High Resolution ^1H NMR investigations of the
oxidative consumption of salivary biomolecules by ozone: Relevance to the
therapeutic applications of this agent in clinical dentistry
Issue title: Free Radicals in Biology and Medicine: From
Inflammation to Biotechnology
Affiliations: Department of Applied Science, London South Bank
University, UK | Department of Restorative Dentistry, School of
Dentistry, Queen's University, Belfast, Northern Ireland, UK
Note: [] Address for correspondence: Dr. M. Grootveld, Department of
Applied Science, London South Bank University, 103 Borough Road, London SE1
0AA, UK. Tel.: +44 20 7815 7922; Fax: +44 20 7815 7999; E-mail:
[email protected]
Abstract: High resolution proton (^{1}H) nuclear magnetic
resonance (NMR) spectroscopy was employed to simultaneously evaluate the
oxidising actions of ozone (O_{3}) towards a wide range of
salivary biomolecules in view of its applications in dental practices, which
may serve as a viable and convenient means for the treatment of dental caries.
Treatment of supernatants derived from unstimulated human saliva specimens
(n=12) with O_{3} (4.48 mmol) revealed that this reactive
oxygen species gave rise to the oxidative consumption of pyruvate (generating
acetate and CO_{2} as products), lactate (to pyruvate and
sequentially acetate and CO_{2}), carbohydrates in general
(a process generating formate), methionine (giving rise to its corresponding
sulphoxide), and urate (to allantoin). Further, minor
O_{3}-induced modifications included the oxidation of
trimethylamine and 3-D-hydroxybutyrate, the fragmentation of salivary
glycosaminoglycans to NMR-detectable saccharide fragments, and the conversion
of polyunsaturated fatty acids to their ozonides. Moreover, evidence for the
ability of O_{3} to induce the release of selected
low-molecular-mass salivary biomolecules from macromolecular binding-sites was
also obtained. Since many of the oxidation products detectable in
O_{3}-treated samples are identical to those arising from
the attack of ^{•}OH radical on biofluid components,
it appears that at least some of the modifications observed here are
attributable to the latter oxidant (derived from
O_{3}^{•-} generated from the single electron
reduction of O_{3}).
