First‐Pass Metabolism of Chlorophylls in Mice

Abstract

1 Scope

The dietary intake of chlorophylls is estimated to be ≈50 mg d–1. However, their first pass metabolism and systemic assimilation is not well characterized. 2 Methods and results

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 e6 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. 3 Conclusion

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.