Nicotinamide Improves Functional Recovery via Regulation of the RAGE/JNK/NF-kappa B Signaling Pathway after Brain Injury

Abstract

Brain injuries are a serious global health issue and are the leading cause of neurodegeneration. To date, there is no proper cure and treatment for brain-injury-induced neuropathological conditions because of a lack of sufficient knowledge and the failure to develop a drug due to the multi-pathological conditions in the brain. Herein, we explored the neurotherapeutic effects of Nicotinamide (NAM), against brain injury-induced neurodegeneration and behavioral problems. Treating injured mouse brains with NAM, for 7 days, significantly ameliorated several pathological events. Interestingly, NAM treatment significantly inhibited the injury-induced activation of receptor for advanced glycation end-products (RAGE), c-Jun N-terminal kinases (JNK), and neuroinflammatory mediators, such as NF-kappa B, TNF-alpha, IL-1 beta, and NOS2 in the brain, and it also regulated the levels of apoptotic markers, including Bax, caspase-3, and Bcl-2. Furthermore, treatment using NAM in TBI mice, significantly reversed synaptic protein loss and improved memory impairments and behavioral outcomes. Our findings suggested that NAM treatment reduced injury-induced secondary neurodegenerative pathology by modulating RAGE/JNK/NF-kappa B signaling in mice. Therefore, we recommend that NAM would be a safe and efficient therapeutic agent against brain-injury-induced neurodegeneration.