Velio Bocci

The ozone paradox: Ozone is a strong oxidant as well as a medical drug

After five decades characterized by empiricism and several pitfalls, some of the basic mechanisms of action of ozone in pulmonary toxicology and in medicine have been clarified. The present knowledge allows to understand the prolonged inhalation of ozone can be very deleterious first for the lungs and successively for the whole organism. On the other hand, a small ozone dose well calibrated against the potent antioxidant capacity of blood can trigger several useful biochemical mechanisms and reactivate the antioxidant system. In detail, firstly ex vivo and second during the infusion of ozonated blood into the donor, the ozone therapy approach involves blood cells and the endothelium, which by transferring the ozone messengers to billions of cells will generate a therapeutic effect. Thus, in spite of a common prejudice, single ozone doses can be therapeutically used in selected human diseases without any toxicity or side effects. Moreover, the versatility and amplitude of beneficial effect of ozone applications have become evident in orthopedics, cutaneous, and mucosal infections as well as in dentistry.

Hypoxia affects cytokine production and proliferative responses by human peripheral mononuclear cells.

We have shown that hypoxia (2% O2 ≈ pO2 14 mmHg) as opposed to O2 atmospheric pressure (20.9% O2 ≈ pO2 140 mmHg) can deeply affect the production of cytokines in human peripheral mononuclear cells (PBMC) in the presence or absence of a specific T‐cell activator such as phytohemagglutinin (PHA). In hypoxia, interleukin (IL)‐2, IL‐4, and interferon (IFN)‐γ production increased by 110, 70, and 50% over that of controls, respectively, in PHA‐stimulated PBMC (P < 0.05). Moreover, in hypoxia, IL‐6 production was significantly enhanced in both resting and PHA‐stimulated PBMC by 36 and 37%, respectively (P < 0.05). However, in hypoxia, IL‐10 production decreased in both resting and stimulated PBMC, being 80 and 67% of controls, respectively (P < 0.05). PBMC proliferation was not significantly affected by hypoxia, although PBMC susceptibility to PHA was about 80% of that of the control (P < 0.05) after 40 hr of treatment, whereas the cycle progression of hypoxic PBMC was delayed. From an evaluation of these results, hypoxia apparently modifies the production of cytokines by PBMC. These results have both theoretical and practical interest because local hypoxia is very common in several conditions, such as inflammation and local ischemia, and is a host‐nonspecific defense against infection. Furthermore, these results suggest a differential pattern of cytokine production in vivo in hypoxic tissues. J. Cell. Physiol. 173:335–342, 1997.

Interleukins : clinical pharmacokinetics and practical implications

Interleukins and tumour necrosis factor (TNF) are a complex group of proteins and glycoproteins able to exert pleiotropic effects with respect to a number of different target cells. In physiological conditions, they are induced and released in basal amounts only in restricted microenvironments where they have paracrine activity. Any small amounts reaching the circulation do not disturb homoeostasis. During therapy, particularly when these cytokines are administered via conventional routes, it has become apparent that their presence in nonphysiological plasma concentrations and their unselective action cause toxic effects with small benefits. The pharmacokinetics of interleukins-1, -2, -3 and -6 and TNF have been evaluated, and their disappearance from plasma after intravenous administration is very rapid (i.e. the distribution half-life is measured in minutes; the elimination half-life is several hours). The efficiency of catabolic pathways such as renal filtration and/or liver uptake is interpreted as a salutary mechanism for extracting proteins that should not be in the circulation. However, because these cytokines are very potent immunomodulatory agents there is a need to improve their therapeutic index, and to this end a number of possible formulations and routes of administration are now available and may eventually be of practical use.

Studies on the biological effects of ozone: 11. Release of factors from human endothelial cells

BACKGROUND: Empirical observations have shown that ozonated autohemotherapy markedly improves the symptoms of chronic limb ischemia (muscular pain at rest, intermittent claudication, etc) in atherosclerotic patients, but mechanisms of action remain unclear. AIMS: Human endothelial cells (HUVECs) are known to release nitrogen monoxide (NO) and we investigated the biological effects of human ozonated serum on HUVECs in culture. METHODS: We assessed the relevance of peroxidation, the release of NO as nitrite and of three classical cytokines. RESULTS: The treatment of HUVECs with ozonated serum yields a dose dependent increase of thiobarbituric acid reactive substances (TBARS) and of hydrogen peroxide (H2O2) and a decrease of protein thiol groups (PTG). Concomitantly, in comparison to either the control or the oxygenated sample, there is a significant and steady increase of nitric oxide (NO) production; this is markedly enhanced by the addition of L-arginine (20 microM) and inhibited in the presence of the NO inhibitor, L-NAME (20 mM). The main mediator of ozone action is H2O2 as it has been shown either after its direct measurement or by the addition of 20, 40 and 100 microM. Moreover, during 24 hours incubation we have investigated the production of endothelin 1 (ET-1), E-selectin and Interleukin 8 (IL-8) and it appears that ozonation enhances IL-8, inhibits E-selectin and hardly modifies ET-1 production. CONCLUSIONS: It appears that reinfusion of ozonated blood, by enhancing release of NO, may induce vasodilation in ischemic areas and reduce hypoxia.

