Citicoline: A Superior Form of Choline?

Multivariate Modular Metabolic Engineering for the Enhanced Biosynthesis of Cytidine in Bacillus subtilis

As a pyrimidine nucleoside, cytidine is widely used in the medicine and food fields. Therefore, it is important to construct a microbial cell factory for efficient and sustainable cytidine production. Here, we perform modular metabolic engineering modifications on Bacillus subtilis 168 to achieve efficient synthesis of cytidine. First, the cytidine titer reached 0.88 g/L by blocking cytidine degradation and enhancing the cytidine de novo synthesis pathway. Next, the central carbon metabolism was modulated by knocking down CcpA, but the cytidine titer decreased instead. Transcriptome analysis revealed that differential genes were mainly enriched in PTS, glycolysis, TCA cycle, PP pathway, pyrimidine metabolism, aspartate metabolism, and glutamate metabolism. Then, by enhancing the l-aspartate and glutamine synthesis pathways, the cytidine titer was increased to 3.83 g/L. By strengthening the PP pathway to increase PRPP synthesis, the cytidine titer was further increased to 7.03 g/L. Finally, the cytidine titer reached 31.41 g/L by fed-batch fermentation in a 5 L fermenter, which was 4.47-fold that of shake flask fermentation. Overall, the efficient production of cytidine was accomplished through modular metabolic engineering, opening new pathways for the production of cytidine and other nucleosides.

Promoting cytidine biosynthesis by modulating pyrimidine metabolism and carbon metabolic regulatory networks in Bacillus subtilis

BACKGROUND

The modification of single or multiple genes via metabolic engineering can lead to the dysregulation of central metabolism and affect bacterial growth and metabolite accumulation. Meanwhile, transcription factor engineering can trigger metabolic network reprogramming at the global or systemic level, redirecting metabolic flux toward the synthetic pathways of target metabolites. In this study, we modulated pyrimidine and carbon-nitrogen metabolism in Bacillus subtilis through transcription factor engineering to promote the synthesis of cytidine, a drug intermediate.

RESULTS

First, cytidine synthesis was enhanced by knocking out the transcriptional regulator PyrR, which increased the cytidine titer during shake flask fermentation to 0.67 g/L. Second, mutations in the transcriptional regulator catabolite control protein A (CcpA) significantly promoted cytidine synthesis, increasing the shake flask titer to 2.03 g/L. Finally, after culture in a 5 L fermenter, the cytidine titer reached 7.65 g/L, which was 3.77-fold that of shake flask fermentation. Moreover, a cytidine yield and productivity of 0.06 g/g glucose and 0.16 g/L/h, respectively, were achieved. Subsequently, the regulatory mechanisms through which PyrR and CcpA modification affect cytidine biosynthesis were explored through multi-omics analysis. Transcriptome and metabolome analysis revealed that coordinated alterations in carbon, nitrogen, nucleotide, and amino acid metabolism were essential to promote cytidine synthesis. However, the increased cytidine production in recombinant strains was attributed to the enhancement of pyrimidine metabolism, the Phosphotransferase (PTS) system, the tricarboxylic acid (TCA) cycle, the pentose phosphate (PP) pathway, and nitrogen metabolism.

CONCLUSIONS

These results indicate that PyrR knockdown can enhance pyrimidine metabolic pathway and promote cytidine synthesis. CcpA mutation can reprogram the central carbon-nitrogen metabolic network, change the metabolic flow to de novo synthesis pathway of pyrimidine nucleoside, increase the supply of cytidine synthesis precursors and promote the accumulation of cytidine. Overall, regulation of engineered carbon and nitrogen metabolic networks is essential for improving the efficiency of microbial cell factories.

The synergistic effects of citicoline and silymarin on liver injury and thyroid hormone disturbances in γ-irradiated rats

BACKGROUND

Exposure to ionizing radiation is inevitable due to its extensive use in industrial and medical applications. The search for effective and safe natural therapeutic agents as alternatives to chemical drugs is crucial to mitigate their side effects. This study aimed to evaluate the effects of citicoline as a standalone treatment or in combination with the anti-hepatotoxic drug silymarin in protecting against liver injury caused by γ-radiation in rats.

METHODS AND RESULTS

The rats were exposed to γ-radiation (7 Gy) and treated with citicoline (300 mg/kg/day) and/or silymarin (50 mg/kg/day). The results showed that citicoline alleviated liver damage in irradiated rats by reducing hepatic malondialdehyde levels, serum aspartate aminotransferase activity, and inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and nuclear factor-kappa B (NF-κB). It also increased acetylcholine (ACh) levels and the gene expression of the anti-inflammatory protein α7 nicotinic acetylcholine receptor (α7nAChR). Additionally, citicoline improved serum triiodothyronine (T3) levels, thyroid hormone receptor beta (TRβ) gene expression, and iodothyronine deiodinase type 1 activity in hepatic tissues of irradiated rats. Furthermore, citicoline enhanced the effects of silymarin on thyroxine (T4), TRβ, ACh, and α7nAChR when co-administered in irradiated rats. Histopathological analysis confirmed these findings, demonstrating improved liver tissue structure.

CONCLUSIONS

Citicoline mitigates γ-radiation-induced liver damage by reducing oxidative stress, activating the cholinergic anti-inflammatory pathway, and modulating thyroid hormone metabolism. These findings support the use of citicoline as a safe standalone treatment or as an adjuvant with silymarin for managing liver damage and thyroid hormone disturbances caused by γ-irradiation.

