| 摘要: | 多巴(3,4-dihydroxyphenyl-alanine, DOPA)是人體中樞神經傳導介質、腎上腺素和麥拉寧色素的前驅物質，可用來治療巴金森氏症。目前有關DOPA與人體相關的生物活性探討，所知仍有限，本論文的研究目的主要是探討DOPA之生物活性。
本論文分別利用紫外線B照射之測定、細胞存活率分析、超氧化歧酶分析、自由基測定等方法探討DOPA與紫外線B及自由基之關係。
研究結果顯示DOPA可清除1,1-diphenyl-2-picryl hydrazyl (DPPH) 、nitric oxide (NO)、2,2-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS)、liposome自由基，且可避免紫外線B對3T3纖維母細胞的傷害。25uM的DOPA 其DPPH自由基之清除率有80%以上與tocopherol相近;DOPA和quercetin在25uM濃度下，NO自由基的清除率皆有60%左右;在清除ABTS自由基活性方面，DOPA與ascorbic acid皆是不錯的抗氧化物;在liposome系統的測試結果顯示DOPA和tocopherol在相同25ppm濃度下，DOPA清除liposome自由基有80%以上的清除率，而tocopherol只有20%左右的清除率。另本研究亦發現DOPA可以保護紫外線B照射對3T3纖維母細胞所引發的死亡及避免細胞內超氧化歧酶的增加。
本論文的結果顯示DOPA在防曬、清除自由基、抗氧化、抗老化、等領域有其研究及臨床應用上的潛力價值。
3,4-dihydroxyphenyl-alanine (DOPA) is one of central nervous system transmission media, a precursor of the adrenalin or the melanin and may treat Parkinson、s disease in human. At present, the knowledge regarding DOPA and its biological activity is still limited. The objective of this study was to investigate the biological activity of DOPA .
The study was to investigate the protection of DOPA on ultraviolet ray B (UV-B) illumination, the relation of DOPA and free radical by using the UV-B illumination, the cell survival percentage analysis, superoxide dismutases (SOD) assay, the free radical assay.
Results of the study showed that DOPA has 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide (NO), 2,2-azino-bis(3-ethylbenz-
thiazoline-6-sulfonic acid) (ABTS), and liposome free radical scavenging activities, and also protecting fibroblast from UV-B radiation. Data indicated that DOPA with concentration of 25uM was higher scavenging activity of DPPH than 80%, and is similar to that of tocopherol;DOPA (25uM) had the same NO free radical scavenging activity (60%) with quercetin (25uM);in the analysis of ABTS free radical scavenging activity, DOPA and ascorbic acid were good antioxidants;in the liposome system assay, results also demonstrated that DOPA showed stronger scavenging activity than tocopherol with same concentration. In the UV-B illumination, DOPA can protect 3T3 fibroblast from death and prevent the increasing of SOD .
The result of this study indicated DOPA in guards against exposes to the sun and to eliminate free radical, anti-oxidation, and anti-aging with further research and clinical practice potential value. |
