14E-38 |
Synergistic effect of antioxidant phenolic acids on human phenolsulphotransferase |
C. T. YEH, Department of Food Science, National Chung-Hsing University, 250 Kuokuang Road, Taichung, 40227, Taiwan and G. C. Yen, Dept. of Food Science, National Hsing Univ., 250 Kuokuang Rd., Taichung, 40227, Taiwan. Justification: Sulfate conjugation by phenolsulfotransferase (PST) is an important process in the detoxification of xenobiotics and endogenous compounds. There are two forms of PST for the sulfation of small phenols (PST-P) and monoamines (PST-M). Our previous studies revealed that p-hydroxybenzoic acid, gentistic acid, ferulic acid, gallic acid, and coumaric acid increased both the PST-P and PST-M activities. These phenolic acids also possessed antioxidant capacity in both the ORAC and TEAC assays. However, only limited knowledge is available for the synergistic action of these antioxidant phenolic acids on both forms of PST activities. Objectives: The purpose of this study was to investigate the synergistic effect of the combinations of phenolic acids on human PST activities. Methods: Human platelet homogenate was incubated with [35S]-labeled PAPS and the radioactivity was measured by liquid scintillation spectrometry. Protein content of platelet was estimated by the method of Bradford with BSA as a standard. The combination of p-hydroxybenzoic acid, gentistic acid, ferulic acid, gallic acid, and coumaric acid on both forms of PST activity were evaluated in a random order at concentrations of 2.5, 5.0 and 7.5£gM. Results: When p-hydroxybenzoic acid was combined with other phenolic acids, a synergistic effect on the promotion of PST-P activity was obtained. The PST-M activity was also significantly increased by gentistic acid when combined with other phenolic acids. A potential synergistic effect on PST-P activity was also found on the combinations of p-hydroxybenzoic, m- coumaric acid and gallic acid as well as p-hydroxybenzoic, m- coumaric acid and o- coumaric acid. Thus, the activity of both forms of PST could be promoted by the two or three combinations of these phenolic acids. Signification: These results provided more understanding in the effect of phenolic acids on human PST activities as well as information on the intake of antioxidant phenolic acids for human health.
Session 14E, Nutraceuticals & Functional Foods: General I
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