Reduction of side effects of hyperbaric oxygen therapy with thymoquinone treatment in rats.

Hyperbaric oxygen (HBO₂) treatment results in elevated production of reactive oxygen species (ROS) that leads to cellular damage. Thymoquinone (TQ) is reported to have anti-inflammatory and antimicrobial activity and may suppress the generation of free radicals. The goal of this study is reduction of side effects of hyperbaric oxygen therapy with thymoquinone treatment. 30 female Sprague-Dawley rats were randomly assigned to one of three groups (n = 10 per group). Group 1 represented the control group (no treatment). Group 2 was exposed to 100% oxygen at 2.5 ATA for two sessions of two hours'duration each day for five days. Group 3 was treated identically to Group 2 and was also given thymoquinone once daily at 50 mg/kg/day by oral gavage for five days, after first session of HBO₂. LOOH and SH levels were significantly elevated in the group receiving HBO₂ treatment relative to the control group rats. Fetuin A is increased during TQ treatment. LOOH and SH levels were significantly decreased in animals treated with TQ. Long-term and repeated HBO₂ treatment leads to damage to the lung tissue. In urgent situations or cases of severe hypoxia, repeated HBO₂ sessions may be necessary, and TQ antioxidant agents may be useful for prevention of HBO₂-associated injury. TQ may represent a useful therapeutic option during HBO₂ treatment.