Evaluation of antioxidant activity of emulsan <i>in vitro</i>

• Autores: Castro, Guillermo Raúl; Zuluaga, Natalia; Panilaitis, Bruce; Kaplan, David; Pandey, A.; Larroche, C.; Soccol, C. R.; Dussap, C.-G.
• Año de publicación: 2009
• Idioma: inglés
• Tipo de recurso: parte de libro
• Materia: Química; Estrés Oxidativo; Oxígeno reactivo; Especies de Nitrógeno Reactivo
• Institución: Universidad Nacional de La Plata

Oxidative stress has been involved in the development of several pathologies, including vascular damage associated to myocardial and neurological degeneration, such as arteriosclerosis, cerebral ischemia among others; while diabetes, rheumatoid arthritis, inflammation, cancer-initiation, and acceleration of the aging processes are also reported (Coyle and Puttfarcken, 1993; Margail et al., 2005). The toxicity of oxidative stress is believed to be caused by Reactive Oxygen and Nitrogen Species (ROS and RNS, respectively) that can initiate a wide range of oxidative toxic reactions in biological systems (Cuzzocrea et al., 2001). Typical radicals and radical-related toxic molecules produced by ROS are hydrogen peroxide (H2O2), hydroxyl radical (OH⋅), singlet oxygen (1O2), and superoxide anion radical (O2 ⋅-) (Figure 1). The RNS toxic reactants include nitric oxide (NO⋅) and the most powerful oxidant peroxynitrite anion (ONOO-). Biological antioxidant mechanisms described in the literature are many, but with different efficiencies implicating enzymatic as well as non-enzymatic activities. Some of the most relevant antioxidative biocatalysts are superoxide dismutase, and catalase. In addition, other specialized enzymes such as glutathione peroxidase and ã-glutamylcysteine synthetase can be involved in deactivation mechanisms (Figure 1). Well-known non-enzymatic antioxidants are b-carotene, glutathione, melatonin and vitamins C and E, (Valko et al., 2006). However, excessive and persistent formation of free radicals could be main factors of genotoxic effects.
Trabajo presentado en International Conference on New Horizons in Biotechnology (NHBT-2007) (Trivandrum, India, November 26-29, 2007).
Centro de Investigación y Desarrollo en Fermentaciones Industriales
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas