citicoline (CDP-choline) in hospitalized SARS CoV-2-infected patients with hypoxemic acute respiratory failure

BACKGROUND

The SARS CoV-2 pandemic has resulted in more than 1.1 million deaths in the USA alone. Therapeutic options for critically ill patients with COVID-19 are limited. Prior studies showed that post-infection treatment of influenza A virus-infected mice with the liponucleotide CDP-choline, which is an essential precursor for de novo phosphatidylcholine synthesis, improved gas exchange and reduced pulmonary inflammation without altering viral replication. In unpublished studies, we found that treatment of SARS CoV-2-infected K18-hACE2-transgenic mice with CDP-choline prevented development of hypoxemia. We hypothesize that administration of citicoline (the pharmaceutical form of CDP-choline) will be safe in hospitalized SARS CoV-2-infected patients with hypoxemic acute respiratory failure (HARF) and that we will obtain preliminary evidence of clinical benefit to support a larger Phase 3 trial using one or more citicoline doses.

METHODS

We will conduct a single-site, double-blinded, placebo-controlled, and randomized Phase 1/2 dose-ranging and safety study of Somazina® citicoline solution for injection in consented adults of any sex, gender, age, or ethnicity hospitalized for SARS CoV-2-associated HARF. The trial is named "SCARLET" (Supplemental Citicoline Administration to Reduce Lung injury Efficacy Trial). We hypothesize that SCARLET will show that i.v. citicoline is safe at one or more of three doses (0.5, 2.5, or 5 mg/kg, every 12 h for 5 days) in hospitalized SARS CoV-2-infected patients with HARF (20 per dose) and provide preliminary evidence that i.v. citicoline improves pulmonary outcomes in this population. The primary efficacy outcome will be the SpO2:FiO2 ratio on study day 3. Exploratory outcomes include Sequential Organ Failure Assessment (SOFA) scores, dead space ventilation index, and lung compliance. Citicoline effects on a panel of COVID-relevant lung and blood biomarkers will also be determined.

DISCUSSION

Citicoline has many characteristics that would be advantageous to any candidate COVID-19 therapeutic, including safety, low-cost, favorable chemical characteristics, and potentially pathogen-agnostic efficacy. Successful demonstration that citicoline is beneficial in severely ill patients with SARS CoV-2-induced HARF could transform management of severely ill COVID patients.

TRIAL REGISTRATION

The trial was registered at www.

CLINICALTRIALS

gov on 5/31/2023 (NCT05881135).

TRIAL STATUS

Currently enrolling.

The effects of CDP-choline treatment in Amanita phalloides mushroom toxicosis

Amanita phalloides poisoning is known to be the most fatal case among mushroom poisoning cases. Its main mechanism of toxicity is that it leads to cell death by the irreversible binding of its toxins to the DNA-dependent RNA polymerase II enzyme. This study was planned to analyze the effects of the CDP-choline molecule on Amanita phalloides mushroom poisoning cases. The extract of the Amanita phalloides mushroom was taken and intraperitoneally administered to male Wistar Albino rats at a dose of 0.3 g/kg. In the experiment phase, the rats were divided into three groups of CDP-choline treatment according to the doses of 100 mg/kg, 250 mg/kg, and 500 mg/kg, and one control group was administered a 1 ml/kg dose of 0.9% isotonic NaCl solution. The treatments were then administered intraperitoneally at the 2nd hour, and at the 6th hour, the rats were sacrificed. The degree of damage in the liver and kidney tissues of the rats was evaluated histopathologically. It was concluded that CDP-choline reduced or prevented the damage that occurred in the liver significantly and dose-dependently in the toxicosis picture caused by Amanita phalloides, and it showed a tendency to lower or prevent the damage in the kidney, albeit not significantly.

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.

Choline-Containing Phospholipids in Stroke Treatment: A Systematic Review and Meta-Analysis

BACKGROUND

Globally, stroke is the second leading cause of death and disability. In different studies conducted previously, the choline-containing phospholipids citicoline and choline alphoscerate have been proposed as adjuvants in the treatment of acute strokes. A systematic review was conducted to provide updated information on the effects of citicoline and choline alphoscerate in patients with acute and hemorrhagic strokes.

METHODS

PubMed/Medline, Scopus, and Web of Science were searched to identify relevant materials. Data were pooled, and odds ratios (OR) were reported for binary outcomes. Using mean differences (MD), we evaluated continuous outcomes.

RESULTS

A total of 1460 studies were reviewed; 15 studies with 8357 subjects met the eligibility criteria and were included in the analysis. In our study, citicoline treatment did not result in improved neurological function (NIHSS < 1, OR = 1.05; 95% confidence interval (CI): 0.87-1.27) or functional recovery (mRS < 1, OR = 1.36; 95% CI: 0.99-1.87) in patients with acute stroke. Choline alphoscerate improved neurological function and functional recovery in stroke patients based on the Mathew's scale and the Mini-Mental State Examination (MMSE).

