Studies on the biological effects of ozone: 8. Effects on the total antioxidant status and on interleukin-8 production

OZONE (O-3) is a Controversial gas because,owing to its potent oxidant prop erties, it exerts damaging effects on the respiratory tract and yet it has been used for four decades as a therapy. While the disinfectant activity of O-3 is understandable, it is less clear how other biological effects can b e elicited in human blood with practically no toxicity. On the other hand p lasma and cells are endowed with a powerful antioxidant system so that a fa irly wide range of O-3 concentrations between 40 and 80 mu g/ml per gram of blood (similar to 0.83-1.66 mM) are effective but not deleterious. After b lood ozonation total antioxidant status (TAS) and plasma protein thiol grou ps (PTG) decrease by 20% and 25%, respectively, while thiobarbituric acid r eactive substances (TBARS) increases up to fivefold. The increase of haemol ysis is negligible suggesting that the erythrocyte membrane is spared at th e expense of other sacrificial substrates. While there is a clear relations hip between the ozone dose and IL-8 levels, we have noticed that high TAS a nd PTG values inhibit the cytokine production. This is in line with the cur rent idea that hydrogen peroxide, as a byproduct of O-3 decomposition, acts as a messenger for the cytokine induction.