Antioxidant properties of Neu2000 on mitochondrial free radicals and oxidative damage

• Published in: Toxicology in vitro 2013-03, Vol.27 (2), p.788-797
• Main Authors: Visavadiya, Nishant P., McEwen, Melanie L., Pandya, Jignesh D., Sullivan, Patrick G., Gwag, Byoung Joo, Springer, Joe E.
• Format: Article
• Language: English
• Subjects: Animals; Antioxidant; Antioxidants - pharmacology; Female; Fluorobenzenes - pharmacology; Free Radicals - metabolism; Glutathione - metabolism; In Vitro Techniques; Iron - metabolism; Lipid peroxidation; meta-Aminobenzoates - pharmacology; Mitochondria; Mitochondria - drug effects; Mitochondria - metabolism; Neu2000; Neuroprotective Agents - pharmacology; Nitric Oxide - metabolism; Oxidative Stress - drug effects; Protein Carbonylation - drug effects; Rats; Rats, Long-Evans; Reactive nitrogen species; Reactive oxygen species; Salicylates - pharmacology; Spinal Cord - metabolism
• ISSN: 0887-2333; 1879-3177
• DOI: 10.1016/j.tiv.2012.12.011

► Neu2000 is a novel therapeutic agent for the treatment of central nervous system disorders. ► This is the first study to identify the IC50 values of Neu2000 on various free radical species. ► Neu2000 strongly scavenged reactive oxygen and nitrogen species (ROS/RNS). ► Neu2000 reduced free radicals and oxidative damage in mitochondria. ► Neu2000 shows a broad spectrum of antioxidant actions. Neu2000 [2-hydroxy-5-(2,3,5,6-tetrafluoro-4 trifluoromethylbenzylamino) benzoic acid] is a dual-acting neuroprotective agent that functions both as a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist and a free radical scavenger. In the present study, we investigated the scavenging activity of Neu2000 on various classes of reactive oxygen species and reactive nitrogen species (ROS/RNS) as well as its efficacy for reducing free radicals and oxidative stress/damage induced in spinal cord mitochondrial preparations. Neu2000 exerted scavenging activity against superoxide, nitric oxide, and hydroxyl radicals, and efficiently scavenged peroxynitrite. In the mitochondrial studies, Neu2000 markedly inhibited ROS/RNS and hydrogen peroxide levels following antimycin treatment. In addition, Neu2000 effectively scavenged hydroxyl radicals generated by iron(III)-ascorbate, reduced protein carbonyl formation mediated by hydroxyl radicals and peroxynitrite, and prevented glutathione oxidation caused by tert-butyl hydroperoxide in isolated mitochondria. Interestingly, incubation of isolated mitochondria with Neu2000 followed by centrifugation and removal of the supernatant also resulted in a concentration-dependent decrease in lipid peroxidation. This observation suggests that Neu2000 enters mitochondria to target free radicals or indirectly affects mitochondrial function in a manner that promotes antioxidant activity. The results of the present study demonstrate that Neu2000 possesses potent in vitro antioxidant activity due, most likely, to its active phenoxy group.