CONCLUSION

Citicoline did not improve the neurological or functional outcomes in acute stroke patients. In contrast, choline alphoscerate improved neurological function and functional recovery and reduced dependency in stroke patients.

An α7 nAChR approach for the baseline-dependent modulation of deviance detection in schizophrenia: A pilot study assessing the combined effect of CDP-choline and galantamine

BACKGROUND

Cognitive operations including pre-attentive sensory processing are markedly impaired in patients with schizophrenia (SCZ) but evidence significant interindividual heterogeneity, which moderates treatment response with nicotinic acetylcholine receptor (nAChR) agonists. Previous studies in healthy volunteers have shown baseline-dependency effects of the α7 nAChR agonist cytidine 5'-diphosphocholine (CDP-choline) administered alone and in combination with a nicotinic allosteric modulator (galantamine) on auditory deviance detection measured with the mismatch negativity (MMN) event-related potential (ERP).

AIM

The objective of this pilot study was to assess the acute effect of this combined α7 nAChR-targeted treatment (CDP-choline/galantamine) on speech MMN in patients with SCZ (N = 24) stratified by baseline MMN responses into low, medium, and high baseline auditory deviance detection subgroups.

METHODS

Patients with a stable diagnosis of SCZ attended two randomized, double-blind, placebo-controlled and counter-balanced testing sessions where they received a placebo or a CDP-choline (500 mg) and galantamine (16 mg) treatment. MMN ERPs were recorded during the presentation of a fast multi-feature speech MMN paradigm including five speech deviants. Clinical measures were acquired before and after treatment administration.

RESULTS

While no main treatment effect was observed, CDP-choline/galantamine significantly increased MMN amplitudes to frequency, duration, and vowel speech deviants in low group individuals. Individuals with higher positive and negative symptom scale negative, general, and total scores expressed the greatest MMN amplitude improvement following CDP-choline/galantamine.

CONCLUSIONS

These baseline-dependent nicotinic effects on early auditory information processing warrant different dosage and repeated administration assessments in patients with low baseline deviance detection levels.

Citicoline for the Management of Patients with Traumatic Brain Injury in the Acute Phase: A Systematic Review and Meta-Analysis

BACKGROUND

Citicoline or CDP-choline is a neuroprotective/neurorestorative drug used in several countries for the treatment of traumatic brain injury (TBI). Since the publication of the controversial COBRIT, the use of citicoline has been questioned in this indication, so it was considered necessary to undertake a systematic review and meta-analysis to evaluate whether citicoline is effective in the treatment of patients with TBI.

METHODS

A systematic search was performed on OVID-Medline, EMBASE, Google Scholar, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Ferrer databases, from inception to January 2021, to identify all published, unconfounded, comparative clinical trials of citicoline in the acute phase of head-injured patients- that is, treatment started during the first 24 h. We selected studies on complicated mild, moderate, and severe head-injured patients according to the score of the Glasgow Coma Scale (GCS). The primary efficacy measure was independence at the end of the scheduled clinical trial follow-up.

RESULTS

In total, 11 clinical studies enrolling 2771 patients were identified by the end. Under the random-effects model, treatment with citicoline was associated with a significantly higher rate of independence (RR, 1.18; 95% CI = 1.05-1.33; I2, 42.6%). The dose of citicoline or the administration route had no effect on outcomes. Additionally, no significant effects on mortality were found, and no safety concerns were noticed.

CONCLUSIONS

This meta-analysis indicates some beneficial effects of citicoline's increasing the number of independent patients with TBI. The most important limitation of our meta-analysis was the presumed heterogeneity of the studies included.

REGISTRATION

PROSPERO CRD42021238998.

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.

Role of Citicoline in the Management of Traumatic Brain Injury

Head injury is among the most devastating types of injury, specifically called Traumatic Brain Injury (TBI). There is a need to diminish the morbidity related with TBI and to improve the outcome of patients suffering TBI. Among the improvements in the treatment of TBI, neuroprotection is one of the upcoming improvements. Citicoline has been used in the management of brain ischemia related disorders, such as TBI. Citicoline has biochemical, pharmacological, and pharmacokinetic characteristics that make it a potentially useful neuroprotective drug for the management of TBI. A short review of these characteristics is included in this paper. Moreover, a narrative review of almost all the published or communicated studies performed with this drug in the management of patients with head injury is included. Based on the results obtained in these clinical studies, it is possible to conclude that citicoline is able to accelerate the recovery of consciousness and to improve the outcome of this kind of patient, with an excellent safety profile. Thus, citicoline could have a potential role in the management of TBI.

Citicoline as Adjuvant Therapy in Parkinson's Disease: A Systematic Review

PURPOSE

Parkinson disease (PD) medications are not readily available in all countries. Citicoline increases dopamine synthesis and inhibits dopamine uptake. This systematic review aims to synthesize current existing evidence on the efficacy of citicoline adjunctive therapy in improving PD symptoms.