Dysregulation of choline metabolism and therapeutic potential of citicoline in Huntington's disease

Huntington's disease (HD) is associated with dysregulated choline metabolism, but the underlying mechanisms remain unclear. This study investigated the expression of key enzymes in this pathway in R6/2 HD mice and human HD postmortem brain tissues. We further explored the therapeutic potential of modulating choline metabolism for HD. Both R6/2 mice and HD patients exhibited reduced expression of glycerophosphocholine phosphodiesterase 1 (GPCPD1), a key enzyme in choline metabolism, in the striatum and cortex. The striatum of R6/2 mice also showed decreased choline and phosphorylcholine, and increased glycerophosphocholine, suggesting disruption in choline metabolism due to GPCPD1 deficiency. Treatment with citicoline significantly improved motor performance, upregulated anti-apoptotic Bcl2 expression, and reduced oxidative stress marker malondialdehyde in both brain regions. Metabolomic analysis revealed partial restoration of disrupted metabolic patterns in the striatum and cortex following citicoline treatment. These findings strongly suggest the role of GPCPD1 deficiency in choline metabolism dysregulation in HD. The therapeutic potential of citicoline in R6/2 mice highlights the choline metabolic pathway as a promising target for future HD therapies.

Real-life management of patients with mild cognitive impairment: an Italian survey

BACKGROUND

Mild cognitive impairment (MCI) is a syndrome with heterogeneous underlying causes and different rates of disease progression, whose clinical heterogeneity leads to a wide variation in diagnostic and therapeutic approaches in clinical practice. The lack of uniform practical recommendations on diagnostic workup and treatment for MCI patients hinders optimal management of these patients, worsening their prognosis. Standardized guidelines for the investigation and follow-up of MCI are therefore urgently required.

AIM

Aim of our study was to assess the diagnostic and therapeutic approach to MCI patients in the setting of Italian Memory Clinics.

METHODS

A survey was delivered to a sample of Italian neurologists through two different phases: a first exploratory phase recording general information about the usual clinical management of patients with MCI, and a subsequent operative phase assessing the practical diagnostic and therapeutic decisions taken in a real life setting to manage subjects with MCI.

RESULTS

A total of 121 neurologists participated to the first phase of the survey and 203 patients were enrolled in the second phase. Information gathered in the first phase of the survey highlighted a non-uniform use of diagnostic criteria and procedures for MCI, as well as a very heterogeneous therapeutic strategy among Italian neurologists. In the second phase, recorded data on diagnostic and therapeutic approach confirmed the large variability observed in the first phase of the survey.

CONCLUSIONS

The results of our study reflect a suboptimal management of MCI patients in Italy and highlight the need of standardized diagnostic and therapeutic approaches for this condition.

Influence of the brain‑gut axis on neuroinflammation in cerebral ischemia‑reperfusion injury (Review)

Stroke, a debilitating cerebrovascular ailment, poses significant threats to human life and health. The intricate interplay between the gut‑brain‑microbiota axis (GBMA) and cerebral ischemia‑reperfusion has increasingly become a focal point of scientific exploration, emerging as a pivotal research avenue in stroke pathophysiology. In the present review, the authors delved into the nexus between the GBMA and neuroinflammation observed post‑stroke. The analysis underscored the pivotal roles of histone deacetylase 3 and neutrophil extracellular traps subsequent to stroke incidents. The influence of gut microbial compositions and their metabolites, notably short‑chain fatty acids and trimethylamine N‑oxide, on neuroinflammatory processes, was further elucidated. The involvement of immune cells, especially regulatory T‑cells, and the intricate signaling cascades including cyclic GMP‑AMP synthase/stimulator of interferon genes/Toll‑like receptor, further emphasized the complex regulatory mechanisms of GBMA in cerebral ischemia/reperfusion injury (CI/RI). Collectively, the present review offered a comprehensive perspective on the metabolic, immune and inflammatory modulations orchestrated by GBMA, augmenting the understanding of its role in neuroinflammation following CI/RI.

Citicoline: A Cholinergic Precursor with a Pivotal Role in Dementia and Alzheimer's Disease

Background

Citicoline is a naturally occurring compound with pleiotropic effects on neuronal function and cognitive processes.

Objective

Based on previous studies, which shed light on the positive effects of citicoline 1 g when combined with acetylcholinesterase inhibitors (AChEIs) and/or memantine, we further investigated the benefits of citicoline in combination therapy in Alzheimer's disease and mixed dementia.

Methods

We integrated the datasets of CITIMEM and CITIDEMAGE, increasing the overall sample size to enhance statistical power. We analyzed data from these two investigator-initiated studies involving 295 patients. The primary outcome was the assessment over time of the effects of combined treatment versus memantine given alone or AChEI plus memantine on cognitive functions assessed by Mini-Mental State Examination (MMSE). The secondary outcomes were the influence of combined treatment on daily life functions, mood, and behavioral symptoms assessed by activities of daily life (ADL) and instrumental ADL, Geriatric Depression Scale, and Neuropsychiatric Inventory Scale. One-hundred-forty-three patients were treated with memantine and/or AChEI (control group), and 152 patients were treated with memantine and/or AChEI plus citicoline 1 g/day orally (Citicoline group).

