CNS Redox Homeostasis and Dysfunction in Neurodegenerative Diseases

Intranasal Lithium Chloride Nanoparticles Inhibit Inflammatory Pyroptosis in Brains and Ameliorate Memory Loss and Depression Behavior in 5xFAD mice

This study compares the changes in lithium concentrations in the brain and blood following the administration of intranasal or oral lithium chloride (LiCl) dissolved in either Ryanodex Formulation Vehicle (RFV) or water, as well as the therapeutic effectiveness and side effects of intranasal versus oral lithium chloride (LiCl) in RFV, and their mechanisms for inhibiting inflammation and pyroptosis in 5xFAD Alzheimer's Disease (AD) mice brains. In comparison to oral LiCl in RFV, intranasal LiCl in RFV decreased lithium blood concentrations but increased brain concentrations and duration, resulting in a significantly higher brain/blood lithium concentration ratio than intranasal LiCl in water or oral LiCl in RFV in young adult mice. Intranasal LiCl in RFV robustly protects both memory loss and depressive behavior in both young and old 5xFAD mice, with no side effects or thyroid/kidney toxicity. In fact, intranasal LiCl in RFV protects against age-dependent kidney function impairment in 5xFAD mice. This lithium mediated neuroprotection was associated with its potent effects on the inhibition of InsP3R-1 Ca 2+ channel receptor increase, ameliorating pathological inflammation and activation of the pyroptosis pathway, and the associated loss of synapse proteins. Intranasal LiCl in RFV could become an effective and potent inhibitor of pathological inflammation/pyroptosis in the CNS and treat both dementia and depression with no or minimal side effects/organ toxicity, particular in AD.

Ionizing radiation induces neurotoxicity in Xenopus laevis embryos through neuroactive ligand-receptor interaction pathway

Ionizing radiation (IR) poses a significant threat to both the natural environment and biological health. Exposure to specific doses of ionizing radiation early in an organism's development can lead to developmental toxicity, particularly neurotoxicity. Through experimentation with Xenopus laevis (X. laevis), we examined the effects of radiation on early developmental stage. Our findings revealed that radiation led to developmental abnormalities and mortality in X. laevis embryos in a dose-dependent manner, disrupting redox homeostasis and inducing cell apoptosis. Additionally, radiation caused neurotoxic effects, resulting in abnormal behavior and neuron damage in the embryos. Further investigation into the underlying mechanisms of radiation-induced neurotoxicity indicated the potential involvement of the neuroactive ligand-receptor interaction pathway, which was supported by RNA-Seq analysis. Validation of gene expression associated with this pathway and analysis of neurotransmitter levels confirmed our hypothesis. In addition, we further validated the important role of this signaling pathway in radiation-induced neurotoxicity through edaravone rescue experiments. This research establishes a valuable model for radiation damage studying and provides some insight into radiation-induced neurotoxicity mechanisms.

The ER Stress Induced in Human Neuroblastoma Cells Can Be Reverted by Lumacaftor, a CFTR Corrector

Most neurodegenerative diseases share a common etiopathogenesis, the accumulation of protein aggregates. An imbalance in homeostasis brought on by the buildup of misfolded proteins within the endoplasmic reticulum (ER) results in ER stress in the cell. Three distinct proteins found in the ER membrane-IRE1α, PERK, and ATF6-control the unfolded protein response (UPR), a signal transduction pathway that is triggered to restore normal physiological conditions. Buildup of misfolded proteins in ER lumen leads to a shunting of GRP78/BiP, thus triggering the UPR. PERK autophosphorylation leads to activation of ATF4, the transcription factor; finally, ATF6 activates the UPR's target genes, including GRP78/Bip. Accordingly, the UPR is a cellular reaction to an ER stress state that, if left unchecked for an extended period, results in apoptosis and irreversible damage. The identification of caspase 4, which is in the ER and is selectively activated by apoptotic stimuli caused by reticular stress, further demonstrated the connection between reticular stress and programed cell death. Moreover, oxidative stress and ER stress are linked. Oxidative stress is brought on by elevated quantities of radical oxygen species, both mitochondrial and cytosolic, that are not under the enzymatic regulation of superoxide dismutases, whose levels fall with increasing stress. Here, we evaluated the activity of Vx-809 (Lumacaftor), a drug used in cystic fibrosis, in SH-SY5Y neuronal cells, in which an ER stress condition was induced by Thapsigargin, to verify whether the drug could improve protein folding, suggesting its possible therapeutic use in proteinopathies, such as neurodegenerative diseases (NDs). Our data show that Vx-809 is involved in the significant reduction in protein produced under ER stress, particularly in the levels of Bip, ATF4, and ATF6 by Western blotting analysis, the reduction in ROS in the cytosol and mitochondria, and the reduction in the activation of the apoptotic pathway, measured by flow cytofluorimetry analysis and in restoring calcium homeostasis.

