DNA integrity in patients undergoing hyperbaric oxygen (HBO) therapy.

Hyperbaric oxygen (HBO) therapy is successfully applied for a wide variety of diseases. However, recent studies in humans undergoing (HBO) therapy have revealed that HBO is able to induce oxidative DNA damage especially in lymphocytes while the biological significance of this outcome is still not clear. HBO mediated DNA damage in lymphocytes has been determined by using the alkaline version of the comet assay in order to detect DNA strand breakages in patients undergoing HBO therapy. Blood samples were obtained from 100 voluntary patients and were drawn by venipuncture before and immediately after the first session of HBO treatment. The DNA damaging effect of HBO has also been evaluated in the fifth session of HBO therapy. DNA strand breakages were significantly increased after the first session of HBO treatment. However the elevated DNA strand breaks returned to their normal levels in lymphocytes after two hours of in vitro incubation. The elevated DNA strand breaks consistently decreased and reached to the baseline levels after the fifth session of HBO therapy. The results of this study, conducted in patients undergoing HBO therapy, support the existence of the previously reported cellular adaptive response against HBO mediated oxidative DNA damage in experimental studies.