Results

A significant difference in MMSE score was found in the average between the two groups of treatment at 6 and 12 months.

Conclusions

This study confirmed the effectiveness of combined citicoline treatment in patients with mixed dementia and Alzheimer's disease, with a significant effect on the increase of MMSE score over time. The treated group also showed a significant reduction in the Geriatric Depression Scale and a significant increase in the instrumental ADL scale.

CDP-choline to promote remyelination in multiple sclerosis: the need for a clinical trial

Multiple sclerosis is a multifactorial chronic inflammatory disease of the central nervous system that leads to demyelination and neuronal cell death, resulting in functional disability. Remyelination is the natural repair process of demyelination, but it is often incomplete or fails in multiple sclerosis. Available therapies reduce the inflammatory state and prevent clinical relapses. However, therapeutic approaches to increase myelin repair in humans are not yet available. The substance cytidine-5'-diphosphocholine, CDP-choline, is ubiquitously present in eukaryotic cells and plays a crucial role in the synthesis of cellular phospholipids. Regenerative properties have been shown in various animal models of diseases of the central nervous system. We have already shown that the compound CDP-choline improves myelin regeneration in two animal models of multiple sclerosis. However, the results from the animal models have not yet been studied in patients with multiple sclerosis. In this review, we summarise the beneficial effects of CDP-choline on biolipid metabolism and turnover with regard to inflammatory and regenerative processes. We also explain changes in phospholipid and sphingolipid homeostasis in multiple sclerosis and suggest a possible therapeutic link to CDP-choline.

CDP-choline modulates cholinergic signaling and gut microbiota to alleviate DSS-induced inflammatory bowel disease

Inflammatory bowel diseases (IBD) represent chronic gastrointestinal inflammatory disorders characterized by a complex and underexplored pathogenic mechanism. Previous research has revealed that IBD patients often have a deficiency of choline and its metabolites, including acetylcholine (ACh) and phosphatidylcholine (PC), within the colon. However, a comprehensive study linking these three substances and their mechanistic implications in IBD remains lacking. This study aimed to investigate the efficacy and underlying mechanism of cytidine diphosphate (CDP)-choline (citicoline), an intermediate product of choline metabolism, in a mouse model of IBD induced by dextran sulfate sodium salt (DSS). The results demonstrated that CDP-choline effectively alleviated colonic inflammation and deficiencies in choline, ACh, and PC by increasing the raw material. Further detection showed that CDP-choline also increased the ACh content by altering the expression of high-affinity choline transporter (ChT1) and acetylcholinesterase (AChE) in DSS-induced mice colon. Moreover, CDP-choline increased the expression of alpha7 nicotinic acetylcholine receptor (α7 nAChR) and activated the cholinergic anti-inflammatory pathway (CAP), leading to reduced colon macrophage activation and proinflammatory M1 polarization in IBD mice, thus reducing the levels of TNF-α and IL-6. In addition, CDP-choline reduced intestinal ecological imbalance and increased the content of hexanoic acid in short-chain fatty acids (SCFAs) in mice. In conclusion, this study elucidates the ability of CDP-choline to mitigate DSS-induced colon inflammation by addressing choline and its metabolites deficiencies, activating the CAP, and regulating the composition of the intestinal microbiome and SCFAs content, providing a potential prophylactic and therapeutic approach for IBD.

Analysis of Fecal Microbiota in Patients with Hypertension Complicated with Ischemic Stroke

Ischemic stroke is a disease with a very high incidence in the clinic, and hypertension is the most important variable risk factor of ischemic stroke. Studies have shown that intestinal microbes are involved in the occurrence and development of various diseases. This study aims to explore whether intestinal microbes play an important role in the pathogenesis of ischemic stroke in a hypertensive population. In this study, the inpatients in the Department of Neurology and Cardiology of the Second Affiliated Hospital of Shandong First Medical University in April 2021 were selected, including seven patients with hypertension complicated with ischemic stroke and only seven patients with hypertension. After collecting the stool samples of patients, the gene sequence of the samples was detected by 16S rRNA sequencing technology, and the double-ended 2 × 150 bp sequencing was carried out. After sequencing, the results were analyzed by diversity analysis, species difference analysis, species function difference analysis, and other bioinformatics tests. According to the test results, serum proteomics and biochemical blood tests were carried out to verify. There was no significant difference in α diversity and β diversity between hypertension complicated with the cerebral infarction and hypertension groups. LEfSe analysis showed that at the genus level, compared with the hypertension group, Bacteroides, UCG_009, and Eisenbergiella had significantly increased relative abundance. The genera with relatively significantly reduced abundance are Ruminococcus_gnavus_group, Sutterellaceae, Burkholderia, and Prevotella and the LDA score of Prevotella is <  - 4, which indicates that there are significant differences. Compared with the blood biochemical indexes, the results showed that the level of APOA1 in hypertensive patients with ischemic stroke was significantly higher than that in hypertensive patients (p < 0.05), but there was no significant difference in total cholesterol (CHOL), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoprotein B (APOB), and free fatty acid (NEFA). Proteomic analysis showed that there were 89 up-regulated genes and 51 down-regulated genes in the serum of the two groups, and the expression of APOC2 and APOC3 in the cerebral infarction group with hypertension was significantly higher than that in the hypertension group (p < 0.05). The intestinal diversity of patients with hypertension complicated with stroke is similar to that of patients with hypertension, but there are differences in microbiota, among which Prevotella is the most significant. Prevotella could affect lipid metabolism so that APOC2 and APOC3 in the blood are significantly increased, leading to cerebral artery atherosclerosis and, finally, ischemic stroke. This provides a new idea for preventing and treating ischemic stroke in patients with hypertension, but the mechanism of Prevotella acting on apolipoprotein needs further verification by basic medical research.