The research landscape of ferroptosis in neurodegenerative disease: a bibliometric analysis

Background

Ferroptosis, a newly proposed concept of programmed cell death, has garnered significant attention in research across different diseases in the last decade. Despite thorough citation analyses in neuroscience, there is a scarcity of information on ferroptosis research specifically related to neurodegenerative diseases.

Method

The Web of Science Core Collection database retrieved relevant articles and reviews. Data on publications, countries, institutions, authors, journals, citations, and keywords in the included studies were systematically analyzed using Microsoft Excel 2019 and CiteSpace 6.2.R7 software.

Result

A comprehensive analysis and visualization of 563 research papers on ferroptosis in neurodegenerative diseases from 2014 to 2023 revealed emerging research hotspots and trends. The number of annual publications in this field of study has displayed a pattern of stabilization in the early years of the decade, followed by a notable increase in the later years and peaking in 2023 with 196 publications. Regarding publication volume and total citations, notable research contributions were observed from countries, institutions, and authors in North America, Western Europe, and China. Current research endeavors primarily focus on understanding the intervention mechanisms of neurodegenerative diseases through the ferroptosis pathway and exploring and identifying potential therapeutic targets.

Conclusion

The study highlights key areas of interest and emerging trends in ferroptosis research on neurodegenerative diseases, offering valuable insights for further exploration and potential directions for diagnosing and treating such conditions.

Mitochondrial Dysfunction as the Major Basis of Brain Aging

The changes in the properties of three biological events that occur with cerebral aging are discussed. These adverse changes already begin to develop early in mid-life and gradually become more pronounced with senescence. Essentially, they are reflections of the progressive decline in effectiveness of key processes, resulting in the deviation of essential biochemical trajectories to ineffective and ultimately harmful variants of these programs. The emphasis of this review is the major role played by the mitochondria in the transition of these three important processes toward more deleterious variants as brain aging proceeds. The immune system: the shift away from an efficient immune response to a more unfocused, continuing inflammatory condition. Such a state is both ineffective and harmful. Reactive oxygen species are important intracellular signaling systems. Additionally, microglial phagocytic activity utilizing short lived reactive oxygen species contribute to the removal of aberrant or dead cells and bacteria. These processes are transformed into an excessive, untargeted, and persistent generation of pro-oxidant free radicals (oxidative stress). The normal efficient neural transmission is modified to a state of undirected, chronic low-level excitatory activity. Each of these changes is characterized by the occurrence of continuous activity that is inefficient and diffused. The signal/noise ratio of several critical biological events is thus reduced as beneficial responses are gradually replaced by their impaired and deleterious variants.

Age-Dependent Changes in Nrf2/Keap1 and Target Antioxidant Protein Expression Correlate to Lipoxidative Adducts, and Are Modulated by Dietary N-3 LCPUFA in the Hippocampus of Mice

