Antioxidative Function of Plant Polyphenols in Mammalian Cells
| Project/Area Number |
06660162
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
食品科学・栄養科学
|
|---|
| Research Institution | University of Shizuoka |
|---|
Principal Investigator |
NAKAYAMA Tsutomu University of Shizuoka, School of Food and Nutritional Sciences, Associate Professor, 食品栄養科学部, 助教授 (50150199)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HASHIMOTO Kei University of Shizuoka, School of Food and Nutritional Sciences, Research Associ, 食品栄養科学部, 助手 (10237935)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Project Status |
Completed (Fiscal Year 1995)
|
| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥1,800,000 (Direct Cost: ¥1,800,000)
|
|---|
| Keywords | plant polyphenols / active oxygens / hydrogen peroxide / cultured cells / antioxidant / curcumin / caffeic acid / SOD |
|---|
| Research Abstract |
(1) Cytotoxicity and DNA single-strand breaks caused by H_2O_2 were assessed by a colony formation assay and a DNA precipitation assay, respectively, with Chinese hamster V79 cells. In both assays, caffeic acid ethyl ester showed protective effects. The structure-activity relationship showed that the omicron-dihydroxy structure of caffeic acid ethyl ester was essential for the protective effects.
(2) We assessed inhibitory effects of curcumin and its chemically modified homologues against H_2O_2-induced cytotoxicity toward Chinese hamster long fibroblasts V79 cells with a colony formation assay. Among 4 curcuminoids, dihydroxycurcumin and dihydroxytetrahydrocurcumin suppressed H_2O_2-induced cytotoxicity. On the contrary, neither curcumin nor tetrahydrocurcumin showed any suppressive effects. These results support out empirical rule that omicron-dihydroxy (catechol) moiety is essential for the inhibitory effects.
(3) We established a simple method to quantify hydrogen peroxide (H_2O_2) generated during the aerobic heating process of (+) -catechin solution Using this method, we found that nonenzymatic H_2O_2 formation from catechin depended on pH,temperature, incubation time, and the presence of O_2 in the solution. The formation of oxidezed products of (+) -catechin, which was estimatied by measuring the absorbance of the solution at 430 nm, also depended on these factors. The H_2O_2 formation was inhibited by various kinds of superoxide dismutase (SOD) with almost the same dose dependency. Although the oxidation of (+) -catechin was enhanced by superoxide (O_2-), neither catalase nor H_2O_2 had any effects on the oxidation. These results suggest that O_2-, rather than H_2O_2, participated in the autoxidation of (+) -catechin, which was coupled with the H_2O_2 formation.
|
Report
(3 results)
Research Products
(6 results)
