SynthesisFrontiers in immunology2022
Dynamic changes in metabolites of the kynurenine pathway in Alzheimer's disease, Parkinson's disease, and Huntington's disease: A systematic Review and meta-analysis.
Synthesis in Frontiers in immunology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 50 papers, 1 of them a synthesis that pooled it.
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Who cites it
50 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Kynurenine pathway dysregulation in cognitive impairment and dementia: a systematic review and meta-analysis.GeroScience · 2026Pooled it
- The Tryptophan-Kynurenine Pathway as a Key Mediator of the Gut-Brain Axis in Depression and Alzheimer's Disease.International journal of molecular sciences · 2026Review
- Docking Analysis of Drugs Used in the Treatment of Alzheimer's Disease, Using Cell Membrane Receptors and Enzymes of the Kynurenine Pathway: A Pilot Study.International journal of molecular sciences · 2026Article
- Article
- Indole-Derived Compounds as Redox-Modulators: Antioxidant Mechanisms in Neuronal Protection.Molecules (Basel, Switzerland) · 2026Review
- Discovery of the 5-Chlorokynurenine Pathway in Lodopyridone Biosynthesis.Journal of natural products · 2026Article
- Aryl Hydrocarbon Receptor Signaling in Aging: A Key Modulator of Brain Homeostasis.Molecular neurobiology · 2026Review
- Targeted metabolomics to assess positive effects of empagliflozin in a Parkinson's disease model: focused on the kynurenine pathway and oxidative stress.Scientific reports · 2026Article
- Cell Signaling by Tryptophan Catabolism.Biochemistry · 2026Review
- Tryptophan metabolism alterations in neurological and psychiatric diseases: Molecular mechanisms and pharmacological targets.Metabolic brain disease · 2026Review
- Gut Dysbiosis and Microbiota-Derived Metabolites in Neurodegenerative Diseases: Molecular and Biochemical Mechanisms Along the Gut-Brain Axis.Molecules (Basel, Switzerland) · 2026Review
- Synergistic Regulation of Alzheimer's Disease and Intestinal Microbiota Metabolism Mediated by the Gut-Brain Axis: A Comprehensive Analysis from a Multidisciplinary Perspective.International journal of medical sciences · 2026Review
- The kynurenine pathway in depression and schizophrenia: convergent signals, divergent states, and clinical signatures.EXCLI journal · 2026Review
- Kynurenine pathway in Parkinson's disease: pathophysiological roles and therapeutic interventions.Inflammopharmacology · 2026Review
- Kynurenine Pathway Metabolites as Mediators of Exercise-Induced Mood Enhancement, Fatigue Resistance, and Neuroprotection.International journal of molecular sciences · 2025Review
- Metabolomic profiles of depression in Parkinson's disease patients.NPJ Parkinson's disease · 2025Article
- Article
- Interactions between gut microbiota and parkinson's disease: the role of tryptophan metabolism.Cell communication and signaling : CCS · 2025Review
- Emerging strategies, applications and challenges of targeting NADNature aging · 2025Review
- Three Major Deficiency Diseases Harming Mankind (Protein, Retinoid, Iron) Operate Under Tryptophan Dependency.Nutrients · 2025Review
Corrections and comments
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Authors and funding
12 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Background: Tryptophan (TRP) is an essential amino acid that must be provided in the diet. The kynurenine pathway (KP) is the main route of TRP catabolism into nicotinamide adenosine dinucleotide (NAD Objectives: The purpose of this systematic review and meta-analysis is to assess the changes in KP metabolites such as TRP, kynurenine (KYN), kynurenic acid (KYNA), Anthranilic acid (AA), 3-hydroxykynurenine (3-HK), 5-Hydroxyindoleacetic acid (5-HIAA), and 3-Hydroxyanthranilic acid (3-HANA) in Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) patients compared to the control group. Methods: We conducted a literature search using PubMed/Medline, Scopus, Google Scholar, Web of Science, and EMBASE electronic databases to find articles published up to 2022. Studies measuring TRP, KYN, KYNA, AA, 3-HK, 5-HIAA, 3-HANA in AD, PD, or HD patients and controls were identified. Standardized mean differences (SMDs) were used to determine the differences in the levels of the KP metabolites between the two groups. Results: A total of 30 studies compromising 689 patients and 774 controls were included in our meta-analysis. Our results showed that the blood levels of TRP was significantly lower in the AD (SMD=-0.68, 95% CI=-0.97 to -0.40, p=0.000, I2 = 41.8%, k=8, n=382), PD (SMD=-0.77, 95% CI=-1.24 to -0.30, p=0.001, I2 = 74.9%, k=4, n=352), and HD (SMD=-0.90, 95% CI=-1.71 to -0.10, p=0.028, I2 = 91.0%, k=5, n=369) patients compared to the controls. Moreover, the CSF levels of 3-HK in AD patients (p=0.020) and the blood levels of KYN in HD patients (p=0.020) were lower compared with controls. Conclusion: Overall, the findings of this meta-analysis support the hypothesis that the alterations in the KP may be involved in the pathogenesis of AD, PD, and HD. However, additional research is needed to show whether other KP metabolites also vary in AD, PD, and HD patients. So, the metabolites of KP can be used for better diagnosing these diseases.
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