條條斑紫菜（Porphyra yezoensis）屬於紅藻類(Rhodophyta)，紅毛菜目(Bangiales)，紅毛菜科 (Bangiaceae)，紫菜屬(Porphyra)。外觀為紫紅色。條斑紫菜為海苔食品的主要原料之一。條斑紫菜營養價值豐富，被認為具有降低血中膽固醇，預防動脈硬化的作用。而生物活性胜肽被認為是特定的 蛋白質片段。它們可以藉由酵素水解釋放後，進而扮演各種生理功能。已有研究證實條斑紫菜活性胜肽具有抑制血管收縮素轉換酶能力。同時，也有研究指出條斑紫菜活性胜肽可以誘發乳癌細胞凋亡反應，其機轉是藉由調節insulin-like growth factor-I receptor。 我們的預備試驗也發現條斑紫菜活性胜肽具有自由基捕捉與抑制肝細胞之氧化傷害作用，惟此活性之作用機制與相關研究，迄今仍甚為缺乏。因此，本計畫分為二年期之研究，其內容為： (1) 以SVEC內皮細胞模式，測定條斑紫菜活性胜肽對血管收縮素誘發內皮細胞發炎反應之抑制效應，並探討條斑紫菜活性胜肽作用機制。 (2)以HepG2肝細胞模式，解析條斑紫菜活性胜肽對有機過氧化物誘發肝胞細氧化傷害之保護效應，並 探討條斑紫菜活性胜肽保護機制。 這項研究將進一步確定條斑紫菜活性胜肽保護作用的分子機制，是否藉由抑制NF-kB與活化 Nrf2等不同路徑。此外，本研究結果將可以確認條斑紫菜活性胜肽應用於減少心血管疾病與保護肝臟 的重要性。 Porphyra yezoensis （Bangiaceae, Rhodophyta）is a critical red alga and a source of different nutrients in diet. P. yezoensis can decrease cholesterol level in blood and exhibit a protective role against arteriosclerosis production. Bioactive peptides are considered specific protein fragments that are inactive within the sequence of the parent protein. After they are released by enzymatic hydrolysis, they may exert various physiological functions. Previous studies indicated that bioactive peptides from P. yezoensis can decrease the activety of angiotensin I- converting enzyme. The bioactive peptides from P. yezoensis also induce apoptosis by regulating insulin-like growth factor-I receptor in MCF-7 breast cancer cells. In addition, based on our previous experiments, the bioactive peptides from P. yezoensis scavenged free radicals and displayed protective effects against oxidative damage in hepatocytes induced by oxidants. However, these mechanisms of cellular protection remain unclear. In order to reveal these uncertainties, a two-year period project is designed. The purposes are: (1) to determine the inhibitory effects of bioactive peptides from P. yezoensis on AngII induced inflammatory damage in SVEC cells. (2) to explore the protective effects of bioactive peptides from P. yezoensis on t-BHP induced oxidative damage in HepG2 cells. The results obtained will help to understand molecular mechanisms of bioactive peptides from P. yezoensis on regulation of NF-kB and Nrf2 pathways. In addition, these will facilitate the applied values of bioactive peptides from P. yezoensis on cardiovascular and liver diseases complementary therapy.
