treatment and prevention and treatment of oxidative damage in bone marrow induced by ROS.

Download Full-text

The Role of Reactive Oxygen Species, Kinases, Hydrogen Sulfide, and Nitric Oxide in the Regulation of Autophagy and Their Impact on Ischemia and Reperfusion Injury in the Heart

Current Cardiology Reviews ◽

10.2174/1573403x16666201014142446 ◽

2020 ◽

Vol 16 ◽

Author(s):

Andrey Krylatov ◽

Leonid Maslov ◽

Sergey Y. Tsibulnikov ◽

Nikita Voronkov ◽

Alla Boshchenko ◽

...

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Hydrogen Sulfide ◽

Ischemia Reperfusion ◽

Reactive Oxygen ◽

Ischemia And Reperfusion ◽

Oxygen Species ◽

Ischemia And Reperfusion Injury ◽

Adaptive Process

: There is considerable evidence in the heart that autophagy in cardiomyocytes is activated by hypoxia/reoxygenation (H/R) or in hearts by ischemia/reperfusion (I/R). Depending upon the experimental model and duration of ischemia, increases in autophagy in this setting maybe beneficial (cardioprotective) or deleterious (exacerbate I/R injury). Aside from the conundrum as to whether or not autophagy is an adaptive process, it is clearly regulated by a number of diverse molecules including reactive oxygen species (ROS), various kinases, hydrogen sulfide (H2S) and nitric oxide (NO). The purpose this review is to address briefly the controversy regarding the role of autophagy in this setting and to examine a variety of disparate molecules that are involved in its regulation.

Download Full-text

Role of Natural Antioxidants on Neuroprotection and Neuroinflammation

Antioxidants ◽

10.3390/antiox10040608 ◽

2021 ◽

Vol 10 (4) ◽

pp. 608

Author(s):

Domenico Nuzzo

Keyword(s):

Reactive Oxygen Species ◽

Energy Metabolism ◽

Respiratory Chain ◽

Reactive Oxygen ◽

Natural Antioxidants ◽

Oxygen Species

All cells continuously generate reactive oxygen species (ROS) through the respiratory chain during the energy metabolism process [...]

Download Full-text

Environmentally persistent free radicals are ubiquitous in wildfire charcoals and remain stable for years

Communications Earth & Environment ◽

10.1038/s43247-021-00138-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Gabriel Sigmund ◽

Cristina Santín ◽

Marc Pignitter ◽

Nathalie Tepe ◽

Stefan H. Doerr ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Free Radicals ◽

Reactive Oxygen ◽

Resonance Spectroscopy ◽

Oxygen Species ◽

Pyrogenic Carbon ◽

Spin Resonance ◽

Long Time ◽

High Concentrations

AbstractGlobally landscape fires produce about 256 Tg of pyrogenic carbon or charcoal each year. The role of charcoal as a source of environmentally persistent free radicals, which are precursors of potentially harmful reactive oxygen species, is poorly constrained. Here, we analyse 60 charcoal samples collected from 10 wildfires, that include crown as well as surface fires in forest, shrubland and grassland spanning different boreal, temperate, subtropical and tropical climate. Using electron spin resonance spectroscopy, we measure high concentrations of environmentally persistent free radicals in charcoal samples, much higher than those found in soils. Concentrations increased with degree of carbonization and woody fuels favoured higher concentrations. Moreover, environmentally persistent free radicals remained stable for an unexpectedly long time of at least 5 years. We suggest that wildfire charcoal is an important global source of environmentally persistent free radicals, and therefore potentially of harmful reactive oxygen species.

Download Full-text