Development of pH-Responsive Antioxidants as Radioprotectors for Normal Tissues

2016 Fiscal Year Final Research Report

• Project/Area Number: 26460056
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical pharmacy
• Research Institution: National Institutes for Quantum and Radiological Science and Technology
• Principal Investigator: NAKANISHI Ikuo 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 放射線障害治療研究部, 主幹研究員 (70356137)
• Research Collaborator: WAKI Tsukasa
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 放射線防護剤 / 抗酸化物質 / 放射線がん治療 / 活性酸素種 / ラジカル / pH / 有機化学 / レドックス化学

Outline of Final Research Achievements

The pH of normal tissues is known to be higher than that of tumors. It is also known that radiation damages are mainly caused by reactive oxygen species (ROS) generated via ionization and/or excitation of water molecules by ionizing radiation. Thus, pH responsive antioxidants that can selectively scavenge ROS in normal tissues were investigated to protect normal tissues from radiation damage during cancer radiotherapy. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radial is frequently used as a reactivity model of ROS to evaluate activity of antioxidants. However, the insolubility of DPPH radical in water has precluded from its use in aqueous systems. In this study, DPPH radical was successfully solibilized in water using a cyclodextrin. This enables us to investigate the effect of pH on the radical-scavenging rates of water-soluble antioxidants in order to develop radioprotectors, which can selectively protect normal tissues from the radiation damages during radiotherapy.

Free Research Field

レドックス化学