METHODS

An extensive literature search of Scopus, Embase, PubMed, Cochrane Library, and Google Scholar was conducted for articles published on or before December 31, 2019. The studies were screened and selected by 2 independent reviewers. We included all studies that explored the efficacy of citicoline as an adjunct therapy in PD.

FINDINGS

A total of 7 studies (2 crossover, 3 randomized controlled, and 2 open prospective studies) were included. Despite the varied outcome tools, this review found that patients with PD who were taking citicoline had significant improvement in rigidity, akinesia, tremor, handwriting, and speech. Citicoline allowed effective reduction of levodopa by up to 50%. Significant improvement in cognitive status evaluation was also noted with citicoline adjunctive therapy.

IMPLICATIONS

Citicoline adjuvant therapy has beneficial effects as an adjuvant therapy in patients with PD. However, due to the heterogeneity of the studies, there is a need for more high-quality studies.

CDP-choline and galantamine, a personalized α7 nicotinic acetylcholine receptor targeted treatment for the modulation of speech MMN indexed deviance detection in healthy volunteers: a pilot study

RATIONALE

The combination of CDP-choline, an α7 nicotinic acetylcholine receptor (α7 nAChR) agonist, with galantamine, a positive allosteric modulator of nAChRs, is believed to counter the fast desensitization rate of the α7 nAChRs and may be of interest for schizophrenia (SCZ) patients. Beyond the positive and negative clinical symptoms, deficits in early auditory prediction-error processes are also observed in SCZ. Regularity violations activate these mechanisms that are indexed by electroencephalography-derived mismatch negativity (MMN) event-related potentials (ERPs) in response to auditory deviance.

OBJECTIVES/METHODS

This pilot study in thirty-three healthy humans assessed the effects of an optimized α7 nAChR strategy combining CDP-choline (500 mg) with galantamine (16 mg) on speech-elicited MMN amplitude and latency measures. The randomized, double-blinded, placebo-controlled, and counterbalanced design with a baseline stratification method allowed for assessment of individual response differences.

RESULTS

Increases in MMN generation mediated by the acute CDP-choline/galantamine treatment in individuals with low baseline MMN amplitude for frequency, intensity, duration, and vowel deviants were revealed.

CONCLUSIONS

These results, observed primarily at temporal recording sites overlying the auditory cortex, implicate α7 nAChRs in the enhancement of speech deviance detection and warrant further examination with respect to dysfunctional auditory deviance processing in individuals with SCZ.

Effects of CDP-choline administration on learning and memory in REM sleep-deprived rats

Cytidine 5-diphosphocholine (CDP-choline) administration has been shown to improve learning and memory deficits in different models of brain disorders. In this study, effects of CDP-choline on the well known negative effects of Rapid Eye Movements (REM) sleep deprivation on learning and memory were investigated. Sleep deprivation was induced by placing adult male Wistar albino rats on 6.5 cm diameter platforms individually for 96 h according to flower pot method. Learning and memory performances were evaluated using Morris Water Maze (MWM) test during the same period of time. Saline or CDP-choline (100 µmol/kg, 300 µmol/kg or 600 µmol/kg) was administered intraperitoneally 30 min prior to the onset of MWM experiments. On completion of behavioral tests, rats were decapitated and hippocampi were assayed for total and phosphorylated Ca²⁺/calmodulin-dependent protein kinase II (tCaMKII and pCaMKII, respectively) and total antioxidant capacity. We observed that while REM sleep deprivation had no effect on learning, it diminished the memory function, which was associated with decreased levels of pCaMKII and total antioxidant capacity in the hippocampus. CDP-choline treatment blocked the impairment in memory function of sleep-deprived rats and, increased pCaMKII levels and total antioxidant capacity. These data suggest that CDP-choline reduces REM sleep deprivation-induced impairment in memory, at least in part, by counteracting the disturbances in biochemical and molecular biological parameters.

Exploring the Substrate Scope of the Bacterial Phosphocholine Transferase AnkX for Versatile Protein Functionalization

Site-specific protein functionalization has become an indispensable tool in modern life sciences. Here, tag-based enzymatic protein functionalization techniques are among the most versatilely applicable approaches. However, many chemo-enzymatic functionalization strategies suffer from low substrate scopes of the enzymes utilized for functional labeling probes. We report on the wide substrate scope of the bacterial enzyme AnkX towards derivatized CDP-choline analogues and demonstrate that AnkX-catalyzed phosphocholination can be used for site-specific one- and two-step protein labeling with a broad array of different functionalities, displaying fast second-order transfer rates of 5×10² to 1.8×10⁴  m^-1  s^-1 . Furthermore, we also present a strategy for the site-specific dual labeling of proteins of interest, based on the exploitation of AnkX and the delabeling function of the enzyme Lem3. Our results contribute to the wide field of protein functionalization, offering an attractive chemo-enzymatic tag-based modification strategy for in vitro labeling.

