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Potent radical-scavenging activities of thiamin and thiamin diphosphate.

Okai Y, Higashi-Okai K, F Sato E, Konaka R, Inoue M - J Clin Biochem Nutr (2007)

Bottom Line: Various radical-scavenging activities of thiamin and thiamin diphosphate (TDP) were found in some in vitro experiments.Thiamin and TDP caused considerable suppressive effects on superoxide generation in hypoxanthine and xanthine oxidase system which was measured by a sensitive chemiluminescence method using 2-methyl-6-[p-methylphenyl]-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA), and their 50% inhibition (IC(50)) values were estimated to be 158 and 56 microM, respectively.These results strongly suggest a possibility that thiamin and TDP play as radical scavengers in cell-free and cellular systems.

View Article: PubMed Central - PubMed

Affiliation: Department of Human Life Science, Osaka Kun-Ei Women’s College, Sets city, Osaka 566-8501, Japan.

ABSTRACT
Various radical-scavenging activities of thiamin and thiamin diphosphate (TDP) were found in some in vitro experiments. Thiamin and TDP caused considerable suppressive effects on superoxide generation in hypoxanthine and xanthine oxidase system which was measured by a sensitive chemiluminescence method using 2-methyl-6-[p-methylphenyl]-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA), and their 50% inhibition (IC(50)) values were estimated to be 158 and 56 microM, respectively. They also showed the significant suppression against hydroperoxide generation derived from oxidized linoleic acid which was estimated by aluminum chloride method and their IC(50) values were calculated to be 260 and 46 microM. They further prevented the oxygen radical generation in opsonized zymosan-stimulated human blood neutrophils which was shown by chemiluminescence method using luminol, and their IC(50) values were calculated to be 169 and 38 microM. In contrast, they caused weak but significantly suppressive effects on the hydroxyl radical generation by Fenton reaction which was measured by electric spin resonance (ESR) method, their IC(50) values were calculated to be 8.45 and 1.46 mM respectively. These results strongly suggest a possibility that thiamin and TDP play as radical scavengers in cell-free and cellular systems.

No MeSH data available.


Related in: MedlinePlus

Effects of thiamin and TDP on oxygen radical generation in Opz-stimulated human blood nutrophils. The column and bar show the mean and SD of CHL intensities generated by oxygen radicals in triplicate assays. The statistical difference of the results between control and vitamin-treated experiments is analyzed by Student’s t test. The p value is expressed by each asterisk as follows. *p<0.05, **p<0.01, ***p<0.005, ****p<0.001, *****p<0.0001.
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Figure 4: Effects of thiamin and TDP on oxygen radical generation in Opz-stimulated human blood nutrophils. The column and bar show the mean and SD of CHL intensities generated by oxygen radicals in triplicate assays. The statistical difference of the results between control and vitamin-treated experiments is analyzed by Student’s t test. The p value is expressed by each asterisk as follows. *p<0.05, **p<0.01, ***p<0.005, ****p<0.001, *****p<0.0001.

Mentions: In addition to the cell-free experiments mentioned above, we analyzed the effects of thiamin and TDP on the oxygen radical generation in Opz-stimulated human blood neutrophils as a typical oxygen radical-producing cell system. As shown in Fig. 4, Opz considerably enhanced oxygen radical generation in human blood neutrophils which showed the strong luminol-dependent CHL generation. Another control solution PBS did not cause any significant effects on Opz-stimulated oxygen radical generation. When various concentrations (10 mM–20 µM) of thiamin and TDP were added to the cell mixture system before the exposure of Opz to neutrophils, Opz-induced oxygen radical generation was significantly suppressed in a dose-dependent fashion. Especially, at the highest concentration (10 mM), thiamin and TDP showed remarkable suppressive effects (93.7 and 99.2% inhibition). In this experimental system, TDP showed much stronger activity than thiamin, and IC50 values of thiamin and TDP were calculated to be 169 and 38 µM, respectively.