The brain has a high metabolism rate that may generate reactive oxygen and nitrogen species. Consequently, nerve cells require highly efficient antioxidant defenses in order to prevent a condition of deleterious oxidative stress. This is particularly relevant in the hippocampus, a highly complex cerebral area involved in processing superior cognitive functions. Most current evidence points to hippocampal oxidative damage as a causal effect for neurodegenerative disorders, especially Alzheimer's disease. Nuclear factor erythroid-2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) is a master key for the transcriptional regulation of antioxidant and detoxifying systems. It is ubiquitously expressed in brain areas, mainly supporting glial cells. In the present study, we have analyzed the relationships between Nrf2 and Keap1 isoforms in hippocampal tissue in response to aging and dietary long-chain polyunsaturated fatty acids (LCPUFA) supplementation. The possible involvement of lipoxidative and nitrosative by-products in the dynamics of the Nrf2/Keap1 complex was examined though determination of protein adducts, namely malondialdehyde (MDA), 4-hydroxynonenal (HNE), and 3-nitro-tyrosine (NTyr) under basal conditions. The results were correlated to the expression of target proteins heme-oxygenase-1 (HO-1) and glutathione peroxidase 4 (GPx4), whose expressions are known to be regulated by Nrf2/Keap1 signaling activation. All variables in this study were obtained simultaneously from the same preparations, allowing multivariate approaches. The results demonstrate a complex modification of the protein expression patterns together with the formation of adducts in response to aging and diet supplementation. Both parameters exhibited a strong interaction. Noticeably, LCPUFA supplementation to aged animals restored the Nrf2/Keap1/target protein patterns to the status observed in young animals, therefore driving a "rejuvenation" of hippocampal antioxidant defense.

[Tandem mass tag-based quantitative proteomics analysis of plasma and plasma exosomes in Parkinson's disease]

The cardinal clinical features of Parkinson's disease (PD), a common neurodegenerative disease, include the irreversible impairment of movement coordination, such as tremors, gait rigidity, bradykinesia, and hypokinesia. Although various factors are associated with the pathological changes in PD, such as oxidative stress, mitochondrial dysfunction, and neuroinflammation, the availability of treatments to retard PD progression is limited. Therefore, novel biomarkers for PD diagnosis and therapeutic targets are urgently needed. The diagnosis of PD mainly depends on its clinical manifestations and has an error rate of approximately 20%. Studies have shown that α-synuclein (α-syn) levels are significantly increased in the cerebrospinal fluid of patients with PD; however, the invasive nature of lumbar puncture restricts further studies on its clinical applications. Hence, the development of novel peripheral blood markers would be helpful for the early diagnosis of PD. Exosomes are extracellular vesicles (EVs) released by various cell types under physiological and pathophysiological conditions. Because exosomes carry a variety of bioactive molecules, they play a key role in biological processes such as intercellular communication and the immune response. Central nervous system (CNS)-derived exosomes can be detected in the cerebrospinal and peripheral body fluids of patients with PD, and their contents are altered during the disease process, rendering them an attractive biomarker resource. Therefore, a comprehensive and high-throughput investigation of the plasma and its exosomes may enhance our understanding of PD. In this study, we isolated exosomes from plasma using standard differential centrifugation and performed tandem mass tag (TMT)-labeled quantitative proteomic analysis of plasma and plasma exosome samples from healthy individuals and patients with PD using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 724 proteins were quantified in the plasma samples, and 611 proteins were screened from the exosome samples. Among these 611 proteins, 413 were found in the Exosomal Protein Database (Exocarta). Using |log2FC|>0.26 and P-value (P)<0.05 as the cutoff, five upregulated and six downregulated proteins were identified in the plasma samples of the PD group compared with the healthy group. In the plasma exosome samples, compared with the healthy group, the PD group showed six upregulated and seven downregulated proteins. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted based on gene set enrichment analysis (GSEA). GO-cellular component (CC) analysis revealed that plasma-enriched proteins were mainly located in the nucleus whereas plasma exosome-enriched proteins were mainly located in the cytoplasm. According to the GO-molecular function (MF) analysis, the MFs of differentially expressed proteins in the plasma were mainly enriched in RNA, DNA binding, and complement binding. By contrast, the molecular functions of differentially expressed proteins derived from plasma exosomes were enriched in antioxidant activity, oxidoreductase activity, and peroxide acceptor activity. We then analyzed the enriched KEGG pathways of differentially expressed proteins derived from the plasma and plasma exosome samples. The enrichment pathways of differentially expressed proteins in the plasma samples included the lysosome pathway, cellular senescence, and protein processing in the endoplasmic reticulum. By contrast, the enrichment pathways of differentially expressed proteins in the plasma exosome samples included chemokine signaling and cytokine receptor interactions. Finally, we assessed the functions of some exosomal proteins in PD to elucidate their potential for PD diagnosis and treatment. Significant differences were observed between the plasma and plasma exosome protein profiles, and the functions of differentially expressed proteins in plasma exosomes were strongly related to the pathology of PD. Our study provides a reference for identifying the potential biomarkers and therapeutic targets of PD.