Combining CDP-choline and galantamine: Effects of a selective α7 nicotinic acetylcholine receptor agonist strategy on P50 sensory gating of speech sounds in healthy volunteers

BACKGROUND

Schizophrenia (SCZ) patients and relatives have deficits in early cortical sensory gating (SG) typically measured by suppression of electroencephalography-derived P50 event-related potentials (ERPs) in a conditioning-testing (S₁-S₂) paradigm. Associated with alpha 7 nicotinic acetylcholine receptor (α7 nAChR) dysfunction and shown to be improved with nicotine and α7 nAChR agonists, SG has recently been shown to be improved in low P50 suppressing SCZ patients following acute CDP-choline treatment.

AIMS

This pilot study in healthy humans assessed the SG effects of an α7 nAChR strategy combining CDP-choline with galantamine, a positive allosteric modulator (PAM) of nAChRs, aimed at increasing and prolonging nicotinic receptor activity.

METHODS

The combined effect of CDP-choline (500 mg) and galantamine (16 mg) on speech P50 gating indices rP50 (S₂/S₁) and dP50 (S₁-S₂) was examined in 30 healthy participants stratified into low and high baseline P50 suppressors in a randomized, double-blind, placebo-controlled and counterbalanced design.

RESULTS

In low suppressors, CDP-choline/galantamine (vs. placebo) improved rP50 and dP50 gating, and reduced S₂P50 amplitudes. No P50 gating effects were observed in high suppressors; however, CDP-choline/galantamine (vs. placebo) increased their S₂P50 amplitudes.

CONCLUSION

Findings from this pilot study with CDP-choline/galantamine in a healthy, SCZ-like surrogate deficient gating sample are consistent with the association of α7 nAChR mechanisms in SG impairment in SCZ and support further research trials with CDP-choline and galantamine targeting sensory processes.

Combining CDP-choline and galantamine, an optimized α7 nicotinic strategy, to ameliorate sensory gating to speech stimuli in schizophrenia

Neural α7 nicotinic acetylcholine receptor (nAChR) expression and functioning deficits have been extensively associated with cognitive and early sensory gating (SG) impairments in schizophrenia (SCZ) patients and their relatives. SG, the suppression of irrelevant and redundant stimuli, is measured in a conditioning-testing (S₁-S₂) paradigm eliciting electroencephalography-derived P50 event-related potentials (ERPs), the S₂ amplitudes of which are typically suppressed relative to S₁. Despite extensive reports of nicotine-related improvements and several decades of research, an efficient nicotinic treatment has yet to be approved for SCZ. Following reports of SG improvements in low P50 suppressing SCZ patients and healthy participants with the α7 agonist, CDP-choline, this pilot study examined the combined modulatory effect of CDP-choline (500 mg) and galantamine (16 mg), a nAChR positive allosteric modulator and acetylcholinesterase inhibitor, on SG to speech stimuli in twenty-four SCZ patients in a randomized, double-blind and placebo-controlled design. As expected, in low P50 suppressors CDP-choline/galantamine (vs. Placebo) improved rP50 and dP50 scores by increasing inhibitory mechanisms as reflected by S₂P50 amplitude reductions. Results also suggest a moderating role for auditory verbal hallucinations in treatment response. These preliminary findings provide supportive evidence for the involvement of α7 nAChR activity in speech gating in SCZ and support additional trials, examining different dose combinations and repeated doses of this optimized and personalized targeted α7 cholinergic treatment for SG dysfunction in subgroups of SCZ patients.

CDP-choline accumulation in breast and colorectal cancer cells treated with a GSK-3-targeting inhibitor

Purpose

Glycogen synthase kinase 3 (GSK3) is a key controlling element of many cellular processes including cell-cycle progression and recent studies suggest that GSK3 is a potential anticancer target. Changes in glucose metabolism associated with GSK3 inhibition may impact on lipid synthesis, whilst lipid metabolites can act as molecular response markers.

Methods

Here, SKBr3 breast and HCT8 colorectal cancer cells were treated with the GSK3 inhibitor SB216763, and [¹⁴C (U)] glucose and [³H] choline incorporation into lipids was determined. Cell extracts from treated cells were subject to ³¹P NMR spectroscopy.

Results

SB216763 treatment decreased choline incorporation into lipids and caused an accumulation of CDP-choline which was accompanied by decreased conversion of glucose into lipid components.

Conclusion

SB216763 profoundly inhibits phospholipid synthesis in cancer cells which demonstrate accumulation of CDP-choline detectable by ³¹P NMR spectroscopy. Metabolic changes in lipid metabolism present potential response markers to drugs targeting GSK3.

