Publications by authors named "Eri Nakazaki"

5 Publications

  • Page 1 of 1

Citicoline and Memory Function in Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

J Nutr 2021 May 12. Epub 2021 May 12.

Research & Innovation Center, Kyowa Hakko Bio Co., Ltd, Tsukuba, Ibaraki, 305-0841, Japan.

Background: Supplementation of citicoline (CDP-choline), a naturally occurring mononucleotide, has shown beneficial effects on memory function and behavior in populations with a wide range of impairments. However, few studies have investigated its effect in healthy older populations.

Objective: The objective of this study was to investigate the effects of citicoline (Cognizin®), on memory in healthy elderly populations with age-associated memory impairment (AAMI).

Methods: A total of 100 healthy men and women aged between 50 and 85 y with AAMI participated in this randomized, double-blind, placebo-controlled trial. Participants were randomized to receive placebo (n = 51) or citicoline (n = 49; 500 mg/d) for 12 wk. Memory function was assessed at baseline and end of the intervention (12 wk) using computerized tests (Cambridge Brain Sciences, Ontario, Canada). Safety measurements included adverse events query, body weight, blood pressure, and hematology and metabolic panel. Intent-to-treat analysis was conducted using ANCOVA for the primary and secondary outcome variables with Bonferroni correction for multiple comparisons.

Results: A total of 99 out of 100 participants completed the study in its entirety. After the 12-wk intervention, participants supplemented with citicoline showed significantly greater improvements in secondary outcomes of episodic memory (assessed by the Paired Associate test), compared with those on placebo (mean: 0.15 vs. 0.06, respectively, P = 0.0025). Composite memory (secondary outcome), calculated using the scores of 4 memory tests, also significantly improved to a greater extent following citicoline supplementation (mean: 3.78) compared with placebo (mean: 0.72, P = 0.0052).

Conclusions: Dietary supplementation of citicoline for 12 wk improved overall memory performance, especially episodic memory, in healthy older males and females with AAMI. The findings suggest that regular consumption of citicoline may be safe and potentially beneficial against memory loss due to aging. This trial was registered at as NCT03369925.
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May 2021

Combined citicoline and docosahexaenoic acid treatment improves cognitive dysfunction following transient brain ischemia.

J Pharmacol Sci 2019 Apr 20;139(4):319-324. Epub 2019 Feb 20.

Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8678, Japan. Electronic address:

Phospholipids are structural components of cellular membranes that play important roles as precursors for various signaling pathways in modulating neuronal membrane function and maintenance of the intracellular environment. Phosphatidylcholine (PtdCho) is the most abundant cellular phospholipid. Citicoline and docosahexaenoic acid (DHA) are essential intermediates in the synthesis of PtdCho. Both PtdCho intermediates have independently shown neuroprotective effects in cerebral ischemia, but their combined effect is unknown. This study aimed to investigate the combined effect of oral citicoline and DHA treatment on improvement of cognitive deficits following cerebral ischemia using a 20-min bilateral common carotid artery occlusion (BCCAO) mouse model. BCCAO ischemic mice were treated for a total of 11 days with a combination of citicoline (40 mg/kg body weight/day) and DHA (300 mg/kg body weight/day) or each alone. Combined citicoline and DHA synergistically and significantly improved learning and memory ability of ischemic mice compared with either alone. Further, citicoline and DHA treatment significantly prevented neuronal cell death, and slightly increased DHA-containing PtdCho in the hippocampus, albeit not significantly. Taken together, these findings suggest that combined citicoline and DHA treatment may have synergistic benefits for partially improving memory deficits following transient brain ischemia.
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April 2019

The Effect of Citicoline Supplementation on Motor Speed and Attention in Adolescent Males.

J Atten Disord 2019 01 15;23(2):121-134. Epub 2015 Jul 15.

1 University of Utah, Salt Lake City, UT, USA.

Objective: This study assessed the effects of citicoline, a nutraceutical, on attention, psychomotor function, and impulsivity in healthy adolescent males.

Method: Seventy-five healthy adolescent males were randomly assigned to either the citicoline group ( n = 51 with 250 or 500 mg citicoline) or placebo ( n = 24). Participants completed the Ruff 2&7 Selective Attention Test, Finger Tap Test, and the Computerized Performance Test, Second Edition (CPT-II) at baseline and after 28 days of supplementation.

Results: Individuals receiving citicoline exhibited improved attention ( p = 0.02) and increased psychomotor speed ( p = 0.03) compared with those receiving placebo. Higher weight-adjusted dose significantly predicted increased accuracy on an attention task ( p = 0.01), improved signal detectability on a computerized attention task ( p = 0.03), and decreased impulsivity ( p = 0.01).

Discussion: Adolescent males receiving 28 days of Cognizin® citicoline showed improved attention and psychomotor speed and reduced impulsivity compared to adolescent males who received placebo.
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January 2019

Proteomic study of granulocytic differentiation induced by apigenin 7-glucoside in human promyelocytic leukemia HL-60 cells.

Eur J Nutr 2013 Feb 24;52(1):25-35. Epub 2011 Nov 24.

Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.

Background: Nutritional factors is one of the most important regulators in the progression of cancer. Some dietary elements promote the growth of cancer but others, such as plant-derived compounds, may reverse this process.

Purpose: We tried to investigate yet another approach of cancer prevention through cancer cell differentiation, using a common non-mutagenic flavonoid apigenin 7-glucoside.

Methods: HL-60 cells were treated with or without apigenin 7-glucoside. Cell proliferation was measured by MTT assay, and the cell cycle distribution was estimated by propidium iodide staining of DNA. To determine cellular differentiation, cell surface differentiation markers CD11b and CD14 were used. Two-dimensional gel electrophoresis was then performed to identify proteins that may be important in HL-60 cell differentiation following apigenin 7-glucoside treatment.

Results: Apigenin 7-glucoside inhibited HL-60 cell growth, dose- and time-dependently, but did not cause apoptosis. The distribution of cells at different stages in the cell cycle indicated an accumulation of treated cells in G(2)/M phase. Moreover, apigenin 7-glucoside induced granulocytic differentiation of HL-60 cells. Ten proteins that might play essential role in granulocytic differentiation were identified by proteomics.

Conclusions: A complete understanding of the preventive effects of plant-based diet on cancer depends on the mechanisms of action of different plant components on processes. We hope these findings may contribute to the understandings of the different approaches for chemoprevention of cancer.
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February 2013

Apigetrin induces erythroid differentiation of human leukemia cells K562: proteomics approach.

Mol Nutr Food Res 2011 May 11;55 Suppl 1:S93-S102. Epub 2011 Apr 11.

Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki, Japan.

Scope: Induction of cancer-cell differentiation is an alternative approach for cancer chemotherapy. There are numerous studies that diets containing an abundance of fruits and vegetables have protection against cancers, and the main agents thought to provide such protective effect are flavonoids. In this study we used apigetrin as a possible cell differentiation inducer and chronic leukemia cells K562 for their pluripotent differentiating potency.

Methods And Results: Prolonged treatment with 75 μM apigetrin induced erythroid differentiation of K562 cells with specific marker glycophorin A expression and fetal hemoglobin synthesis in treated cells, which was accompanied with G(2) /M arrest. Proteomics data revealed the downregulation of several proteins expression involved in cell cycle regulation, protein synthesis and nuclear import and export of signaling molecules.

Conclusion: This is the first evidence that natural compound apigetrin may induce cancer cell differentiation thus could be one of the possible explanations of its antitumor effects.
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May 2011