Inhibitory effect of Dendrobium officinale polysaccharide on oxidative damage of glial cells in aging mice by regulating gut microbiota

Polysaccharides extracted from Dendrobium officinale have various physiological effects. In this study, we used D-galactose-induced senescent mice as an animal model to investigate the inhibitory effects of Dendrobium officinale polysaccharide (DOP) on oxidative damage in glial cells by attenuating oxidative stress and modulating the gut microbiota. The results showed that DOP significantly alleviated the activation of glial cells, increased the activity of antioxidant enzymes and reduced the MDA content in senescent mice. In addition, DOP reshaped the disordered gut microbiota, decreased the abundance ratio of Firmicutes to Bacteroidetes and increased the abundance of beneficial bacteria Lactobacillus. DOP may reverse the gut microbiota disturbance and alleviate the oxidative damage of glial cells, therefore exert potential neuroprotective effects by modulating gut microbiota.

Selenium supplementation enhanced the expression of selenoproteins in hippocampus and played a neuroprotective role in LPS-induced neuroinflammation

Selenium (Se) is obtained from organic and inorganic selenium food content, which mainly depends on the regional soil selenium content. Selenium deficiency and decreased selenoprotein functions have been shown to associate with the progression of cognitive decline and neurodegenerations including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Selenoproteins are well recognized for their anti-oxidative activities. Given the high oxygen consumption, mammalian brains preferent@ially supplied with Se. Here, we propose a beneficiary role for dietary supplementation of sodium selenite (300 ng per gram of body weight) in ameliorating neuroinflammation induced by bilateral intracerebroventricular injection of 1 μL LPS (1 μg/μL), evidenced by the significantly reduced oxidative stress, downregulated pro-inflammatory cytokines expression, improved integrity of blood-brain barrier, as well as suppressed glial activation and shifted microglial MI/M2 polarization in Se-sup mouse brain. Se intake also reduced neural cell death and significantly improved the cognition in Se-sup mice following LPS challenge. The neuroprotective role for supplementary Se is likely to be ascribed to the overall elevated expression of selenoproteins, especially Selenoprotein P (SELENOP) and Glutathione peroxidase 4 (GPX4), ranking on top of the change in selenoprotein expression hierarchy. The regional hierarchy of Se induced elevation of SELENOP expression was further characterized. The SELENOP expression in the mediodorsal thalamic nucleus, dendric gyrus (DG) and cornu ammonis 3 (CA3) of hippocampus and lateral habenular nucleus was highly sensitive to dietary Se intake.

5-(4-Hydroxy-3-dimethoxybenzylidene)-thiazolidinone improves motor functions and exerts antioxidant potential in hemiparkinsonian rats

Our previous study demonstrated that 5-(4-hydroxy-3-dimethoxybenzylidene)-thiazolidinone (RD-1), one of rhodamine derivatives, significantly improves motor function in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model and could minimize mitochondrial impairment, which is a potential therapeutic target to slow down the dopaminergic neurodegeneration in Parkinson's disease. To further evaluate its therapeutic and antioxidative potential in Parkinson's disease, the current study was designed to explore the effect of RD-1 on hemiparkinsonian rats following unilateral 6-hydroxydopamine lesions. Motor functional behavioral tests, including apomorphine-induced rotational analysis and beam walking tests, were assessed. Our results showed that oral RD-1 administration for 2 weeks alleviated beam walking disability, but not the rotational behavior. Furthermore, compared to the sham group, tyrosine hydroxylase- (TH-) positive neurons in the substantia nigra pars compacta and fibers in the striatum were significantly preserved in the RD-1 treatment group. The abnormal activities of superoxide dismutase, catalase, and glutathione peroxidase and contents of MDA were evidently ameliorated by RD-1, at least partly. We conclude that RD-1 could improve motor functions and alleviate the loss of dopaminergic expression in the nigrostriatal pathway of Parkinson's disease rats, and the protective mechanism of RD-1 against neurodegeneration was possibly via its modulation of antioxidation.