Citicoline (CDP-choline) add-on therapy to risperidone for treatment of negative symptoms in patients with stable schizophrenia: A double-blind, randomized placebo-controlled trial

OBJECTIVE

We aimed to evaluate the efficacy and tolerability of citicoline add-on therapy in treatment of negative symptoms in patients with stable schizophrenia.

METHODS

In a double-blind and placebo-controlled study, patients with stable schizophrenia (DSM-5) were randomized to receive either 2,500 mg/day citicoline or placebo in addition to risperidone for 8 weeks. The patients were assessed using the positive and negative syndrome scale (PANSS), the extrapyramidal symptom rating scale (ESRS), and Hamilton depression rating scale (HDRS). The primary outcome was the difference in PANSS negative subscale score reduction from baseline to week 8 between the citicoline and the placebo groups.

RESULTS

Sixty-six individuals (out of 73 enrolled) completed the trial. The citicoline group demonstrated significantly greater improvement in negative scores, F(1.840, 118.360) = 8.383, p = .001, as well as general psychopathology, F(1.219, 78.012) = 6.636, p = .008; change in general psychopathology did not remain significant after adjustment, and total PANSS scores, F(1.633, 104.487) = 15.400, p < .001, compared with the placebo. HDRS scores and its changes, ESRS score, and frequency of other side effects were not significantly different between the two groups.

CONCLUSIONS

Citicoline add-on therapy to risperidone can effectively improve the primary negative symptoms of patients with schizophrenia.

Assessing the acute effects of CDP-choline on sensory gating in schizophrenia: A pilot study

Deficient sensory gating (SG) in schizophrenia is associated with functional outcome and offers a therapeutic target as it is linked to the altered function/expression of the α7 nicotinic acetylcholine receptors (nAChRs). This study analyzed the effects of citicoline (CDP-choline), a supplement with α7 nAChRs agonist properties, on SG in a sample of schizophrenia (SZ) patients. Using a randomized, placebo-controlled, double-blind design the dose-dependent (500 mg, 1000 mg, 2000 mg) and baseline-dependent (deficient versus normal suppressors) effects of CDP-choline on SG were examined using the P50 event-related potential (ERP) index of SG. Overall analysis failed to demonstrate treatment effects but CDP-choline improved SG (500 mg) in the deficient SZ subgroup by increasing suppression of the S2 P50 amplitude. These findings tentatively support α7 nAChR dysfunction in the expression of SG deficits and suggest further trials to assess the effects of sustained α7 nAChR activation on SG with low doses of CDP-choline.

[Pharmacological therapeutic intervention in mild cognitive impairment]

Mild cognitive impairment (MCI) is a syndrome encompassing affective and behavioural symptoms and various subtypes. MCI is a heterogeneous clinical entity with varied causes (degenerative, vascular, psychiatric, non-neurological disorders), and there is wide variation in symptoms and clinical course. There are multiple causes and consequently various treatments can be applied and should be combined with non-pharmacological measures. This article describes both preventive and therapeutic pharmacological interventions: control of vascular risk factors, avoidance of iatrogeny, use of nutraceuticals, CDP-choline, and Ginkgo biloba EGb 761^®, and improvement in sense organs.

Citicoline for Acute Ischemic Stroke: A Systematic Review and Formal Meta-analysis of Randomized, Double-Blind, and Placebo-Controlled Trials

BACKGROUND

Citicoline is a drug approved for the treatment of acute ischemic stroke. Although evidence of its efficacy has been reported, recently published results of a large placebo-controlled clinical trial did not show differences. This study aims to assess whether starting citicoline treatment within 14 days after stroke onset improves the outcome in patients with acute ischemic stroke, as compared with placebo.

METHODS

A systematic search was performed to identify all published, unconfounded, randomized, double-blind, and placebo-controlled clinical trials of citicoline in acute ischemic stroke.

RESULTS

Ten randomized clinical trials met our inclusion criteria. The administration of citicoline was associated with a significant higher rate of independence, independently of the method of evaluation used (odds ratio [OR] 1.56, 95% confidence interval [CI] = 1.12-2.16 under random effects; OR 1.20, 95% CI = 1.06-1.36 under fixed effects). After studying the cumulative meta-analysis, and with the results obtained with the subgroup of patients who were not treated with recombinant tissue plasminogen activator (rtPA) (OR 1.63, 95% CI = 1.18-2.24 under random effects; OR 1.42, 95% CI = 1.22-1.66 under fixed effects), our hypothesis of dilution of the effect of citicoline was confirmed. When we analyzed the effect of citicoline in patients who were not treated with rtPA and were receiving the highest dose of citicoline started in the first 24 hours after onset, based on more recent trials, there was no heterogeneity, and the size of the effect has an OR of 1.27 (95% CI = 1.05-1.53).

CONCLUSIONS

This systematic review supports some benefits of citicoline in the treatment of acute ischemic stroke. But, on top of the best treatment available (rtPA), citicoline offers a limited benefit.

