Lakshminarayana R, Raju M, Krishnakantha T P, Baskaran V
Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore 570 020, India.
Mol Cell Biochem. 2006 Jan;281(1-2):103-10. doi: 10.1007/s11010-006-1337-3.
The bioavailability of lutein solubilized in mixed micelles containing either phosphatidylcholine (PC) or lysophosphatidylcholine (lysoPC) was evaluated in male rats. Mixed micelles contained 2.5 mM monooleoylglycerol, 7.5 mM oleic acid, 12 mM sodium taurocholate and 200 microM lutein either with 3 mM PC or lysoPC. To study lutein bioavailability, single and repeated dose experiments were conducted. For single dose study, group of rats (n = 30/group) were fed single dose of lutein solubilized in lysoPC (LPC group), PC (PC group) and no phospholipids (NoPL group) in micellar form. Each group was further divided in to five sub-groups (n = 6/sub group) to measure lutein bioavailability over time up to 9 h. For repeated dose study, group of rats (n = 6/group) were fed daily for 10 days a dose of lutein in mixed micelles with NoPL, PC and LPC. A separate group (n = 6) not fed mixed micelles was considered as zero-time control. In both the experiments, mixed micelles (0.2 ml/rat) were fed to the rat by direct intubation to the stomach. Results of single dose studies showed that the mean lutein levels in the plasma and liver of the PC group was significantly lower (p < 0.05) than those of the other two groups. Moreover, the average lutein level in the plasma and liver was significantly (p < 0.05) different among the groups in the order LPC > NoPL > PC. But, repeated dose experiment followed the order LPC > PC > NoPL. The level of lutein excreted through urine and feces of PC group was significantly higher (p < 0.05) than those of the other two groups. Thus, the results indicate that the PC in the mixed micelles suppressed the intestinal uptake of lutein after single dose but not after repeated dose and that lysoPC enhanced the absorption. In both the experiments, plasma and liver level of lutein was higher in LPC compared with PC group. Results also suggest that the luminal hydrolysis of PC to lysoPC is necessary for intestinal uptake of lutein solubilized in mixed micelles.
在雄性大鼠中评估了溶解于含有磷脂酰胆碱（PC）或溶血磷脂酰胆碱（lysoPC）的混合胶束中的叶黄素的生物利用度。混合胶束含有2.5 mM单油酰甘油、7.5 mM油酸、12 mM牛磺胆酸钠和200 μM叶黄素，其中PC或lysoPC的含量为3 mM。为了研究叶黄素的生物利用度，进行了单次和重复给药实验。对于单次给药研究，将大鼠组（每组n = 30）分别喂食单次剂量的以胶束形式存在的溶解于lysoPC中的叶黄素（LPC组）、PC中的叶黄素（PC组）以及不含磷脂的叶黄素（NoPL组）。每组进一步分为五个亚组（每组n = 6），以测量长达9小时内不同时间点的叶黄素生物利用度。对于重复给药研究，将大鼠组（每组n = 6）每天喂食一次含有NoPL、PC和LPC的混合胶束中的叶黄素，持续10天。将一个未喂食混合胶束的单独组（n = 6）作为零时间对照。在这两个实验中，通过直接插管到胃中给大鼠喂食混合胶束（0.2 ml/只大鼠）。单次给药研究结果表明，PC组血浆和肝脏中的叶黄素平均水平显著低于其他两组（p < 0.05）。此外，血浆和肝脏中叶黄素的平均水平在各实验组之间存在显著差异（p < 0.05）,顺序为LPC > NoPL > PC。但是，重复给药实验的顺序为LPC > PC > NoPL。PC组通过尿液和粪便排泄的叶黄素水平显著高于其他两组（p < 0.05）。因此，结果表明，单次给药后混合胶束中的PC抑制了叶黄素的肠道吸收，但重复给药后则没有，并且lysoPC增强了吸收。在这两个实验中，LPC组血浆和肝脏中的叶黄素水平均高于PC组。结果还表明，PC在肠腔水解为lysoPC对于混合胶束中溶解的叶黄素的肠道吸收是必要的。
