Measurement of Scavenging Ability Against Various Reactive Oxygen SpeciesUsing Electron Spin Resonance (ESR) Method

Measurement of the Scavenging Ability of Water-Soluble Silicon “umo®”

Against Various Reactive Oxygen Species

January 2014 (Heisei 26)

Supervisor: 

Taiichi Maeda

Person in Charge of Measurement: 

Professor Lee Chang-Il, Graduate School, Kanagawa Dental University

Measurement Staff: 

Fumihiko Yoshino, Graduate School, Kanagawa Dental University

1. Purpose of Measurement

The purpose is to measure the scavenging ability of water-soluble silicon “umo®” against various reactive oxygen species using the electron spin resonance (ESR) method.

2. Target Reactive Oxygen Species

1. Superoxide

2. Hydroxyl Radical

3. Singlet Oxygen

3. Sample

1. Umo® concentrated solution

3.1 Sample PreparationTo measure concentration-dependent scavenging activity, the sample was diluted with ultrapure water to prepare the following stock solutions:

1. Original sample solution

2. 10× dilution

3. 100× dilution

4. Reactive Oxygen Spin Trap Reagents [Trapping Agents]

1. Superoxide / Hydroxyl Radical Trap: CYPMPO: 5-(2,2-dimethyl-1,3-propoxycyclophosphoryl)-5-methyl-1-pyrroline-oxide, Radical Research

2. Singlet Oxygen Trap: 4-OH-TEMP: 2,2,6,6-tetramethyl-4-piperidinol, Aldrich

5. Other Experimental Reagents

1. PBS: Phosphate Buffer Saline pH 7.2, GIBCO/Invitrogen

2. Rose Bengal, Wako Pure Chemical Industries

3. Hydrogen Peroxide, Wako Pure Chemical Industries

4. Titanium Dioxide (Anatase Type), Wako Pure Chemical Industries

6. ESR Measurement Conditions

1. Evaluation of Antioxidant Activity Against Hydroxyl Radicals Using Photolysis of Hydrogen Peroxide

• PBS 140 μl

• CYPMPO 20 μl (final concentration 1.0 mM)

• Sample 20 μl (final concentration: 10× dilution of stock solution)

• H₂O₂ 20 μl (final concentration 100 mM)

• ESR measurement after UV irradiation (100 mW, 10 sec)

2. Evaluation of Antioxidant Activity Against Superoxide Anion Radical Using Titanium Dioxide Photocatalysis

• PBS 120 μl

• TiO₂ 20 μl (final concentration 0.30 wt%)

• CYPMPO 20 μl (final concentration 5.0 mM)

• Sample 20 μl (final concentration: 10× dilution of stock solution)

• H₂O₂ 20 μl (final concentration 3.0%)

• ESR measurement after UV irradiation (50 mW, 1.0 min)

3. Evaluation of Antioxidant Activity Against Singlet Oxygen Using Dye-Sensitized Reaction

• PBS 700 μl

• Rose Bengal 100 μl (final concentration 50 μM)

• 4-OH-TEMP 100 μl (final concentration 100 mM)

• Sample 100 μl (final concentration: 10× dilution of stock solution)

• Light irradiation: 18,000 lux, 1 min

• ESR measurement 1 min after light irradiation

○ Scavenging Effect Against Superoxide

Scavenging rate was calculated from the signal intensity enclosed in the box.

○ Scavenging Effect Against Hydroxyl Radical

Scavenging rate was calculated from the signal intensity enclosed in the box.

○ Scavenging Effect Against Singlet Oxygen

Scavenging rate was calculated from the signal intensity enclosed in the box.

○ Investigation of the Possibility of Photocatalytic Activity of Silicon Itself

1. Purpose of MeasurementTo investigate any photocatalytic activity of water-soluble silicon “umo®” using the ESR method.

2. Target Reactive Oxygen Species

1. Hydroxyl Radical

3. Sample

1. Umo® concentrated solution

4. Reactive Oxygen Spin Trap Reagents [Trapping Agents]

1. Hydroxyl Radical Trap: CYPMPO: 5-(2,2-dimethyl-1,3-propoxycyclophosphoryl)-5-methyl-1-pyrroline-oxide, Radical Research

5. Other Experimental Reagents

1. PBS: Phosphate Buffer Saline pH 7.2, GIBCO/Invitrogen

6. ESR Measurement ConditionsEvaluation of Antioxidant Activity Against Hydroxyl Radicals Using Photolysis of Hydrogen Peroxide

• PBS 160 μl

• CYPMPO 20 μl (final concentration 1.0 mM)

• Umo® 20 μl (final concentration: 10× dilution of stock solution)

• ESR measurement after UV irradiation (100 mW, 10 sec)

7. Results

No photocatalytic activity was observed for the water-soluble silicon “umo®” itself.

Note: This paper is translated from the following URL. The content is provided for reference on the scientific research of the raw material only. Whether APA raw materials are used or not, we hope this research will help increase understanding and awareness of body minerals.

www.apa-corp.jp

各種活性酸素種に対する消去能測定 - 株式会社APAコーポレーション

電子スピン共鳴 (ESR) 法を用いた 各種活性酸素種に対する水溶性珪素「umo®」の消去能測定 平成26年1