Efficient synthesis of cytidine diphosphate choline (CDP-choline) and its analogs

An efficient P(V)-N activation approach for the synthesis of cytidine diphosphate choline (CDP-choline) and related ribo- and deoxyribonucleotide analogs has been established.

CDP-choline modulates matrix metalloproteinases in rat sciatic injury

BACKGROUND

CDP-choline (cytidine-5'-diphosphocholine) improves functional recovery, promotes nerve regeneration, and decreases perineural scarring in rat peripheral nerve injury. The aim of the present study was to investigate the mechanism of action of CDP-choline with regard to matrix metalloproteinase (MMP) activity in the rat-transected sciatic nerve injury model.

MATERIALS AND METHODS

Male Wistar rats were randomized into Sham, Saline, and CDP-choline groups. Rats in Sham group received Sham surgery, whereas rats in Saline and CDP-choline groups underwent right sciatic nerve transection followed by immediate primary saturation and injected intraperitoneally with 0.9% NaCl (1 mL/kg) and CDP-choline (600 μg/kg), respectively. Sciatic nerve samples were obtained 1, 3, and 7 d after the surgery and analyzed for levels and activities of MMP-2 and MMP-9, levels of tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-3, and axonal regeneration.

RESULTS

CDP-choline treatment decreased the levels and activities of MMP-2 and MMP-9, whereas increasing levels of TIMP-1 and TIMP-3 significantly on the third and seventh day after injury compared to Saline group. In addition, CDP-choline administration resulted in new axon formation and formation and advancement of myelination on newly formed islets (compartments) of axonal regrowth.

CONCLUSIONS

Our data show, for the first time, that CDP-choline modulates MMP activity and promotes the expression of TIMPs to stimulate axonal regeneration. These data help to explain one mechanism by which CDP-choline provides neuroprotection in peripheral nerve injury.

Central injection of CDP-choline suppresses serum ghrelin levels while increasing serum leptin levels in rats

In this study we aimed to test central administration of CDP-choline on serum ghrelin, leptin, glucose and corticosterone levels in rats. Intracerebroventricular (i.c.v.) 0.5, 1.0 and 2.0 µmol CDP-choline and saline were administered to male Wistar-Albino rats. For the measurement of serum leptin and ghrelin levels, blood samples were obtained baseline and at 5, 15, 30, 60 and 120 min following i.c.v. CDP-choline injection. Equimolar doses of i.c.v. choline (1.0 µmol) and cytidine (1.0 µmol) were administered and measurements were repeated throughout the second round of the experiment. Atropine (10 µg) and mecamylamine (50 µg) were injected intracerebroventricularly prior to CDP-choline and measurements repeated in the third round of the experiment. After 1 µmol CDP-choline injection, serum ghrelin levels were suppressed significantly at 60 min (P=0.025), whereas serum leptin levels were increased at 60 and 120 min (P=0.012 and P=0.017 respectively). CDP-choline injections also induced a dose- and time-dependent increase in serum glucose and corticosterone levels. The effect of choline on serum leptin and ghrelin levels was similar with CDP-choline while no effect was seen with cytidine. Suppression of serum ghrelin levels was eliminated through mecamylamine pretreatment while a rise in leptin was prevented by both atropine and mecamylamine pretreatments. In conclusion; centrally injected CDP-choline suppressed serum ghrelin levels while increasing serum leptin levels. The observed effects following receptor antagonist treatment suggest that nicotinic receptors play a role in suppression of serum ghrelin levels,whereas nicotinic and muscarinic receptors both play a part in the increase of serum leptin levels.

Neurocognitive effects of acute choline supplementation in low, medium and high performer healthy volunteers

Novel pharmacological treatments targeting alpha 7 nicotinic acetylcholine receptor (α7 nAChR) hypofunction in schizophrenia have shown mixed success in ameliorating cognitive impairments associated with this disorder. Choline, a selective agonist at α7 receptors is increased with oral administration of cytidine 5'-diphosphocholine (CDP-choline), the cognitive effects of which were assessed in healthy volunteers. Using the CogState test battery, behavioral performance in schizophrenia-relevant cognitive domains was assessed in 24 male participants following a single low (500mg) and moderate (1000mg) dose of CDP-choline. Relative to placebo, CDP-choline improved processing speed, working memory, verbal learning, verbal memory, and executive function in low baseline performers, while exerting no effects in medium baseline performers, and diminishing cognition in high baseline performers. Dose effects varied with cognitive domain but were evident with both the 500mg and 1000mg doses. These preliminary findings of cognitive enhancement in relatively impaired performers are consistent with the α7 receptor mechanism and support further trials with CDP-choline as a potential pro-cognitive strategy for cognitive impairment in schizophrenia.

