Synergistic Neuroprotection by Caffeine and Astaxanthin Against CNS-OT

Central nervous system oxygen toxicity (CNS-OT) is a critical concern for Navy divers using closed-circuit rebreathers who are subjected to prolonged exposure to hyperbaric oxygen levels. We explored the potential of specific dietary supplements, caffeine, and astaxanthin, to delay the onset of CNS-OT.

Experiments were conducted using male C57BL/6 mice exposed to pure oxygen at 507 kPa, with latency to tonic-clonic seizures recorded. Mice were orally administered caffeine (1.25, 2.5, or 5 mg/ kg), astaxanthin (8 mg/kg), or a vehicle (water).

Caffeine and astaxanthin significantly extended the latency period to seizure onset (p<0.03). Notably, combining caffeine and astaxanthin (p<0.001 vs. control) provided better protection against CNS-OT than either substance alone.

Our results suggest that administering caffeine and astaxanthin before hyperbaric oxygen exposure delays hyperoxia-induced seizures.