Tsukui Takayuki, Konno Kensuke, Hosokawa Masashi, Maeda Hayato, Sashima Tokutake, Miyashita Kazuo
Faculty of Fisheries Sciences and Creative Research Institute, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
J Agric Food Chem. 2007 Jun 27;55(13):5025-9. doi: 10.1021/jf070110q. Epub 2007 May 31.
This study examined the effect of dietary fucoxanthin or fucoxanthinol on the amount of docosahexaenoic acid (DHA) in the liver of KKAy mice, a model for obese/type II diabetes. In the first experiment, mice were fed diets containing crude fucoxanthin or glyceroglycolipid for 4 weeks. Results showed a significant increase in the level of DHA in mice fed 0.53% crude fucoxanthin, from 2.3% in control mice to 5.1% of fatty acid composition of total liver lipids. On the other hand, in mice fed crude glyceroglycolipid, the level of DHA as a proportion of total liver fatty acids remained unchanged. To clarify the enhancement of hepatic DHA, in the second experiment, KKAy mice were fed a diet containing purified fucoxanthin or its deacetylated derivative, fucoxanthinol. Results from a quantitative analysis using an internal standard showed that in mice fed 0.2% fucoxanthin, the amount of hepatic DHA was 2-fold higher than in control mice, whereas DHA levels in the small intestine remained unchanged. Furthermore, 0.2% fucoxanthinol led to 1.8- and 1.2-fold increases in the amount of hepatic DHA and arachidonic acid compared to control mice, respectively. These results indicate for the first time that dietary fucoxanthin and fucoxanthinol enhance the amount of DHA in the liver of KKAy mice.
本研究考察了膳食岩藻黄质或岩藻黄醇对肥胖/II型糖尿病模型KKAy小鼠肝脏中二十二碳六烯酸（DHA）含量的影响。在第一个实验中，给小鼠喂食含有粗岩藻黄质或甘油糖脂的饲料4周。结果显示，喂食0.53%粗岩藻黄质的小鼠肝脏中DHA水平显著升高，从对照小鼠肝脏总脂质脂肪酸组成中的2.3%升至5.1%。另一方面，喂食粗甘油糖脂的小鼠肝脏中，DHA占总脂肪酸的比例没有变化。为了阐明肝脏中DHA含量增加的原因，在第二个实验中，给KKAy小鼠喂食含有纯化岩藻黄质或其脱乙酰衍生物岩藻黄醇的饲料。使用内标进行定量分析的结果显示，喂食0.2%岩藻黄质的小鼠肝脏中DHA含量比对照小鼠高出2倍，而小肠中的DHA水平没有变化。此外，与对照小鼠相比，0.2%岩藻黄醇使肝脏中DHA和花生四烯酸的含量分别增加了1.8倍和1.2倍。这些结果首次表明，膳食岩藻黄质和岩藻黄醇可提高KKAy小鼠肝脏中DHA的含量。