CDP-choline: effects of the procholine supplement on sensory gating and executive function in healthy volunteers stratified for low, medium and high P50 suppression

Diminished auditory sensory gating and associated neurocognitive deficits in schizophrenia have been linked to altered expression and function of the alpha-7 nicotinic acetycholinergic receptor (α7 nAChR), the targeting of which may have treatment potential. Choline is a selective α7 nAChR agonist and the aim of this study was to determine whether cytidine 5'-diphosphocholine (CDP-choline), or citicoline, a dietary source of choline, increases sensory gating and cognition in healthy volunteers stratified for gating level. In a randomized, placebo-controlled, double-blind design involving acute administration of low, moderate doses (500 mg, 1000 mg) of CDP-choline, 24 healthy volunteers were assessed for auditory gating as indexed by suppression of the P50 event-related potential (ERP) in a paired-stimulus (S1, S2) paradigm, and for executive function as measured by the Groton Maze Learning Task (GMLT) of the CogState Schizophrenia Battery. CDP-choline improved gating (1000 mg) and suppression of the S2 P50 response (500 mg, 1000 mg), with the effects being selective for individuals with low gating (suppression) levels. Tentative support was also shown for increased GMLT performance (500 mg) in low suppressors. These preliminary findings with CDP-choline in a healthy, schizophrenia-like surrogate sample are consistent with a α7 nAChR mechanism and support further trials with choline as a pro-cognitive strategy.

CDP-choline attenuates scopolamine induced disruption of prepulse inhibition in rats: involvement of central nicotinic mechanism

It has been shown that cholinergic system plays an important role in schizophrenia-associated cognitive deficits, therefore cholinergic drugs are novel targets for the treatment of cognitive deficits seen in schizophrenia. We aimed to test the effects of CDP-choline on sensorimotor gating functioning, which is an important function for the integration of sensory and cognitive information processing and the execution of appropriate motor responses. In this study, prepulse inhibition (PPI) of the acoustic startle reflex was used to test the sensorimotor gating functioning, and the effects of CDP-choline on scopolamine induced PPI disruption were evaluated in rats. Furthermore, the contribution of the cholinergic mechanism in these effects was determined. CDP-choline (75, 250, 500mg/kg) by itself had no effect on the PPI in naïve animals. Scopolamine (0.4mg/kg; s.c.) significantly decreased the PPI levels and intraperitoneal administration of CDP-choline (250mg/kg) attenuated the effects of scopolamine. A non-specific nicotinic receptor antagonist, mecamylamine and an alpha 7 nicotinic receptor (α7-nAChR) antagonist, methyllycaconitine were used to investigate the mechanism underlying the effects of CDP-choline. Mecamylamine (3mg/kg; s.c.), and methyllycaconitine (10μg; i.c.v.) completely blocked the reversal effects of CDP-choline on scopolamine induced disruption of PPI. These results demonstrate that exogenous administration of CDP-choline attenuates scopolamine induced PPI disruption and show that the activation of central α7-nAChR may play a critical role in this effect.

Centrally administered CDP-choline induced cardiovascular responses are mediated by activation of the central phospholipase-prostaglandin signaling cascade

The present study was designed to determine the involvement of central prostaglandin synthesis on the pressor and bradycardic effect of cytidine 5'-diphosphocholine (CDP-choline). Intracerebroventricular (i.c.v.) administration of CDP-choline was made and blood pressure and heart rate were recorded in male Sprague Dawley rats throughout this study. Microdialysis and immunohistochemical studies were performed to measure extracellular total prostaglandin concentration and to show cyclooxygenase-1 and -2 (COX-1 and -2) immunoreactivities, respectively, in the posterior hypothalamic area. Moreover, rats were pretreated (i.c.v) with mepacrine [a phospholipase A2 (PLA2) inhibitor], ibuprofen [a nonselective COX inhibitor], neomycine [a phospholipase C (PLC) inhibitor] or furegrelate [a thromboxane A2 (TXA2) synthesis inhibitor] 5 min prior to the injection of CDP-choline to determine the effects of these inhibitors on cardiovascular responses to CDP-choline. Control rats were pretreated (i.c.v) with saline. CDP-choline caused a dose- and time-dependent increase in blood pressure and decrease in heart rate. Immunohistochemical studies showed that CDP-choline increased COX-1 and -2 immunoreactivities in the posterior hypothalamic area. CDP-choline also elevated hypothalamic extracellular total prostaglandin concentration by 62%, as shown in microdialysis studies. Mepacrine or ibuprofen pretreatments almost completely blocked the pressor and bradycardic responses to CDP-choline while neomycine or furegrelate partially attenuated the drug-induced cardiovascular effects. The results suggest that CDP-choline may stimulate prostaglandin synthesis through the activation of PLA2, cyclooxygenases (COX-1 and -2) and prostaglandins and at least TXA2, may mediate the drug׳s cardiovascular effects.

