碩士 / 國立中興大學 / 食品暨應用生物科技學系所 / 98 / Fucoxanthin is the major carotenoid in brown sea algae and has been shown to exert antioxidant activity. However, Fucoxanthin is highly unstable and it may attack by nucleophile molecule to cause the pro-oxidative actions because of its unique chemical structure including 5, 6-monoepoxide. Thus, the purpose of this research was to determine whether fucoxanthin activates cellular antioxidant enzyme expression via up-regulation of Nrf2/ antioxidant-response element (ARE) mechanism through its pro-oxidative actions. We incubated mouse hepatic BNL CL.2 cells with fucoxanthin (0.5-20 μM) for 0-24 h. We found that fucoxanthin significantly increased cellular reactive oxygen species level for 6 h and that inclusion of α-d-tocopherol (30 μM) significantly attenuated the increase of ROS, indicating that fucoxanthin has pro-oxidative actions. In addition, fucoxanthin significantly increased phosphorylation of ERK and p38 and markedly increased the protein expression (2.5 fold) of nuclear Nrf2 after incubation for 12 h. Moreover, fucoxanthin significantly enhanced the binding activities between nuclear Nrf2 and ARE, increased protein expression of HO-1 and NQO1 after incubation for 12 h. The use of small interfering RNA inhibition of Nrf2 leads to decreased HO-1and NQO1 protein expression. Thus, the present study demonstrates that fucoxanthin can activate the MAPK signaling pathway and the Nrf2/ARE system to induce HO-1 and NQO1gene expression, possibly through its pro-oxidative actions.
| Identifer | oai:union.ndltd.org:TW/098NCHU5253021 |
| Date | January 2010 |
| Creators | Yu-Ting Chiu, 邱郁婷 |
| Contributors | Miao-Lin Hu, 胡淼琳 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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