Restored retinal physiology after administration of niacin with citicoline in a mouse model of hypertensive glaucoma

Introduction

Much interest has been addressed to antioxidant dietary supplements that are known to lower the risk of developing glaucoma or delay its progression. Among them, niacin and citicoline protect retinal ganglion cells (RGCs) from degeneration by targeting mitochondria, though at different levels. A well-established mouse model of RGC degeneration induced by experimental intraocular pressure (IOP) elevation was used to investigate whether a novel combination of niacin/citicoline has better efficacy over each single component in preserving RGC health in response to IOP increase.

Methods

Ocular hypertension was induced by an intracameral injection of methylcellulose that clogs the trabecular meshwork. Electroretinography and immunohistochemistry were used to evaluate RGC function and density. Oxidative, inflammatory and apoptotic markers were evaluated by Western blot analysis.

Results

The present results support an optimal efficacy of niacin with citicoline at their best dosage in preventing RGC loss. In fact, about 50% of RGCs were spared from death leading to improved electroretinographic responses to flash and pattern stimulation. Upregulated levels of oxidative stress and inflammatory markers were also consistently reduced by almost 50% after niacin with citicoline thus providing a significant strength to the validity of their combination.

Conclusion

Niacin combined with citicoline is highly effective in restoring RGC physiology but its therapeutic potential needs to be further explored. In fact, the translation of the present compound to humans is limited by several factors including the mouse modeling, the higher doses of the supplements that are necessary to demonstrate their efficacy over a short follow up period and the scarce knowledge of their transport to the bloodstream and to the eventual target tissues in the eye.

Citicoline on the Barthel Index: Severe and moderate brain injury

INTRODUCTION

Traumatic brain injury (TBI) is a paramount factor in mortality and morbidity. The clinical trials conducted to investigate the efficacy of neuroprotective agents, such as citicoline, as a therapeutic alternative for TBI have presented divergent findings. Therefore, this study aimed to evaluate and compare citicoline's effect on the Barthel Index in patients with severe and moderate brain injury.

MATERIALS AND METHODS

The study is a randomized clinical trial. Patients in the case group (35 patients) were treated with citicoline and the control group (34 patients) received a placebo. Data were analyzed using SPSS 16 software.

RESULTS

The results showed that changes in the Glasgow Coma Scale, changes in quadriceps muscle force score, Barthel Index score changes, achieving the status without intubation, and spontaneous breathing in patients treated with citicoline were not a statistically significant difference in the two groups (P > 0.05).

CONCLUSION

Findings revealed that citicoline did not impact the recovery process of severe and moderate TBI patients.

Valuable effects of lactobacillus and citicoline on steatohepatitis: role of Nrf2/HO-1 and gut microbiota

Non-alcoholic steatohepatitis (NASH) is a more dangerous form of chronic non-alcoholic fatty liver disease (NAFLD). In the current investigation, the influence of citicoline on high-fat diet (HFD)-induced NASH was examined, both alone and in combination with Lactobacillus (probiotic). NASH was induced by feeding HFD (10% sugar, 10% lard stearin, 2% cholesterol, and 0.5% cholic acid) to rats for 13 weeks and received single i.p. injection of streptozotocin (STZ, 30 mg/kg) after 4 weeks. Citicoline was given at two dose levels (250 mg and 500 mg, i.p.) at the beginning of the sixth week, and in combination with an oral suspension of Lactobacillus every day for eight weeks until the study's conclusion. HFD/STZ induced steatohepatitis as shown by histopathological changes, elevated serum liver enzymes, serum hyperlipidemia and hepatic fat accumulation. Moreover, HFD convinced oxidative stress by increased lipid peroxidation marker (MDA) and decreased antioxidant enzymes (GSH and TAC). Upregulation of TLR4/NF-kB and the downstream inflammatory cascade (TNF-α, and IL-6) as well as Pentaraxin, fetuin-B and apoptotic markers (caspase-3 and Bax) were observed. NASH rats also had massive increase in Bacteroides spp., Fusobacterium spp., E. coli, Clostridium spp., Providencia spp., Prevotella interrmedia, and P. gingivalis while remarkable drop in Bifidobacteria spp. and Lactobacillus spp. Co-treatment with citicoline alone and with Lactobacillus improve histopathological NASH outcomes and reversed all of these molecular pathological alterations linked to NASH via upregulating the expression of Nrf2/HO-1 and downregulating TLR4/NF-kB signaling pathways. These results suggest that citicoline and lactobacillus may represent new hepatoprotective strategies against NASH progression.

