Adjudin, a small molecular compound that is used as a male contraceptive, has been reported to play a neuroprotective role in an ischemic stroke injury model. However, its effect on traumatic brain injury (TBI) has not been assessed. Hence, we investigated the effects of adjudin on cerebral edema using a mouse model of TBI and explored the underlying mechanisms. Adult male C57BL/6 mice received controlled cortical impact (CCI) injury, then an injection of adjudin (50 mg/kg). The mice were euthanized 3 days post-CCI injury, and samples were collected for further analysis. Cultured primary mouse astrocytes were used for in vitro experiments. Adjudin treatment significantly attenuated cerebral edema on Day 3 and improved neurobehavioral outcomes on Days 3, 7, and 14 after CCI injury, compared with the vehicle group. Additionally, the evaluation of Evans blue extravasation and expression of tight junction proteins demonstrated remarkable effects of adjudin on blood-brain barrier protection. Further, adjudin treatment significantly decreased the gene and protein expression of aquaporin 4 in post-injury mice and inhibited progression of neuroinflammation in both mice and cultured astrocytes. The Western blot results of the peritraumatic protein samples demonstrated that adjudin significantly blocked the phosphorylation of IKKα, IκBα/β, and NF-κB p65, which resulted in a reduction of NF-κB p65 nuclear translocation. In conclusion, adjudin attenuated the development of TBI-induced cerebral edema at least partly via anti-inflammatory effects and inhibition of the NF-κB pathway. These findings suggest that adjudin is a potential therapeutic intervention preventing the development of cerebral edema after TBI.
Keywords: AQP4; NF-κB; TBI; adjudin; neuroinflammation.