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

Abstract

High resolution proton (1H) nuclear magnetic resonance (NMR) spectroscopy was employed to simultaneously evaluate the oxidising actions of ozone (O3) 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 O3 (4.48 mmol) revealed that this reactive oxygen species gave rise to the oxidative consumption of pyruvate (generating acetate and CO2 as products), lactate (to pyruvate and sequentially acetate and CO2), carbohydrates in general (a process generating formate), methionine (giving rise to its corresponding sulphoxide), and urate (to allantoin). Further, minor O3-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 O3 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 O3-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 O3*- generated from the single electron reduction of O3).