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Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review
BACKGROUND: Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutriti...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5525358/ https://www.ncbi.nlm.nih.gov/pubmed/28769992 http://dx.doi.org/10.1186/s12986-017-0197-z |
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author | Delimont, Nicole M. Rosenkranz, Sara K. Haub, Mark D. Lindshield, Brian L. |
author_facet | Delimont, Nicole M. Rosenkranz, Sara K. Haub, Mark D. Lindshield, Brian L. |
author_sort | Delimont, Nicole M. |
collection | PubMed |
description | BACKGROUND: Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. AIM: To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme iron bioavailability with tannin consumption in vivo. METHODS: Narrative systematic review and meta-analysis. Common themes in biochemical modeling and affinity studies were collated for summary and synthesis; data were extracted from in vivo experiments for meta-analysis. RESULTS: Thirty-two studies were included in analysis. Common themes that positively influenced tannin-PRP binding included specificity of tannin-PRP binding, PRP and tannin stereochemistry. Hydrolyzable tannins have different affinities than condensed tannins when binding to PRPs. In vivo, hepatic iron stores and non-heme iron absorption are not significantly affected by tannin consumption (d = −0.64-1.84; −2.7-0.13 respectively), and PRP expression may increase non-heme iron bioavailability with tannin consumption. CONCLUSIONS: In vitro modeling suggests that tannins favor PRP binding over iron chelation throughout digestion. Hydrolyzable tannins are not representative of tannin impact on non-heme iron bioavailability in food tannins because of their unique structural properties and PRP affinities. With tannin consumption, PRP production is increased, and may be an initial line of defense against tannin-non-heme iron chelation in vivo. More research is needed to compare competitive binding of tannin-PRP to tannin-non-heme iron complexes, and elucidate PRPs’ role in adaption to non-heme iron bioavailability in vivo. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12986-017-0197-z) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-5525358 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-55253582017-08-02 Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review Delimont, Nicole M. Rosenkranz, Sara K. Haub, Mark D. Lindshield, Brian L. Nutr Metab (Lond) Review BACKGROUND: Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. AIM: To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme iron bioavailability with tannin consumption in vivo. METHODS: Narrative systematic review and meta-analysis. Common themes in biochemical modeling and affinity studies were collated for summary and synthesis; data were extracted from in vivo experiments for meta-analysis. RESULTS: Thirty-two studies were included in analysis. Common themes that positively influenced tannin-PRP binding included specificity of tannin-PRP binding, PRP and tannin stereochemistry. Hydrolyzable tannins have different affinities than condensed tannins when binding to PRPs. In vivo, hepatic iron stores and non-heme iron absorption are not significantly affected by tannin consumption (d = −0.64-1.84; −2.7-0.13 respectively), and PRP expression may increase non-heme iron bioavailability with tannin consumption. CONCLUSIONS: In vitro modeling suggests that tannins favor PRP binding over iron chelation throughout digestion. Hydrolyzable tannins are not representative of tannin impact on non-heme iron bioavailability in food tannins because of their unique structural properties and PRP affinities. With tannin consumption, PRP production is increased, and may be an initial line of defense against tannin-non-heme iron chelation in vivo. More research is needed to compare competitive binding of tannin-PRP to tannin-non-heme iron complexes, and elucidate PRPs’ role in adaption to non-heme iron bioavailability in vivo. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12986-017-0197-z) contains supplementary material, which is available to authorized users. BioMed Central 2017-07-24 /pmc/articles/PMC5525358/ /pubmed/28769992 http://dx.doi.org/10.1186/s12986-017-0197-z Text en © The Author(s). 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Review Delimont, Nicole M. Rosenkranz, Sara K. Haub, Mark D. Lindshield, Brian L. Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
title | Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
title_full | Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
title_fullStr | Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
title_full_unstemmed | Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
title_short | Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
title_sort | salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review |
topic | Review |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5525358/ https://www.ncbi.nlm.nih.gov/pubmed/28769992 http://dx.doi.org/10.1186/s12986-017-0197-z |
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