THROMBIN RECEPTOR EXPRESSION AND RESPONSIVENESS OF HUMAN MONOCYTIC CELLS TO THROMBIN IS LINKED TO INTERFERON-INDUCED CELLULAR DIFFERENTIATION

Human thrombin has been shown to stimulate monocyte chemotaxis, phagocytosis, and interleukin (IL8) production, but the mechanisms responsible for stimulation are not well defined. In some cells, thrombin stimulation of proliferation appears to require both cleavage of the proteolytically activated receptor for thrombin (PAR1) and activation of a nonproteolytically activated thrombin receptor (N‐PAR), while in others activation of either receptor alone may be sufficient for stimulation. We, therefore, have initiated studies to address thrombin receptor expression and cell responsiveness to thrombin in interferon gamma (IFNγ)‐differentiated and nondifferentiated U937 monocytic cells. Northern blot analysis shows that PAR1 expression is upregulated upon differentiation. Experiments with biotinylated and 125I‐thrombin show that specific thrombin binding is dramatically increased by differentiation although it is not clear if this binding is to PAR1 or to a separate binding component such as N‐PAR which is present on fibroblasts and other cells. Addition of thrombin at concentrations of 1–10 μg/ml (30–300 nM, concentrations where specific thrombin binding is observed) stimulates proliferation of IFNγ‐differentiated U937 cells but not of undifferentiated U937 cells. Thrombin also stimulates interleukin‐6 (IL6) production in IFNγ‐differentiated U937 cells. Moreover, thrombin induces high levels of IL6, interleukin‐1β (IL1β), and tumor necrosis factor‐α (TNFα) production by peripheral blood mononuclear cells (PBMC) and monocytes. These results show that differentiated U937 cells and mature PBMC are responsive to thrombin whereas nondifferentiated U937 are not. Further, this responsiveness appears to correlate with expression of PAR1 and to a dramatic increase in specific thrombin binding. That thrombin stimulates cytokine production and proliferation in populations of differentiated monocytes suggests that thrombin may be an important regulator of inflammation and wound healing. J. Cell. Physiol. 177:76–84, 1998.

Maternal and Neonatal Plasma Cytokine Levels in Relation to Mode of Delivery

After birth, host defences must be recruited to manage the transition from an almost sterile to a normal environment. The present study was undertaken to evaluate the relationship between cytokine plasma levels and phagocyte burst in mothers and neonates during the peripartal period. Plasma levels of interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and granulocyte-macrophage colony-stimulating factor (GM-CSF) and whole blood superoxide anion (.O2-) generation were evaluated in 27 healthy mothers, 16 undergoing vaginal delivery (VD) and 11 elective caesarean section (ECS) and in their babies. Blood specimens were taken from the mothers at the beginning of labour, during labour, immediately after delivery and 4 days later in the VD group, and before anaesthesia, immediately after delivery and 4 days later in the ECS group; neonatal samples were taken at birth (cord blood) and 4 days later. After delivery by VD, these mothers had higher plasma levels of IL-1 beta, IL-6, IFN-gamma and higher .O2- generation than those delivered by ECS. IL-6 plasma levels and .O2- generation were higher in babies born by VD than in those born by ECS. A statistically significant correlation between IL-6 plasma levels and .O2- release was observed in cord blood of babies born by VD (r = 0.69; p < 0.006). The study demonstrates that labour plays an important role in modulating host defences in the newborn.

Studies on the Biological Effects of Ozone: 10. Release of Factors from Ozonated Human Platelets

In a previous work we have shown that heparin, in the presence of ozone (O3), promotes a dose-dependent platelet aggregation, while after Ca2+ chelation with citrate, platelet aggregation is almost negligible. These results led us to think that aggregation may enhance the release of platelet components. We have here shown that indeed significantly higher amount of platelet-derived growth factor (PDGF), transforming growth factor beta1 (TGF-beta1) and interleukin-8 (IL-8) are released in a dose-dependent manner after ozonation of heparinised platelet-rich plasma samples. These findings may explain the enhanced healing of torpid ulcers in patients with chronic limb ischemia treated with O3 autohaemoteraphy (O3-AHT).

Production and role of interferon in physiological conditions.

1. There is convincing evidence that a number of agents such as bacteria, viruses, endotoxins, foreign proteins, smokes and chemicals come into contact under physiological conditions with the lymphoid tissue associated with the gut and/or bronchial systems. Endogenous lectins and proteases may also act as mitogens on the central and peripheral immune system.

Ozone and Ozonated Oils in Skin Diseases: A Review

Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics.

Ozone acting on human blood yields a hormetic dose-response relationship

The aim of this paper is to analyze why ozone can be medically useful when it dissolves in blood or in other biological fluids. In reviewing a number of clinical studies performed in Peripheral Arterial Diseases (PAD) during the last decades, it has been possible to confirm the long-held view that the inverted U-shaped curve, typical of the hormesis concept, is suitable to represent the therapeutic activity exerted by the so-called ozonated autohemotherapy. The quantitative and qualitative aspects of human blood ozonation have been also critically reviewed in regard to the biological, therapeutic and safety of ozone. It is hoped that this gas, although toxic for the pulmonary system during prolonged inhalation, will be soon recognized as a useful agent in oxidative-stress related diseases, joining other medical gases recently thought to be of therapeutic importance. Finally, the elucidation of the mechanisms of action of ozone as well as the obtained results in PAD may encourage clinical scientists to evaluate ozone therapy in vascular diseases in comparison to the current therapies.