DL-homocysteine
DL-homocysteine
Overview
DL-homocysteine is the racemic form of homocysteine, a sulfur-containing amino acid that occupies a central position in one-carbon metabolism and the methionine cycle. In biomedical research, homocysteine is widely treated as a clinically relevant metabolite because its circulating concentration can reflect disruptions in Folate and vitamin B12-dependent pathways, altered methylation capacity, and broader metabolic stress. Elevated homocysteine has been associated in recent studies with cognitive decline, neuronal injury, endocrine-metabolic dysregulation, and other disease states.
Although DL-homocysteine itself is a chemical entity rather than a drug, it is frequently studied as a biomarker and mechanistic target in relation to diseases such as Alzheimer's disease, autism spectrum disorder with TORCH-related central nervous system injury, hepatocellular carcinoma, and vitamin B12 deficiency states. Its biological significance lies in its integration with methionine, Folate, and DNA methylation biology, as well as its use as a measurable indicator of metabolic imbalance.
Focus of Latest Publications
Recent publications have used homocysteine as a target analyte or clinical biomarker across several disease contexts. In Alzheimer's disease research, methionine, homocysteine, and methylation levels were examined as predictors of cognitive decline. The study context indicates that homocysteine is part of a metabolic framework involving methionine and DNA methylation in the pathogenesis of Alzheimer's disease, with lower Folate and vitamin B12 and higher homocysteine associated with increased cognitive impairment risk. Related work in the Hubei Memory and Aging Cohort Study also linked higher Hcy, along with higher NFL and GFAP, to increased cognitive impairment risk, while lower Folate, vitamin B12, and hemoglobin were associated with worse outcomes. These findings place DL-homocysteine within a broader biochemical network that includes Beta amyloid, cognitive function, and Serum glial fibrillary acidic protein.
In pediatric neurodevelopmental research, children with ASD and confirmed TORCH-related central nervous system injury showed significantly elevated serum homocysteine, together with neuron-specific enolase, lactate, and ammonia. The reported interpretation was that these abnormalities reflect neuronal injury, mitochondrial dysfunction, and metabolic dysregulation. This positions homocysteine as part of an integrated biochemical profile of neurologic injury rather than as a disease-specific marker alone.
Homocysteine has also been investigated in oncology-related diagnostics. A capillary-SERS sensor based on aptamer-mediated inhibition of nanozyme catalysis was developed for ultrasensitive detection of homocysteine in serum from hepatocellular carcinoma patients. The study emphasized that early detection and sensitive monitoring of serum homocysteine are crucial for liver cancer screening. In this context, homocysteine served as a measurable serum target, and the work focused on analytical sensitivity rather than disease causality.
In reproductive and endocrine-metabolic research, serum homocysteine was included among endocrine and metabolic parameters assessed in a cohort study of 803 women examining autoimmune modulation of ovarian reserve. It was analyzed alongside 25-hydroxy vitamin D, thyroid-stimulating hormone, dehydroepiandrosterone sulfate, plasminogen activator inhibitor-1, HbA1c, androgen indices, and immune markers including natural killer cell cytotoxicity and T helper cell cytokine ratios. Here, homocysteine functioned as one component of a broader immune-endocrine-metabolic phenotype.
Homocysteine has also been used in clinical case evaluation of vitamin B12-related neurologic disease. In a case of metformin-associated functional vitamin B12 deficiency presenting as subacute combined degeneration, a normal serum vitamin B12 level did not exclude metabolic deficiency; further evaluation revealed substantially elevated homocysteine. This illustrates the role of homocysteine as a functional marker of impaired cobalamin-dependent metabolism, especially in patients exposed to metformin therapy or with neurologic symptoms.
Across these studies, DL-homocysteine is consistently treated as a clinically informative metabolite linked to methylation status, vitamin B12 and Folate biology, and systemic metabolic dysfunction. The recent literature does not suggest a direct pharmaceutical role for the compound; rather, it supports its use as a biomarker and mechanistic readout in neurologic, metabolic, endocrine, and oncologic research.
Key Publications
- Jun Effects of betaine-containing nutrients on homocysteine levels and glucose-lipid metabolism in overweight and obese patients with hyperhomocysteinemia. (Nutricion hospitalaria, 2026, PMID 41960847): "this study aimed to assess the effects of betaine-containing nutrients on the levels of homocysteine (Hcy) and glycolipid metabolism indicators in overweight and obese patients with hyperhomocysteinemia (HHcy)."
- Jun Methionine, Homocysteine, and Methylation Levels Predict Cognitive Decline in Alzheimer's Disease. (CNS neuroscience & therapeutics, 2026, PMID 42201257): "...involves metabolic factors such as homocysteine, methionine, and DNA methylation in its pathogenesis."
- May Biochemical Predictors in the Blood Serum of Children with TORCH Encephalopathy and Autism. (Journal of molecular neuroscience : MN, 2026, PMID 42213276): "children with ASD and confirmed TORCH-related central nervous system injury demonstrated significantly elevated serum levels of neuron-specific enolase (NSE), lactate, ammonia, and homocysteine, reflecting neuronal injury, mitochondrial dysfunction, and metabolic dysregulation."
- May Capillary-SERS sensor based on aptamer-mediated inhibition of nanozyme catalysis for ultrasensitive detection of homocysteine in serum from hepatocellular carcinoma patients. (Analytical methods : advancing methods and applications, 2026, PMID 42065546): "Early detection and sensitive monitoring of homocysteine (Hcy) in serum are crucial for liver cancer screening."
- May Serum homocysteine, hemoglobin, and Alzheimer's biomarkers involved in the relationship of folate and vitamin B12 with cognitive function: Findings from the Hubei Memory and Aging Cohort Study. (Nutrition research (New York, N.Y.), 2026, PMID 41980534): "Lower concentrations of folate, vitamin B12, and Hb, and higher concentrations of Hcy, NFL, and GFAP were associated with increased CI risk."
- May Autoimmune modulation of immune-endocrine-metabolic regulation of ovarian reserve: A cohort study of 803 women. (Journal of autoimmunity, 2026, PMID 41932090): "Serum AMH was assessed together with endocrine and metabolic parameters, including 25-hydroxy vitamin D (VitD), thyroid-stimulating hormone (TSH), dehydroepiandrosterone sulfate (DHEAS), plasminogen activator inhibitor-1 (PAI-1), homocysteine, HbA1c, and androgen indices, as well as peripheral immune markers comprising lymphocyte subsets, natural killer (NK) cell cytotoxicity, and T helper (Th) 1/Th2 cytokine producing Th cell ratios."
- Apr Metformin-Associated Functional Vitamin B12 Deficiency Presenting as Subacute Combined Degeneration in a 57-Year-Old Man With Diabetes Mellitus. (The American journal of case reports, 2026, PMID 42035456): "Despite a normal serum vitamin B12 level, further metabolic evaluation revealed a substantially elevated homocysteine level."