Valuable effects of lactobacillus and citicoline on steatohepatitis: role of Nrf2/HO-1 and gut microbiota

Non-alcoholic steatohepatitis (NASH) is a more dangerous form of chronic non-alcoholic fatty liver disease (NAFLD). In the current investigation, the influence of citicoline on high-fat diet (HFD)-induced NASH was examined, both alone and in combination with Lactobacillus (probiotic). NASH was induced by feeding HFD (10% sugar, 10% lard stearin, 2% cholesterol, and 0.5% cholic acid) to rats for 13 weeks and received single i.p. injection of streptozotocin (STZ, 30 mg/kg) after 4 weeks. Citicoline was given at two dose levels (250 mg and 500 mg, i.p.) at the beginning of the sixth week, and in combination with an oral suspension of Lactobacillus every day for eight weeks until the study’s conclusion. HFD/STZ induced steatohepatitis as shown by histopathological changes, elevated serum liver enzymes, serum hyperlipidemia and hepatic fat accumulation. Moreover, HFD convinced oxidative stress by increased lipid peroxidation marker (MDA) and decreased antioxidant enzymes (GSH and TAC). Upregulation of TLR4/NF-kB and the downstream inflammatory cascade (TNF-α, and IL-6) as well as Pentaraxin, fetuin-B and apoptotic markers (caspase-3 and Bax) were observed. NASH rats also had massive increase in Bacteroides spp., Fusobacterium spp., E. coli, Clostridium spp., Providencia spp., Prevotella interrmedia, and P. gingivalis while remarkable drop in Bifidobacteria spp. and Lactobacillus spp. Co-treatment with citicoline alone and with Lactobacillus improve histopathological NASH outcomes and reversed all of these molecular pathological alterations linked to NASH via upregulating the expression of Nrf2/HO-1 and downregulating TLR4/NF-kB signaling pathways. These results suggest that citicoline and lactobacillus may represent new hepatoprotective strategies against NASH progression.

Is Citicoline Effective in Preventing and Slowing Down Dementia?-A Systematic Review and a Meta-Analysis

BACKGROUND

Cognitive impairment is a staggering personal and societal burden; accordingly, there is a strong interest in potential strategies for its prevention and treatment. Nutritional supplements have been extensively investigated, and citicoline seems to be a promising agent; its role in clinical practice, however, has not been established. We systematically reviewed studies on the effect of citicoline on cognitive performance.

METHODS

We searched the PubMed and Cochrane Library databases for articles published between 2010 and 2022. Relevant information was extracted and presented following the PRISMA recommendations. Data were pooled using the inverse-variance method with random effects models.

RESULTS

We selected seven studies including patients with mild cognitive impairment, Alzheimer's disease or post-stroke dementia. All the studies showed a positive effect of citicoline on cognitive functions. Six studies could be included in the meta-analysis. Overall, citicoline improved cognitive status, with pooled standardized mean differences ranging from 0.56 (95% CI: 0.37-0.75) to 1.57 (95% CI: 0.77-2.37) in different sensitivity analyses. The overall quality of the studies was poor.

DISCUSSION

Available data indicate that citicoline has positive effects on cognitive function. The general quality of the studies, however, is poor with significant risk of bias in favor of the intervention. Other: PubMed and the Cochrane Library.

Choline supplements: An update

In this comprehensive review, we examine the main preclinical and clinical investigations assessing the effects of different forms of choline supplementation currently available, including choline alfoscerate (C₈H₂₀NO₆P), also known as alpha-glycerophosphocholine (α-GPC, or GPC), choline bitartrate, lecithin, and citicoline, which are cholinergic compounds and precursors of acetylcholine. Extensively used as food supplements, they have been shown to represent an effective strategy for boosting memory and enhancing cognitive function.

Citicoline: pharmacological and clinical review, 2022 update

This review is based on the previous one published in 2016 (Secades JJ. Citicoline: pharmacological and clinical review, 2016 update. Rev Neurol 2016; 63 (Supl 3): S1-S73), incorporating 176 new references, having all the information available in the same document to facilitate the access to the information in one document. This review is focused on the main indications of the drug, as acute stroke and its sequelae, including the cognitive impairment, and traumatic brain injury and its sequelae. There are retrieved the most important experimental and clinical data in both indications.

Adverse effects associated with use of specific dietary supplements: The US Military Dietary Supplement Use Study

Dietary supplements (DSs) are used by 50% of Americans and 70% of United States military service members (SMs); some have adverse effects (AEs). This cross-sectional investigation examined AEs associated with specific DSs. A stratified random sample of SMs from the Air Force, Army, Marine Corps, and Navy was obtained. Volunteers completed a questionnaire reporting AEs for 96 generic and 62 specific DSs. The highest prevalence (≥1 AE) in specific DS categories was 35% prohormones, 33% weight loss supplements, 26% pre/post workout supplements, 14% herbal products, 12% multivitamin/multiminerals, 11% protein/amino acids, 9% muscle building supplements, 7% other DSs, 6% joint health products, and 5% individual vitamins/minerals. Specific DSs of concern (with proportion reporting AEs) included: Libido Max® (35%), Hydroxycut Hardcore® (33%), OxyElite® (33%), Roxylean® (31%), Growth Factor 9® (30%), Super HD® (29%), Hydroxycut Advanced® (29%), Lipo 6® (28%), The Ripper® (27%), Test Booster® (27%), Xenadrine Xtreme Thermogenic® (27%), C4 Extreme® (26%), and C4 Origional® (25%). Products marketed for weight loss, use before/after workout, and prohormones had the highest AE prevalence. DSs can contain substances with independent/additive AEs and/or interact with other ingredients or prescribed medications. Methods described here could provide a continuous surveillance system detecting dangerous DSs entering the market.

