REACTIVE OXYGEN SPECIES: THE UNIVERSAL KILLERS?

Diana IVANOVA*,Tatyana YANKOVA*°,Ganka BEKYAROVA**

*Department of Medical Chemistry and Biochemistry, University of Medicine–Varna, 9002, BULGARIA. ** Department of Pathophysiology, University of Medicine-Varna, 9002, BULGARIA.
°Corresponding Author

Summary:
Free radicals are highly reactive species characterised by an unpaired electron in their outer orbital. Oxygen derived free radicals appear in the organism during in physiological and pathological processes. On the other hand they participate in development of many diseases, including rheumatoid arthritis, hemorrhagia, and AIDS in human and animals.There is also evidence that reactive oxygen species (ROS) play a significant role in the pathogenesis of plants. The biological effects of these ROS controlled by antioxidant mechanisms. Overwhelming production of free radicals or deficiences in the antioxidant defences may lead to pathological process.
The production and the activity of ROS as an universal phenomenon for plant and animals as phylogenetically distant organisms and their role in the development of diseases as factors of pathological processes and immune response are discussed in the present paper.

Key words:
Reactive oxygens species, Antioxidant defence, Pathological processes.