Natural Dietary Supplementation of Curcumin Protects Mice Brains against Ethanol-Induced Oxidative Stress-Mediated Neurodegeneration and Memory Impairment via Nrf2/TLR4/RAGE Signaling

The aim of the current study was to explore the underlying neuroprotective mechanisms of curcumin (50 mg/kg, for six weeks) against ethanol (5 mg/kg i.p., for six weeks) induced oxidative stress and inflammation-mediated cognitive dysfunction in mice. According to our findings, ethanol triggered reactive oxygen species (ROS), apoptosis, neuroinflammation, and memory impairment, which were significantly inhibited with the administration of curcumin, as assessed by ROS, lipid peroxidation (LPO), and Nrf2/HO-1 (nuclear factor erythroid 2-related factor 2/Heme-oxygenase-1) expression in the experimental mice brains. Moreover, curcumin regulated the expression of the glial cell markers in ethanol-treated mice brains, as analyzed by the relative expression TLR4 (Toll like Receptor 4), RAGE (Receptor for Advanced Glycations End products), GFAP (Glial fibrillary acidic protein), and Iba-1 (Ionized calcium binding adaptor molecule 1), through Western blot and confocal microscopic analysis. Moreover, our results showed that curcumin downregulated the expression of p-JNK (Phospo c-Jun N-Terminal Kinase), p-NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells), and its downstream targets, as assessed by Western blot and confocal microscopic analysis. Finally, the expression of synaptic proteins and the behavioral results also supported the hypothesis that curcumin may inhibit memory dysfunction and behavioral alterations associated with ethanol intoxication. Altogether, to the best of our knowledge, we believe that curcumin may serve as a potential, promising, and cheaply available neuroprotective compound against ethanol-associated neurodegenerative diseases.