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Takeki Hamasaki Last modified date:2022.06.20

Associate Professor / Department of Bioscience and Biotechnology
Faculty of Agriculture

Administration Post

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Homepage of Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University .
Academic Degree
Doctor of Agriculture
Country of degree conferring institution (Overseas)
Field of Specialization
Analysis of bioactivity of metal nanoparticles and antioxidants
Total Priod of education and research career in the foreign country
Outline Activities
Activity on study: Development of functional waters and metal nanoparticles for anti-oxidation, anti-life style-related diseases and anti-allergy.
Research Interests
  • Analysis of beneficial effects of functional water
    keyword : functional water, antioxidant, diabetes, cancer,
  • Study for beneficial effect of metal nanoparticles.
    keyword : nanoparticles,
Academic Activities
1. Takeki Hamasaki, Harada Gakuro, Noboru Nakamichi, Shigeru Kabayama, Kiichiro Teruya, Fugetsu, Bunshi, Gong, Wei, Sakata, Ichiro, Sanetaka Shirahata, Electrochemically reduced water exerts superior reactive oxygen species scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water
, PLoS ONE, 10.1371/journal.pone.0171192, 12, 2, 2017.02, Electrochemically reduced water (ERW) is produced near a cathode during electrolysis and exhibits an alkaline pH, contains richly dissolved hydrogen, and contains a small amount of platinum nanoparticles. ERW has reactive oxygen species (ROS)-scavenging activity and recent studies demonstrated that hydrogen-dissolved water exhibits ROS-scavenging activity. Thus, the antioxidative capacity of ERW is postulated to be dependent on the presence of hydrogen levels; however, there is no report verifying the role of dissolved hydrogen in ERW. In this report, we clarify whether the responsive factor for antioxidative activity in ERW is dissolved hydrogen. The intracellular ROS scavenging activity of ERW and hydrogen-dissolved water was tested by both fluorescent stain method and immuno spin trapping assay. We confirm that ERW possessed electrolysis intensity-dependent intracellular ROS-scavenging activity, and ERW exerts significantly superior ROS-scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water. ERW retained its ROS-scavenging activity after removal of dissolved hydrogen, but lost its activity when autoclaved. An oxygen radical absorbance capacity assay, the 2,2-diphenyl-1-picrylhydrazyl assay and chemiluminescence assay could not detect radical-scavenging activity in both ERW and hydrogen-dissolved water. These results indicate that ERW contains electrolysis-dependent hydrogen and an additional antioxidative factor predicted to be platinum nanoparticles..
2. Takeki Hamasaki, Noboru Nakamichi, Kiichiro Teruya, Sanetaka Shirahata, Removal Efficiency of Radioactive Cesium and Iodine Ions by a Flow-Type Apparatus Designed for Electrochemically Reduced Water Production., PLoS ONE, 10.1371/journal.pone.0102218, 9, 7, 2014.06, The Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 attracted people's attention, with anxiety over possible radiation hazards. Immediate and long-term concerns are around protection from external and internal exposure by the liberated radionuclides. In particular, residents living in the affected regions are most concerned about ingesting contaminated foodstuffs, including drinking water. Efficient removal of radionuclides from rainwater and drinking water has been reported using several pot-type filtration devices. A currently used flow-type test apparatus is expected to simultaneously provide radionuclide elimination prior to ingestion and protection from internal exposure by accidental ingestion of radionuclides through the use of a micro-carbon carboxymethyl cartridge unit and an electrochemically reduced water production unit, respectively. However, the removability of radionuclides from contaminated tap water has not been tested to date. Thus, the current research was undertaken to assess the capability of the apparatus to remove radionuclides from artificially contaminated tap water. The results presented here demonstrate that the apparatus can reduce radioactivity levels to below the detection limit in applied tap water containing either 300 Bq/kg of 137Cs or 150 Bq/kg of 125I. The apparatus had a removal efficiency of over 90% for all concentration ranges of radio-cesium and -iodine tested. The results showing efficient radionuclide removability, together with previous studies on molecular hydrogen and platinum nanoparticles as reactive oxygen species scavengers, strongly suggest that the test apparatus has the potential to offer maximum safety against radionuclide-contaminated foodstuffs, including drinking water. Removal Efficiency of Radioactive Cesium and Iodine Ions by a Flow-Type Apparatus Designed for Electrochemically Reduced Water Production. Available from: [accessed May 2, 2017]..
3. Hamasaki T, Aramaki S, Imada T, Teruya K, Kabayama S, Katakura Y, Otubo K, Morisawa S, Shirahata S. , Induction of caspase-3-dependent apoptosis by electrolyzed reduced water/platinum nanoparticles in cancer cells., Cell Technology for Cell Products 87-89. (2007)., 2007.07.
4. Hamasaki T, Kashiwagi T, Aramaki S, Imada T, Komatsu T, Li Y, Teruya K, Katakura Y, Kabayama S, Otsubo K, Morisawa S, Shirahata S., Suppression of cell growth by platinum nanocolloids as scavengers against reactive oxygen species. , Animal Cell Technology Meets Genomics 249-251. (2005), 249-251, 2005.07.
1. Sanetaka Shirahata, Takeki Hamasaki, Kiichiro Teruya, Newly found activities of electrochemically reduced water, The 27th Annual Meeting of Japanese Association for Animal Cell Technology, 2014.11, Electrochemically reduced water (ERW) produced near the cathode by the electrolysis of water contains hydrogen molecules and small amounts of mineral nanoparticles including platinum nanoparticles (Pt NPs), both of which have drawn much attention as newly recognized antioxidative cellular redox regulation factors. We are currently collaborating with the Karolinska Institutet and examining the suppressive effect of hydrogen molecules dissolved in ERW on aging associated neuro-inflammation. Here we report our recent knowledge about ERW, hydrogen molecules, hydrogen atoms and mineral nanoparticles.
We have demonstrated that ERW exhibited antitumor, antidiabetic and antineuronal cell death effects when tested with cultured cells and animal disease models. We have been devoting our effort searching for the substances responsible for these efficacies. At present, we are focusing on Pt Nps or dissolved hydrogen. Although we have reported previously that Pt Nps possess intracellular antioxidative effects, we now report our recent findings that an intracellular antioxidative effect was observed even with an extremely low concentration of Pt Nps. Researches for the molecular hydrogen dissolved in ERW are highly active and the reports in this area exceed more than 200 articles. However, the mechanisms for antioxidative activity in the cells have not been elucidated yet. We first examined to clarify the mechanism involving cancer cell death using one of the intracellular redox-regulatory systems, Nrf2/ARE (nuclear erythroid 2-related factor 2/ antioxidant response element) pathway. The results showed that the molecular hydrogen does not exert its antioxidative effect through common Nrf2 activation pathway.
The molecular hydrogen under the condition of dissolved hydrogen and Pt Nps coexistence, it is adsorbed to Pt Nps which triggers dissociation or weakening of the covalent bonds resulting in the acquisition of its reactivity similar to hydrogen radical we called active hydrogen in the aqueous environment. We found that such active hydrogen induces a strong cancer cell death while no such effect was detected in normal PBMC cells. We are speculating that this active hydrogen in ERW is the potential substance conferring antitumor effect. Our current effort is to find an alternative possibility for new anticancer therapy based on the present findings.
References 1. T. Omasa, K. Nishijima, Research for Cell Biology. 233: 652 (2014).

