Food Chemistry and Toxicology, Molecular Nutrition, University of Kaiserslautern, Erwin-Schroedinger-Strasse 52, Kaiserslautern, Germany.
Mol Nutr Food Res. 2012 Oct;56(10):1488-500. doi: 10.1002/mnfr.201200222. Epub 2012 Sep 4.
Until now, the question of how the ingested doses of chlorogenic acids (CGA) from coffee influence their absorption and metabolism remains unresolved. To assess absorption in the small intestine, we performed a dose-response study with a randomized, double-blinded, crossover design with ileostomist subjects.
After a polyphenol-free diet, the volunteers consumed, on three separate occasions, coffee with different total CGA contents (high 4525 μmol; medium 2219 μmol; low 1053 μmol). CGA concentrations in plasma, ileal effluent, and urine were subsequently determined by HPLC-DAD-ESI-MS and -ESI-MS/MS. The results show that the consumption of higher CGA concentrations leads to a faster ileal excretion. This corresponds to a renal excretion of 8.0 ± 4.9% (high), 12.1 ± 6.7% (medium), and 14.6 ± 6.8% (low) of total CGA and metabolites. Glucuronidation of CGA became slightly greater with increasing dose. After enzyme treatment, the area under the curve (AUC)(0-8h) for CGA metabolites in plasma was 4412 ± 751 nM × h(0-8) (-1) (high), 2394 ± 637 nM × h(0-8) (-1) (medium), 1782 ± 731 nM × h(0-8) (-1) (low), respectively. Additionally, we were able to identify new metabolites of CGA in urine and ileal fluid.
We conclude that the consumption of high CGA concentrations via coffee might influence the gastrointestinal transit time and consequently affect CGA absorption and metabolism.
到目前为止，关于摄入的咖啡中原生儿茶素酸（CGA）剂量如何影响其吸收和代谢的问题仍未解决。为了评估在小肠中的吸收情况，我们采用随机、双盲、交叉设计，让回肠造口术受检者进行了剂量反应研究。
在进行多酚含量无差别的饮食后，志愿者分别在三种不同情况下饮用了含有不同总量 CGA 的咖啡（高剂量 4525 μmol；中剂量 2219 μmol；低剂量 1053 μmol）。随后通过 HPLC-DAD-ESI-MS 和 ESI-MS/MS 来测定血浆、回肠流出物和尿液中的 CGA 浓度。结果表明，较高 CGA 浓度的摄入会导致更快的回肠排泄。这相当于肾脏排泄的总 CGA 和代谢物的 8.0 ± 4.9%（高剂量）、12.1 ± 6.7%（中剂量）和 14.6 ± 6.8%（低剂量）。CGA 的葡糖醛酸化随着剂量的增加而略有增加。经过酶处理后，血浆中 CGA 代谢物的 AUC(0-8h) 为 4412 ± 751 nM×h(0-8) (-1)（高剂量）、2394 ± 637 nM×h(0-8) (-1)（中剂量）、1782 ± 731 nM×h(0-8) (-1)（低剂量）。此外，我们还能够在尿液和回肠液中鉴定出 CGA 的新代谢物。
我们的结论是，通过咖啡摄入高浓度的 CGA 可能会影响胃肠道的转运时间，从而影响 CGA 的吸收和代谢。