Potent radical-scavenging activities of thiamin and thiamin diphosphate.

Okai Y, Higashi-Okai K, F Sato E, Konaka R, Inoue M - J Clin Biochem Nutr (2007)

Effects of thiamin and TDP on oxygen radical generation in Opz-stimulated human blood nutrophils. The column and bar show the mean and SD of CHL intensities generated by oxygen radicals in triplicate assays. The statistical difference of the results between control and vitamin-treated experiments is analyzed by Student’s t test. The p value is expressed by each asterisk as follows. *p<0.05, **p<0.01, ***p<0.005, ****p<0.001, *****p<0.0001.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2291503&req=5

Figure 4: Effects of thiamin and TDP on oxygen radical generation in Opz-stimulated human blood nutrophils. The column and bar show the mean and SD of CHL intensities generated by oxygen radicals in triplicate assays. The statistical difference of the results between control and vitamin-treated experiments is analyzed by Student’s t test. The p value is expressed by each asterisk as follows. *p<0.05, **p<0.01, ***p<0.005, ****p<0.001, *****p<0.0001.
Mentions: In addition to the cell-free experiments mentioned above, we analyzed the effects of thiamin and TDP on the oxygen radical generation in Opz-stimulated human blood neutrophils as a typical oxygen radical-producing cell system. As shown in Fig. 4, Opz considerably enhanced oxygen radical generation in human blood neutrophils which showed the strong luminol-dependent CHL generation. Another control solution PBS did not cause any significant effects on Opz-stimulated oxygen radical generation. When various concentrations (10 mM–20 µM) of thiamin and TDP were added to the cell mixture system before the exposure of Opz to neutrophils, Opz-induced oxygen radical generation was significantly suppressed in a dose-dependent fashion. Especially, at the highest concentration (10 mM), thiamin and TDP showed remarkable suppressive effects (93.7 and 99.2% inhibition). In this experimental system, TDP showed much stronger activity than thiamin, and IC50 values of thiamin and TDP were calculated to be 169 and 38 µM, respectively.

Bottom Line: Various radical-scavenging activities of thiamin and thiamin diphosphate (TDP) were found in some in vitro experiments.Thiamin and TDP caused considerable suppressive effects on superoxide generation in hypoxanthine and xanthine oxidase system which was measured by a sensitive chemiluminescence method using 2-methyl-6-[p-methylphenyl]-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA), and their 50% inhibition (IC(50)) values were estimated to be 158 and 56 microM, respectively.These results strongly suggest a possibility that thiamin and TDP play as radical scavengers in cell-free and cellular systems.

View Article: PubMed Central - PubMed

Affiliation: Department of Human Life Science, Osaka Kun-Ei Women’s College, Sets city, Osaka 566-8501, Japan.

ABSTRACT
Various radical-scavenging activities of thiamin and thiamin diphosphate (TDP) were found in some in vitro experiments. Thiamin and TDP caused considerable suppressive effects on superoxide generation in hypoxanthine and xanthine oxidase system which was measured by a sensitive chemiluminescence method using 2-methyl-6-[p-methylphenyl]-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA), and their 50% inhibition (IC(50)) values were estimated to be 158 and 56 microM, respectively. They also showed the significant suppression against hydroperoxide generation derived from oxidized linoleic acid which was estimated by aluminum chloride method and their IC(50) values were calculated to be 260 and 46 microM. They further prevented the oxygen radical generation in opsonized zymosan-stimulated human blood neutrophils which was shown by chemiluminescence method using luminol, and their IC(50) values were calculated to be 169 and 38 microM. In contrast, they caused weak but significantly suppressive effects on the hydroxyl radical generation by Fenton reaction which was measured by electric spin resonance (ESR) method, their IC(50) values were calculated to be 8.45 and 1.46 mM respectively. These results strongly suggest a possibility that thiamin and TDP play as radical scavengers in cell-free and cellular systems.

No MeSH data available.


Related in: MedlinePlus