Molecular basis of scavenging effect of zonisamide on hydroxyl radical in vitro

Ken-ichi Tanaka, Takeshi Nanba, Tomoyuki Furubayashi, Yasuko Noda, Luther James Willmore, Akitane Mori

Department of Bacteriology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Shikatacho, Japan.
Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Shikatacho, Japan.
Department of Clinical Pharmacy, Shujitsu University School of Pharmacy, Nishigawara, Japan.
Department of Neurology, Saint Louis University School of Medicine, St. Louis, USA.

DOI: 10.4236/jbpc.2012.33030                

Abstract

Zonisamide (ZNS), a commonly used anticonvulsant, scavenged hydroxyl radicals at a clinically relevant concentration. Reactants of ZNS with hydrogen peroxide and with hydrogen peroxide plus UV irradiation, yielding hydroxyl radicals, were analyzed by the LC/MS technique. Many small fragments were found in the both reactions, suggesting that ZNS was decomposed not only by hydroxyl radicals but also by hydrogen peroxide. Furthermore, mass-fragment-grams showed that m/z: 213 (ZNS itself) was decreased markedly and m/z: 118 (may be a decomposed product by ring cleavage of ZNS) was detected specifically by treatment with hydroxyl radical. These data suggested that ZNS may react directly with free radicals.

Keywords

Zonisamide; Hydroxyl Radicals; LC/MS; ESR

Conflicts of Interest

The authors declare no conflicts of interest.

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