Causative links between ER stress and oxidative damage in a yeast model of human N88S seipinopathy

Seipin is encoded by the gene Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) and FLD1/SEI1 in yeast. The gain-of-function N88S mutation in the BSCL2 gene was identified in a cohort of autosomal dominant motor neuron diseases (MNDs) collectively known as seipinopathies. Previous work has shown that this mutation disrupts N-glycosylation, leading to the formation of inclusion bodies (IBs) and contributing to severe Endoplasmic Reticulum (ER) stress and cell death. In this work, we established a humanized yeast model of N88S seipinopathy that recapitulated the formation of IBs and activation of the unfolded protein response (UPR) observed in mammalian systems. Autophagy and the Hrd1-mediated endoplasmic reticulum-associated degradation (ERAD) were fully functional in cells expressing mutant homomers and WT-mutant heteromers of seipin, discarding the possibility that mutant seipin accumulate due to impaired protein quality control systems. Importantly, the N88S seipin form IBs that appear to induce changes in ER morphology, in association with Kar2 chaperone and the Hsp104 disaggregase. For the first time, we have determined that N88S homo-oligomers expressing cells present reduced viability, decreased antioxidant activity and increased oxidative damage associated with loss of mitochondrial membrane potential, higher reactive oxygen species (ROS) levels and lipid peroxidation. This was correlated with the activation of oxidative stress sensor Yap1. Moreover, activation of ERAD and UPR quality control mechanisms were essential for proper cell growth, and crucial to prevent excessive accumulation of ROS in cells expressing N88S homomers solely. Overall, this study provides new insights into the molecular underpinnings of these rare diseases and offers novel targets for potential pharmacological intervention.

Explicating the publication paradigm by bibliometric approaches: A case of interplay between nanoscience and ferroptosis

Background

Ferroptosis has been widely investigated as an emerging drug target, while its combination with nanoscience provides bourgeoning application prospects. The development of ferroptosis regulating nanomedicines have attracted worldwide attentions in recent years. It would be meaningful to describe the relevant publication paradigm.

Methods

Herein, a bibliometric analysis was performed using the database of Web of Science Core Collection to clarify the publication paradigm. The development of related publications in the last 6 years was described, and the revolutionary trends were figured out. Ultimately, the possible future exploration directions were proposed.

Results

The bibliometric analysis of 327 documents of interest indicated that the main research focus was in multiple fields including Materials science, Science & technology, Chemistry, and Pharmacology & pharmacy. With widely cooperation and strong funding, the researchers from Chinese organizations contributed most of publications, followed with United States and Australia. Cocitation analysis revealed that several original papers reported the key molecular mechanisms of ferroptosis were considered as the foundation for subsequent studies, and some nanomedicines-related documents were taken as examples and discussed. Mining results showed that the mechanism evaluation of ferroptosis regulation therapy for cancer treatment was the hotspot. Then, several possible future explorations of ferroptosis-related nanoscience were presented and discussed.

Conclusions

The bibliometric profile of nanoscience-ferroptosis research was analyzed in detail. We believe that the bibliometric analysis could act as a robust method for explicating the publication paradigm as a certain field.

Biochemical regulatory processes in the control of oxidants and antioxidants production in the brain of rats with iron and copper chronic overloads

Iron [Fe(II)] and copper [Cu(II)] overloads in rat brain are associated with oxidative stress and damage. The purpose of this research is to study whether brain antioxidant enzymes are involved in the control of intracellular redox homeostasis in the brain of rats male Sprague-Dawley rats (80-90 g) that received drinking water supplemented with either 1.0 g/L of ferrous chloride (n = 24) or 0.5 g/L cupric sulfate (n = 24) for 42 days. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione transferase (GT) activities in brain were determined by spectrophotometric methods and NO production by the content of nitrite concentration in the organ. Chronic treatment with Fe(II) and Cu(II) led to a significant decrease of nitrite content and SOD activity in brain. Activity of NADPH oxidase increased with Cu(II) treatment. Concerning Fe(II), catalase and GT activities increased in brain after 28 and 4 days of treatment, respectively. In the case of Cu(II), catalase activity decreased whereas GT activity increased after 2 and 14 days, respectively. The regulation of redox homeostasis in brain involves changes of the activity of these enzymes to control the steady state of oxidant species related to redox signaling pathways upon Cu and Fe overload. NO may serve to detoxify cells from superoxide anion and hydrogen peroxide with the concomitant formation of peroxynitrite. However, the latest is a powerful oxidant which leads to oxidative modifications of biomolecules. These results suggest a common pathway to oxidative stress and damage in brain for Cu(II) and Fe(II).

