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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.