Citicoline for Supporting Memory in Aging Humans

Citicoline is the generic name of CDP-choline, a natural metabolite present in all living cells. Used in medicine as a drug since the 1980-s, citicoline was recently pronounced a food ingredient. When ingested, citicoline breaks down to cytidine and choline, which become incorporated into their respective normal metabolic pathways. Choline is a precursor of acetylcholine and phospholipids; these is a neurotransmitter pivotal for learning and memory and important constituents of neuronal membranes and myelin sheaths, respectively. Cytidine in humans is readily converted to uridine, which exerts a positive effect on synaptic function and supports the formation of synaptic membranes. Choline deficiency has been found to be correlated with memory dysfunction. Magnetic resonance spectroscopy studies showed that citicoline intake improves brain uptake of choline in older persons, suggestive of that it shall help in reversing early age-related cognitive changes. In randomized, placebo-controlled trials of cognitively normal middle-aged and elderly persons, positive effects of citicoline on memory efficacy were found. Similar effects of citicoline on memory indices were also found in patients suffering from mild cognitive impairment and some other neurological diseases. Altogether, the aforementioned data provide complex and unambiguous evidence supporting the claim that oral citicoline intake positively influences memory function in humans who encounter age-related memory impairment also in the absence of any detectable neurological or psychiatric disease.

An Overview of Combination Treatment with Citicoline in Dementia

INTRODUCTION

The present article reports an overview of the studies about combination treatment with citicoline of Alzheimer's (AD) and mixed dementia (MD).

METHODS

A Medline search was carried out by using the keywords Alzheimer's dementia, mixed dementia, older people, treatment with citicoline, memantine, and acetylcholinesterase inhibitors (AchEIs).

RESULTS

Six studies were found to match the combination treatment of citicoline with AcheIs and/or memantine. The CITIRIVAD and CITICHOLINAGE studies were the first to report the potential benefits of adding citicoline to acetylcholinesterase inhibitors (AchEIs). Then, we added citicoline to memantine in the CITIMEM study, and finally, we demonstrated benefits in terms of delay in cognitive worsening with the triple therapy (citicoline + AchEIs + memantine). Other authors also reinforced our hypothesis through two further studies.

CONCLUSIONS

Open, prospective studies are advised to confirm the utility of combination therapy with citicoline for the treatment of AD and MD.

Regenerative Effects of CDP-Choline: A Dose-Dependent Study in the Toxic Cuprizone Model of De- and Remyelination

Inflammatory attacks and demyelination in the central nervous system (CNS) are the key factors responsible for the damage of neurons in multiple sclerosis (MS). Remyelination is the natural regenerating process after demyelination that also provides neuroprotection but is often incomplete or fails in MS. Currently available therapeutics are affecting the immune system, but there is no substance that might enhance remyelination. Cytidine-S-diphosphate choline (CDP-choline), a precursor of the biomembrane component phospholipid phosphatidylcholine was shown to improve remyelination in two animal models of demyelination. However, the doses used in previous animal studies were high (500 mg/kg), and it is not clear if lower doses, which could be applied in human trials, might exert the same beneficial effect on remyelination. The aim of this study was to confirm previous results and to determine the potential regenerative effects of lower doses of CDP-choline (100 and 50 mg/kg). The effects of CDP-choline were investigated in the toxic cuprizone-induced mouse model of de- and remyelination. We found that even low doses of CDP-choline effectively enhanced early remyelination. The beneficial effects on myelin regeneration were accompanied by higher numbers of oligodendrocytes. In conclusion, CDP-choline could become a promising regenerative substance for patients with multiple sclerosis and should be tested in a clinical trial.

Understanding Choline Bioavailability and Utilization: First Step Toward Personalizing Choline Nutrition

Choline is an essential macronutrient involved in neurotransmitter synthesis, cell-membrane signaling, lipid transport, and methyl-group metabolism. Nevertheless, the vast majority are not meeting the recommended intake requirement. Choline deficiency is linked to nonalcoholic fatty liver disease, skeletal muscle atrophy, and neurodegenerative diseases. The conversion of dietary choline to trimethylamine by gut microbiota is known for its association with atherosclerosis and may contribute to choline deficiency. Choline-utilizing bacteria constitutes less than 1% of the gut community and is modulated by lifestyle interventions such as dietary patterns, antibiotics, and probiotics. In addition, choline utilization is also affected by genetic factors, further complicating the impact of choline on health. This review overviews the complex interplay between dietary intakes of choline, gut microbiota and genetic factors, and the subsequent impact on health. Understanding of gut microbiota metabolism of choline substrates and interindividual variability is warranted in the development of personalized choline nutrition.

A Retrospective Study on the Benefits of Combined Citicoline, Memantine, and Acetylcholinesterase Inhibitor Treatments in Older Patients Affected with Alzheimer's Disease

BACKGROUND

Background: Citicoline has been proven to have beneficial effects in patients with cognitive impairment. In previous studies, combined treatment with memantine and acetylcholinesterase inhibitors (AChEIs) maintained cognitive function in patients with Alzheimer's disease (AD) better than memantine or AChEIs alone.