Oxidative Stress, Neuroinflammation and Neurodegeneration: The Chicken, the Egg and the Dinosaur

Neurodegenerative diseases are characterized by the progressive degeneration of the neuronal cells and their networks, hampering the function of the central or peripheral nervous system [...].

The Hidden Notes of Redox Balance in Neurodegenerative Diseases

Reactive oxygen species (ROS) are versatile molecules that, even if produced in the background of many biological processes and responses, possess pleiotropic roles categorized in two interactive yet opposite domains. In particular, ROS can either function as signaling molecules that shape physiological cell functions, or act as deleterious end products of unbalanced redox reactions. Indeed, cellular redox status needs to be tightly regulated to ensure proper cellular functioning, and either excessive ROS accumulation or the dysfunction of antioxidant systems can perturb the redox homeostasis, leading to supraphysiological concentrations of ROS and potentially harmful outcomes. Therefore, whether ROS would act as signaling molecules or as detrimental factors strictly relies on a dynamic equilibrium between free radical production and scavenging resources. Of notice, the mammalian brain is particularly vulnerable to ROS-mediated toxicity, because it possesses relatively poor antioxidant defenses to cope with the redox burden imposed by the elevated oxygen consumption rate and metabolic activity. Many features of neurodegenerative diseases can in fact be traced back to causes of oxidative stress, which may influence both the onset and progression of brain demise. This review focuses on the description of the dual roles of ROS as double-edge sword in both physiological and pathological settings, with reference to Alzheimer's and Parkinson's diseases.

Ergothioneine and central nervous system diseases

Ergothioneine (ERGO) is a thiol contained in the food that exhibits an excellent antioxidant effect similar to that of glutathione. Although mammals lack a biosynthetic pathway for ERGO, the carnitine/organic cation transporter OCTN1/SLC22A4, which transports ERGO in vivo, is expressed throughout the body, and ERGO is distributed to various organs after oral intake. ERGO is a stable compound that remains in the body for a long time after ingestion. OCTN1 is also expressed in brain parenchymal cells, including neurons, and ERGO in the blood permeates the blood-brain barrier and is distributed to the brain, exhibiting a neuroprotective effect. Recently, the association between central nervous system (CNS) diseases and ERGO has become a research focus. ERGO concentrations in the blood components are lower in patients with cognitive impairment, Parkinson's disease, and frailty than in healthy subjects. ERGO exerts a protective effect against various neurotoxins and improves the symptoms of cognitive impairment, depression, and epilepsy in animal models. The promotion of neurogenesis and induction of neurotrophic factors, in addition to the antioxidant and anti-inflammatory effects, may be involved in the neuroprotective effect of ERGO. This review shows the association between ERGO and CNS diseases, discusses the possible biomarkers of peripheral ERGO in CNS diseases, and the possible preventive and improvement effects of ERGO on CNS diseases.

Antioxidant and Neuroprotective Effects of Carnosine: Therapeutic Implications in Neurodegenerative Diseases

Neurodegenerative diseases (NDs) constitute a global challenge to human health and an important social and economic burden worldwide, mainly due to their growing prevalence in an aging population and to their associated disabilities. Despite their differences at the clinical level, NDs share fundamental pathological mechanisms such as abnormal protein deposition, intracellular Ca²⁺ overload, mitochondrial dysfunction, redox homeostasis imbalance and neuroinflammation. Although important progress is being made in deciphering the mechanisms underlying NDs, the availability of effective therapies is still scarce. Carnosine is a natural endogenous molecule that has been extensively studied during the last years due to its promising beneficial effects for human health. It presents multimodal mechanisms of action, being able to exert antioxidant, anti-inflammatory and anti-aggregate activities, among others. Interestingly, most NDs exhibit oxidative and nitrosative stress, protein aggregation and inflammation as molecular hallmarks. In this review, we discuss the neuroprotective functions of carnosine and its implications as a therapeutic strategy in different NDs. We summarize the existing works that study alterations in carnosine metabolism in Alzheimer’s disease and Parkinson’s disease, the two most common NDs. In addition, we review the beneficial effect that carnosine supplementation presents in models of such diseases as well as in aging-related neurodegeneration.