Food Phytochemistry Department, Instituto de la Grasa (CSIC),, 41013, Sevilla, Spain.
College of Food Science, Southwest University, Chongqing, 400715, China.
Mol Nutr Food Res. 2018 Sep;62(17):e1800562. doi: 10.1002/mnfr.201800562. Epub 2018 Aug 6.
The dietary intake of chlorophylls is estimated to be ≈50 mg d . However, their first pass metabolism and systemic assimilation is not well characterized.
A group of 30 mice are fed a diet rich in chlorophylls, while 10 mice received a standard diet without chlorophylls (control group). Liver extracts are analyzed every 15 days by HPLC-ESI(+)/APCI(+)-hrTOF- MS/MS to measure the accretion of specific chlorophyll metabolites. The chlorophyll profile found in the livers of mice fed a chlorophyll-rich diet shows that the formation and/or absorption of pheophorbides, pyro-derivatives, and phytyl-chlorin e require the occurrence of a precise first-pass metabolism. In addition, the apical absorption of pheorphorbide a-rich micelles is significantly inhibited in Caucasian colon adenocarcinoma-2 cells pre-incubated with BLT1.
Pheophorbide a absorption is, at least partly, protein-mediated through SR-BI. This active absorption process could explain the specific accumulation of pheophorbide a in the livers of animals fed a chlorophyll-rich diet. A complementary mechanism could be the de-esterification of pheophytin a in the liver, yielding pheophorbide a and phytol, which can explain the origin of phytol in the liver. Hence, the results suggest two molecular mechanisms responsible for the accumulation of the health-promoting compounds pheophorbide and phytol.
据估计，叶绿素的饮食摄入量约为 50mg/d。然而，其首过代谢和全身吸收尚未得到很好的描述。
一组 30 只小鼠喂食富含叶绿素的饮食，而 10 只小鼠喂食不含叶绿素的标准饮食（对照组）。每隔 15 天用 HPLC-ESI(+)/APCI(+)-hrTOF-MS/MS 分析肝提取物，以测量特定叶绿素代谢物的积累。在喂食富含叶绿素饮食的小鼠肝脏中发现的叶绿素图谱表明，原卟啉 b、焦衍生物和植基叶绿素 e 的形成和/或吸收需要精确的首过代谢。此外，在用 BLT1 预先孵育的白人结肠腺癌-2 细胞中，富含原卟啉 b 的胶束的顶端吸收明显受到抑制。
原卟啉 b 的吸收至少部分是通过 SR-BI 介导的蛋白质吸收。这种主动吸收过程可以解释富含叶绿素的饮食喂养的动物肝脏中原卟啉 b 的特定积累。补充机制可能是在肝脏中进行脱植基化，生成原卟啉 b 和植醇，这可以解释肝脏中植醇的来源。因此，这些结果表明了两种分子机制负责积累具有健康促进作用的化合物原卟啉 b 和植醇。