OBJECTIVE

To evaluate the effectiveness and safety of a combination therapy of oral citicoline, memantine, and an AChEI in AD when compared with memantine and an AChEI without citicoline.

METHODS

This was a retrospective multi-centric case-control study, conducted in Italian Centers for Cognitive Impairment and Dementia. Overall, 170 patients were recruited (34.11%of men, mean age 76,81±4.93 years): 48.8%treated with memantine and donepezil; 48.2%with memantine and rivastigmine; 2.9%with memantine and galantamine. 89 patients (control-group) were treated with memantine and an AChEI, whereas 81 patients (case-group) were treated with oral citicoline 1000 mg/day added to memantine and an AChEI given orally. Cognitive functions, activities of daily living, instrumental activities of daily living, comorbidities, mood and behavioral disturbances were assessed at baseline, month 6, and month 12.

RESULTS

In the case group, MMSE score had a statistically significant increasing trend between T0 and T2 (14.88±2.95 versus 15.09±3.00; p = 0.040), whereas in the control group, MMSE score showed a statistically significant decrease trend (14.37±2.63 versus 14.03±2.92 p = 0.024).

CONCLUSION

In older patients with AD, a triple therapy with citicoline, memantine, and AChEI was more effective than memantine and AChEI without citicoline in maintaining the MMSE total score after 12 months.

The effects of twenty-one nutrients and phytonutrients on cognitive function: A narrative review

BACKGROUND AND AIM

Brain health is becoming more important to the average person as the number of people with cognitive impairments, such as Alzheimer's disease (AD), is rising significantly. The current Food and Drug Administration-approved pharmacotherapeutics for dementia neither cure nor halt cognitive decline; they just delay the worsening cognitive impairment. This narrative review summarizes the effects of nutrients and phytonutrients on cognitive function.

METHODS

A comprehensive literature search of PubMed was performed to find clinical trials in humans that assessed the effects of nutrients and phytonutrients on cognitive function published in English between 2000 and 2021. Six independent reviewers evaluated the articles for inclusion in this review.

RESULTS

Ninety-six articles were summarized in this narrative review. In total 21 categories of nutrients and phytonutrients were included, i.e., α-lipoic acid, Bacopa monnieri, B vitamins, cholinergic precursors, vitamin D, vitamin E, Ginkgo biloba, ginseng, lion's mane mushroom, N-acetyl cysteine, omega-3 fatty acids, aloe polysaccharides, Rhodiola rosea, rosemary, saffron, tart cherries, turmeric, wild yam, Withania somnifera, xanthines, and zinc. Particular noteworthy effects on cognition included memory, recollection, attention, intelligence, vocabulary, recognition, response inhibition, arousal, performance enhancement, planning, creative thinking, reaction time, vigilance, task switching, orientation to time, place, and person, reading, writing, comprehension, accuracy, learning, information processing speed, executive function, mental flexibility, daily functioning, decrease in mental fatigue, and freedom from distractibility. Some nutrients and phytonutrients also improved mood and contentedness and reduced anxiety and the need for caregiving. These effects are not completely consistent or ubiquitous across all patient populations or health statuses. Adverse effects were minimal or nonexistent.

CONCLUSION

Due to the growing population of people with cognitive impairment and the lack of effective pharmacotherapeutics, it is prudent for those afflicted or their caregivers to find alternative treatments. Our narrative review shows that many of these nutrients and phytonutrients may be promising for treating some aspects of cognitive impairment, especially for people afflicted with AD.

RELEVANCE FOR PATIENTS

As demonstrated in a number of clinical trials, healthy adults and patients with various health challenges (e.g., AD, mild cognitive impairment, multiple sclerosis, and Parkinson's disease) exhibiting a wide range of severity in cognitive defects would be best served to consider multiple nutrients and phytonutrients to improve aspects of their cognitive function.

Citicoline: A Candidate for Adjunct Treatment of Multiple Sclerosis

In remitting–relapsing multiple sclerosis (RR-MS), relapses are driven by autoreactive immune cells that enter the brain and spinal cord and damage myelin sheaths of axons in white and grey matter, whereas during remissions myelin is repaired by activated oligodendroglial cells. Disease-modifying therapies (DMTs) may either retard/attenuate myelin damage or promote/enhance/speed up myelin repair. Almost all currently approved DMTs inhibit myelin damage and are considerably toxic. Enhancement of myelin repair is considered an unmet medical need of MS patients. Citicoline, known for many years as a nootropic and neuroprotective drug and recently pronounced food supplement, has been found to be significantly efficacious in two complementary rodent models of MS, experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced myelin toxicity. Moreover, citicoline treatment improves visual evoked potentials (VEPs) in glaucoma patients, which is relevant because VEP monitoring is frequently used as an indicator of remyelination in MS. Although over-the-counter availability of citicoline may impede its formal translation to the clinic of MS, evaluation of its efficacy for supporting remyelination in this disease is strongly indicated.