The effect of centrally injected CDP-choline on respiratory system; involvement of phospholipase to thromboxane signaling pathway

CDP-choline is an endogenous metabolite in phosphatidylcholine biosynthesis. Exogenous administration of CDP-choline has been shown to affect brain metabolism and to exhibit cardiovascular, neuroendocrine neuroprotective actions. On the other hand, little is known regarding its respiratory actions and/or central mechanism of its respiratory effect. Therefore the current study was designed to investigate the possible effects of centrally injected CDP-choline on respiratory system and the mediation of the central cholinergic receptors and phospholipase to thromboxane signaling pathway on CDP-choline-induced respiratory effects in anaesthetized rats. Intracerebroventricularly (i.c.v.) administration of CDP-choline induced dose- and time-dependent increased respiratory rates, tidal volume and minute ventilation of male anaesthetized Spraque Dawley rats. İ.c.v. pretreatment with atropine failed to alter the hyperventilation responses to CDP-choline whereas mecamylamine, cholinergic nicotinic receptor antagonist, mepacrine, phospholipase A2 inhibitor, and neomycin phospholipase C inhibitor, blocked completely the hyperventilation induced by CDP-choline. In addition, central pretreatment with furegrelate, thromboxane A2 synthesis inhibitor, also partially blocked CDP-choline-evoked hyperventilation effects. These data show that centrally administered CDP-choline induces hyperventilation which is mediated by activation of central nicotinic receptors and phospholipase to thromboxane signaling pathway.

Citicoline (CDP-choline) protects myocardium from ischemia/reperfusion injury via inhibiting mitochondrial permeability transition

AIMS

Oxidative stress emerges after reperfusion of an organ following an ischemic period and results in tissue damage. In the heart, an amplified generation of reactive oxygen species and a significant Ca(2+) accumulation cause ventricular arrhythmias and mitochondrial dysfunction. This occurs in consequence of increased non-specific permeability. A number of works have shown that permeability transition is a common substrate that underlies the reperfusion-induced heart injury. The aim of this work was to explore the possibility that CDP-choline may circumvent heart damage and mitochondrial permeability transition.

MAIN METHODS

Rats were injected i.p. with CDP-choline at 20 mg/kg body weight. Heart electric behavior was followed during a closure/opening cycle of the left coronary descendent artery. Heart mitochondria were isolated from rats treated with CDP-choline, and their function was evaluated by analyzing Ca(2+) movements, achievement of a high level of the transmembrane potential, and respiratory control. Oxidative stress was estimated following the activity of the enzymes cis-aconitase and superoxide dismutase, as well as the disruption of mitochondrial DNA.

KEY FINDINGS

This study shows that CDP-choline avoided ventricular arrhythmias and drop of blood pressure. Results also show that mitochondria, isolated from CDP-choline-treated rats, maintained selective permeability, retained accumulated Ca(2+), an elevated value of transmembrane potential, and a high ratio of respiratory control. Furthermore, activity of cis-aconitase enzyme and mDNA structure were preserved.

SIGNIFICANCE

This work introduces CDP-choline as a useful tool to preserve heart function from reperfusion damage by inhibiting mitochondrial permeability transition.

Citicoline (CDP-choline) increases Sirtuin1 expression concomitant to neuroprotection in experimental stroke

CDP-choline has shown neuroprotective effects in cerebral ischemia. In humans, although a recent trial International Citicoline Trial on Acute Stroke (ICTUS) has shown that global recovery is similar in CDP-choline and placebo groups, CDP-choline was shown to be more beneficial in some patients, such as those with moderate stroke severity and not treated with t-PA. Several mechanisms have been proposed to explain the beneficial actions of CDP-choline. We have now studied the participation of Sirtuin1 (SIRT1) in the neuroprotective actions of CDP-choline. Fischer rats and Sirt1⁻/⁻ mice were subjected to permanent focal ischemia. CDP-choline (0.2 or 2 g/kg), sirtinol (a SIRT1 inhibitor; 10 mg/kg), and resveratrol (a SIRT1 activator; 2.5 mg/kg) were administered intraperitoneally. Brains were removed 24 and 48 h after ischemia for western blot analysis and infarct volume determination. Treatment with CDP-choline increased SIRT1 protein levels in brain concomitantly to neuroprotection. Treatment with sirtinol blocked the reduction in infarct volume caused by CDP-choline, whereas resveratrol elicited a strong synergistic neuroprotective effect with CDP-choline. CDP-choline failed to reduce infarct volume in Sirt1⁻/⁻ mice. Our present results demonstrate a robust effect of CDP-choline like SIRT1 activator by up-regulating its expression. Our findings suggest that therapeutic strategies to activate SIRT1 may be useful in the treatment of stroke. Sirtuin 1 (SIRT1) is implicated in a wide range of cellular functions. Regarding stroke, there is no direct evidence. We have demonstrated that citicoline increases SIRT1 protein levels in brain concomitantly to neuroprotection. Citicoline fails to reduce infarct volume in Sirt1⁻/⁻ mice. Our findings suggest that therapeutic strategies acting on SIRT1 may be useful in the treatment of stroke.