Abstract

Ozone-autohemotherapy (O₃-AHT) has recently gained interest as a form of alternative and complementary medicine. There is, however, some concern regarding its toxicity and effectiveness. Ozone is a powerful oxidant and when introduced into biological fluids react with most cellular components including proteins, lipids and DNA. We assessed the effect of O₃-AHT on peripheral blood mononuclear cells (PBMC) viability, apoptosis and mitochondrial function in the presence and absence of plasma antioxidants. Exposure to ozone increased lactate dehydrogenase (LDH) release and caspase 3/7 activity in PBMC. A decrease in mitochondrial function was measured as a decrease in ATP levels and an increase in NADH/ NAD⁺ ratio. Complex IV (cytochrome c oxidase) of the respiratory chain was almost completely inhibited by ozone. These results indicated that the death of PBMC was probably through apoptosis. These effects were more evident in the absence of plasma antioxidants.  Therefore, high concentrations of ozone were damaging to the cells, but this effect was diminished by antioxidants present in plasma. It is not certain if the in vitro damage will be propagated when ozonated blood is injected back into individuals. One must bear in mind that only a fraction of the total blood volume is ozonated.

Key words: O₃-AHT, alternative medicine, oxidative stress, mitochondrial function, apoptosis.

Abbreviation

O₃-AHT, ozone autohemotherapy; PBMC, peripheral blood mononuclear cells; LDH, lactate dehydro-genase; NADH, nicotinamide adenine dinucleotide (reduced form); NAD⁺, nicotinamide adenine dinucleotide (oxidised form); ROS, reactive oxygen species.