| Effect of folate-binding protein on intestinal transport of folic acid and 5-methyltetrahydrofolate across Caco-2 cells. | |
| | |
MedLine Citation:
|
PMID: 15316828 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
BACKGROUND: Milk products are a potential matrix for fortification with synthetic folic acid or natural 5-methyltetrahydrofolate (5-CH3-H4folate) to enhance the daily folate intake. In milk, folate occurs bound to folate-binding proteins (FBP). Our previous studies with an in vitro gastrointestinal model showed that 70% of the initial FBP content of the milk product was retained in the duodenal lumen. While folic acid remained bound to FBP after gastric passage, 5-CH3-H4folate was mainly present as free folate in the duodenal lumen. AIM OF THE STUDY: To investigate the effect of FBP on the absorption of folic acid and 5-CH3-H4folate from the intestinal lumen. METHODS: The transport of [3H]-folic acid and [14C]-5-CH3-H4folate across enterocytes was studied in the presence or absence of bovine FBP using monolayers of Caco-2 cells grown on semi-permeable inserts in a two-compartment model. The apparent permeability coefficients (P(app)) of folic acid and 5-CH3-H4folate were determined and compared with the permeability of reference compounds for low (mannitol) and high (caffeine) permeability. RESULTS: The transport from the apical to the basolateral side of the Caco-2 cells was higher (P < 0.05) for folic acid (P(app) = 1.7*10(-6) cm/s) than for 5-CH3-H4folate (P(app) = 1.4*10(-6) cm/s) after 2 h incubation to 1 microM folic acid or 5-CH3-H4folate test solutions (pH 7). The permeability of folic acid and 5-CH3-H4folate across Caco-2 monolayers appeared to be higher (P < 0.05) than that of mannitol (P(app) = 0.5*10(-6) cm/s) but lower (P < 0.05) than that of caffeine (P(app) = 34*10(-6) cm/s). The addition of FBP to the medium led to a lower (P < 0.05) intestinal transport and cellular accumulation of folic acid and 5-CH3-H4folate. CONCLUSIONS: Compared to the reference compounds, folic acid and 5-CH3-H4folate showed a moderate permeability across Caco-2 cells, which indicates that folate absorption from the intestinal lumen is not likely to be complete. The intestinal transport of folic acid and 5-CH3-H4folate was found to be dependent on the extent of binding to FBP at the luminal side of the cells. |
| | |
Authors:
|
Miriam Verwei; Henk van den Berg; Robert Havenaar; John P Groten |
Related Documents
:
|
19389458 - Effect of processing on folic acid fortified baladi bread and its possible effect on th... 4527808 - Formation of 10-formylfolic acid, a potent inhibitor of dihydrofolate reductase, in rat... 15447898 - Determining bioavailability of food folates in a controlled intervention study. 5637348 - Pyruvate metabolism by aminopterin-inhibited aerobacter aerogenes. 6157328 - Effects of portacaval shunt and transposition on fatty acid and cholesterol biosynthesi... 10484008 - Sluggish small bowel motility is involved in determining increased biliary deoxycholic ... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2004-08-17 |
Journal Detail:
|
Title: European journal of nutrition Volume: 44 ISSN: 1436-6207 ISO Abbreviation: Eur J Nutr Publication Date: 2005 Jun |
Date Detail:
|
Created Date: 2005-06-03 Completed Date: 2005-10-18 Revised Date: 2006-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 100888704 Medline TA: Eur J Nutr Country: Germany |
Other Details:
|
Languages: eng Pagination: 242-9 Citation Subset: IM |
Affiliation:
|
Physiological Sciences Dept., TNO Nutrition and Food Research, 360, 3700 AJ, Zeist, The Netherlands. verwei@voeding.tno.nl |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Biological Transport
/
drug effects Caco-2 Cells Carrier Proteins / metabolism, pharmacology* Cell Culture Techniques Chromatography, Gel Folic Acid / metabolism* Humans Intestinal Absorption Intestine, Small / metabolism* Receptors, Cell Surface / metabolism Tetrahydrofolates / metabolism* Time Factors |
| Chemical | |
Reg. No./Substance:
|
0/Carrier Proteins; 0/Receptors, Cell Surface; 0/Tetrahydrofolates; 0/folate-binding protein; 134-35-0/5-methyltetrahydrofolate; 59-30-3/Folic Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Plant sterol ester-enriched milk and yoghurt effectively reduce serum cholesterol in modestly hyperc...
Next Document: Dietary patterns and the adenomacarcinoma sequence of colorectal cancer.