Do neutrophils produce ozone? An appraisal of current evidence

Recently, it was proposed that neutrophils generate ozone. Evidence for the proposal is based largely on three experimental systems using probes that are known to react with ozone. However, further assessment of the findings shows that in each case, there is a plausible alternative explanation. Oxidation of indigo carmine to isatin sulfonic can be accounted for by superoxide. Conversion of vinylbenzoic acid to p-carboxybenzaldehyde is analogous to the reactions of other styrene derivatives shown to be catalyzed by myeloperoxidase, and more rigorous assessment of alternative explanations is needed before the formation of secosterol oxidation products of cholesterol can be taken as proof of ozone production. We conclude that the evidence for ozone production by neutrophils is not convincing and studies using the same probes to implicate ozone in other biological processes should also be interpreted with caution.