2. Takeki Hamasaki, Kiichiro Teruya, Shigeru Kabayama, What is functional water? Its recent findings, AFELiSA (International Symposium on Agricultural, Food, Environmental and Life Sciences in Asia) 2015, 2015.11, In the field of food science and technology, water is an important ingredient influencing taste, rheology and preservation of foods. Research on functional foods is currently popular; however, it is not yet well understood that drinking water also has physiological functions, and that there are some health-beneficial effects.
Many kinds of drinking waters said to be beneficial for health are commercialized in Japan. Those commercialized waters were often sold after activated by various methods including electrolysis, treatment with a magnetic field, light irradiation, ultrasonication, bubbling with gases, strong water flow and collision, and treatment with some types of minerals or rocks. However, most of such waters also introduced misunderstandings mainly due to lack of solid scientific evidences. Therefore, the functional water association of Japan was founded in 2002 for the purpose of defining functional water and verifying their efficacy and effectiveness by means of the scientific methods. Functional water is defined by the association as the water which is scientifically verified its production methods and functions selected from waters that have been produced by artificial methods capable of reproducibly giving rise to useful functions. At present, several functional waters are being examined and approved as alkaline ion water, acidic water, ozone water, supercritical water. Verification is in progress for fine bubble water, ocean deep water, hydrogen dissolved water, while magnetic treated water, radiation treated water, ultrasonic treated water and ceramic treated water seem not to have enough scientific proofs at this moment.
 Among functional waters, electrolyzed water has been investigated extensively. Alkali ion water, called electrochemically reduced water is produced near a cathode and electrochemically oxidized water is produced near an anode. Oxidized water is also termed electrolyzed acidic water and is functional water exhibiting a sterilizing action, mainly due to hypochlorous acid, chlorine gas, and ozone. electrochemically reduced water are expected to have preventive and positive effects on oxidative stress-related diseases such as diabetes, cancer, arteriosclerosis, neurodegenerative diseases, and side effects of hemodialysis. It has been suggested that the active agents in reduced water are hydrogen (atoms and molecules), mineral nanoparticles, and mineral nanoparticle hydrides.
In the presentation, additional efficacies of functional water based on the recent findings will be introduced and discuss about future possibilities of these waters..
3. H-Transfer Reaction by Pt nanoparticles.
  • Analysis of bioactivites by reduced water using animal cultured cells