Short term oxidative DNA damage by hyperbaric oxygenation in patients with chronic leg ulcers

Hyperbaric oxygen therapy (HBO) is successfully used for the treatment of a variety of conditions and diseases. HBO therapy can be valuable for treating selected cases of hypoxic diabetic leg ulcers and chronic venous insufficiency. Exposure to high concentration of oxygen is known to induce damage to cells, possibly due to an increased oxygen radical production. Reactive oxygen species also cause DNA damage.

The Comet assay method has been used to determine DNA damage. Number of DNA strand breaks obtained by the single cell gel electrophoresis in nucleuses of lymphocytes was isolated from venous blood. Nucleuses of lymphocytes were incubated by bacterial repair endonucleases, which detect and remove damaged parts of DNA (SBs, FPG, AlcA, ENDO, and H2O2).

27 patients were investigated in this study; diabetes mellitus was diagnosed in 15 of them, and chronic venous insufficiency in 12. They were exposed in average 27 times in a hyperbaric chamber to a pressure of 2.5-3ATA of 100 % oxygen. Lymphocytes were isolated from venous blood before treatment and at different time after treatment (24 hours, 7 days, 14 days, 6 weeks).

Results of DNA damage evaluation at different time periods suggest there are no significant changes if compared to initial DNA damage values. HBO treatment can be used as adjuvant treatment because no significant risk is manifested with this therapy (Tab. 1, Fig. 7, Ref. 52).