Antioxidant role of astaxanthin in the green alga Haematococcus pluvialis
Antioxidant role of astaxanthin in the green alga Haematococcus pluvialis
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DOI：
10.1007/s002530051061
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发表时间：
1997-09-01
影响因子：
5
通讯作者：
Tsuji, Y
中科院分区：
文献类型：
--
作者：
Kobayashi, M;Kakizono, T;Tsuji, Y
雨生红球藻是一种绿色单细胞藻类，对环境氧化应激有两种抗氧化机制：营养细胞中的抗氧化酶和胞囊细胞中的抗氧化酮类胡萝卜素虾青素。我们将一种能产生超氧阴离子自由基(O-2(-))的试剂甲基紫精添加到雨生红藻成熟和未成熟的包囊中。成熟包囊对甲基紫精的耐受性高于未成熟包囊。成熟的(富含虾青素的)胞囊在通透性细胞中对O-2(-)有很高的抗氧化活性，但在无虾青素的细胞提取物中没有，而未成熟的(贫虾青素的)胞囊对O-2(-)的抗氧化活性很低。结果表明，胞囊细胞中积累的虾青素对过度氧化应激具有抗氧化剂的作用。在渗透细胞和营养细胞的细胞提取物中对O-2(-)具有相同水平的抗氧化活性，这表明存在抗氧化酶(超氧化物歧化酶)。
The green unicellular alga, Haematococcus pluvialis has two antioxidative mechanisms against environmental oxidative stress: antioxidative enzymes in vegetative cells and the antioxidative ketocarotenoid, astaxanthin, in cyst cells. We added a reagent that generates superoxide anion radicals (O-2(-)), methyl viologen, to mature and immature cysts of H. pluvialis. Tolerance to methyl viologen was higher in mature than in immature cysts. Mature (astaxanthin-rich) cysts showed high antioxidant activity against O-2(-) in permeabilized cells, but not in astaxanthin-free cell extracts, while immature (astaxanthin-poor) cysts had very low antioxidant activities against O-2(-) in both. The results suggested that astaxanthin accumulated in the cyst cells functions as an antioxidant against excessive oxidative stress. The same levels of antioxidant activities against O-2(-) in both permeabilized cells and cell extracts from vegetative cells suggested the presence of antioxidative enzymes (superoxide dismutase).