著者

Yusuke Makino Megumi Ueno Yoshimi Shoji Minako Nyui Ikuo Nakanishi Koji Fukui Ken-ichiro Matsumoto

出版者

SOCIETY FOR FREE RADICAL RESEARCH JAPAN

雑誌

Journal of Clinical Biochemistry and Nutrition (ISSN:09120009)

巻号頁・発行日

pp.21-83, (Released:2021-12-25)

参考文献数

9

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The quantitative measurement of free radicals in liquid using an X-band electron paramagnetic resonance (EPR) was systematized. Quantification of free radicals by EPR requires a standard sample that contains a known spin amount/concentration. When satisfactory reproducibility of the sample material, volume, shape, and positioning in the cavity for EPR measurements can be guaranteed, a sample tested and a standard can be directly compared and the process of quantification can be simplified. The purpose of this study was to simplify manual quantitative EPR measurement. A suitable sample volume for achieving a stable EPR intensity was estimated. The effects of different solvents on the EPR sensitivity were compared. The stability and reproducibility of the EPR intensity of standard nitroxyl radical solutions were compared among different types of sample tubes. When the sample tubes, sample volumes, and/or solvents were the same, the EPR intensity was reproduced with an error of 2% or less for μM samples. The quantified sample and the standard sample in the same solvent and the same volume drawn into the same sample tube was able to be directly compared. The standard sample for quantification should be measured just before or after every daily experiment.

著者

Kazuhiro Kato Masaki Nagane Naoyuki Aihara Junichi Kamiie Masakatsu Miyanabe Shinobu Hiraki Xiaolin Luo Ikuo Nakanishi Yoshimi Shoji Ken-ichiro Matsumoto Tadashi Yamashita

出版者

SOCIETY FOR FREE RADICAL RESEARCH JAPAN

雑誌

Journal of Clinical Biochemistry and Nutrition (ISSN:09120009)

巻号頁・発行日

pp.20-73, (Released:2021-01-16)

参考文献数

41

被引用文献数

3

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Polyphenols are abundant in vegetables and fruit. They have been shown to have various antitumor, antioxidant, and anti-inflammatory effects. Here, we extracted the lipid-soluble fraction of polyphenols from fermented sweet potato (Ipomoea batatas). These lipid-soluble polyphenols mainly contained caffeic acid derivatives with strong antioxidant ability, which we hypothesized to affect diseases for which oxidative stress is a factor, such as cancer. We therefore investigated the antitumor and chemo-sensitizing effects of lipid-soluble polyphenols on E0771 murine breast cancer cells. The lipid-soluble polyphenols accumulated in the cells’ cytoplasm due to its high lipophilicity, and reduced reactive oxygen species through its strong antioxidant activity. The lipid-soluble polyphenols also arrested the cell cycle at G0/G1 by suppressing Akt activity, and enhanced the cytotoxicity of anticancer agents. In this model, lipid-soluble polyphenols inhibited tumor growth and enhanced the efficacy of chemotherapy drugs. These results suggest the potential of lipid-soluble polyphenols as a functional food to support cancer therapy.