Application of Citicoline in Neurological Disorders: A Systematic Review

Citicoline is a chemical compound involved in the synthesis of cell membranes. It also has other, not yet explained functions. Research on the use of citicoline is conducted in neurology, ophthalmology, and psychiatry. Citicoline is widely available as a dietary supplement. It is often used to enhance cognitive functions. In our article, accessible databases were searched for articles regarding citicoline use in neurological diseases. This article has a systemic review form. After rejecting non-eligible reports, 47 remaining articles were reviewed. The review found that citicoline has been proven to be a useful compound in preventing dementia progression. It also enhances cognitive functions among healthy individuals and improves prognosis after stroke. In an animal model of nerve damage and neuropathy, citicoline stimulated regeneration and lessened pain. Among patients who underwent brain trauma, citicoline has an unclear clinical effect. Citicoline has a wide range of effects and could be an essential substance in the treatment of many neurological diseases. Its positive impact on learning and cognitive functions among the healthy population is also worth noting.

Spatial Metabolomics of the Human Kidney using MALDI Trapped Ion Mobility Imaging Mass Spectrometry

Low molecular weight metabolites are essential for defining the molecular phenotypes of cells. However, spatial metabolomics tools often lack the sensitivity, specify, and spatial resolution to provide comprehensive descriptions of these species in tissue. MALDI imaging mass spectrometry (IMS) of low molecular weight ions is particularly challenging as MALDI matrix clusters are often nominally isobaric with multiple metabolite ions, requiring high resolving power instrumentation or derivatization to circumvent this issue. An alternative to this is to perform ion mobility separation before ion detection, enabling the visualization of metabolites without the interference of matrix ions. Additional difficulties surrounding low weight metabolite visualization include high resolution imaging, while maintaining sufficient ion numbers for broad and representative analysis of the tissue chemical complement. Here, we use MALDI timsTOF IMS to image low molecular weight metabolites at higher spatial resolution than most metabolite MALDI IMS experiments (20 μm) while maintaining broad coverage within the human kidney. We demonstrate that trapped ion mobility spectrometry (TIMS) can resolve matrix peaks from metabolite signal and separate both isobaric and isomeric metabolites with different distributions within the kidney. The added ion mobility data dimension dramatically increased the peak capacity for spatial metabolomics experiments. Through this improved sensitivity, we have found >40 low molecular weight metabolites in human kidney tissue, such as argininic acid, acetylcarnitine, and choline that localize to the cortex, medulla, and renal pelvis, respectively. Future work will involve further exploring metabolomic profiles of human kidneys as a function of age, sex, and race.

Cytidine 5'-Diphosphocholine (Citicoline): Evidence for a Neuroprotective Role in Glaucoma

Glaucoma, a heterogeneous set of progressively degenerative optic neuropathies characterized by a loss of retinal ganglion cells (RGCs) and typical visual field deficits that can progress to blindness, is a neurodegenerative disease involving both ocular and visual brain structures. Although elevated intraocular pressure (IOP) remains the most important modifiable risk factor of primary open-angle glaucoma (POAG) and is the main therapeutic target in treating glaucoma, other factors that influence the disease course are involved and reaching the optimal IOP target does not stop the progression of glaucoma, as the visual field continues to narrow. In addition to a managed IOP, neuroprotection may be beneficial by slowing the progression of glaucoma and improving the visual defects. Citicoline (cytidine 5'-diphosphocholine) is a naturally occurring endogenous compound that has been investigated as a novel therapeutic agent for the management of glaucoma. Citicoline has demonstrated activity in a range of central neurodegenerative diseases, and experimental evidence suggests a it performs a neuromodulator and neuroprotective role on neuronal cells, including RGCs, associated with improvement in visual function, extension of the visual field and central benefits for the patient. This review aims to critically summarize the current evidence for the neuroprotective properties of citicoline in glaucoma.

Maternal Citicoline-Supplemented Diet Improves the Response of the Immature Hippocampus to Perinatal Asphyxia in Rats

BACKGROUND

Citicoline represents a dietary source of choline, an essential nutrient, and precursor of cell membrane components, highly required during development and post-injury recovery.

OBJECTIVES

We previously showed that perinatal asphyxia (PA) induces hippocampal neuroinflammation and injury that are subject to epigenetic change by maternal diet. The present study investigates maternal citicoline-supplemented diet (CSD) impact on offspring hippocampal response to PA.

METHODS

Six-day-old Wistar rats from mothers with standard-diet or CSD were exposed to PA. The hippocampal inflammation and injury were assessed by interleukin-1 beta (IL-1b), tumor necrosis factor-alpha (TNFα), and S-100B protein (S-100B), 24-48 h post-asphyxia. The microRNAs species miR124, miR132, miR134, miR146, and miR15a were measured from the hippocampus 24 h post-asphyxia, to investigate its epigenetic response to PA and maternal diet. At maturity, the offspring's behavior was analyzed using open field (OFT), T-maze (TMT), and forced swimming (FST) tests.

RESULTS

Our data show that the maternal CSD decreased IL-1b (p = 0.02), TNFα (p = 0.007), and S100B (p = 0.01) at 24 h postexposure, upregulated miR124 (p = 0.03), downregulated miR132 (p = 0.002) and miR134 (p = 0.001), shortened the immobility period in FST (p = 0.01), and increased the percentage of passed trials in TMT (p = 0.01) compared to standard-diet.

CONCLUSIONS

Maternal CSD reduces hippocampal inflammation and S100B level, triggers epigenetic changes related to homeostatic synaptic plasticity, memory formation, and neuronal tolerance to asphyxia, decreases the depressive-like behavior, and improves the lucrative memory in offspring subjected to PA. Thus, citicoline could be valuable as a maternal dietary strategy in improving the brain response to PA.