Volume 2 Supplement 1

Metabolism, Diet and Disease 2014: Cancer and metabolism

Open Access

Influence of polyphenol-rich apple pomace extract on oxidative damage to DNA in type 2 diabetes mellitus individuals

  • Annemarie Grindel1,
  • Elisabeth Müllner1,
  • Helmut Brath2,
  • Walther Jäger3,
  • Trine Henriksen4, 5,
  • Henrik Enghusen Poulsen5, 6,
  • Doris Marko7 and
  • Karl-Heinz Wagner1
Cancer & Metabolism20142(Suppl 1):P25

https://doi.org/10.1186/2049-3002-2-S1-P25

Published: 28 May 2014

Background

Diabetes mellitus type 2 (DM2) is associated with increased oxidative stress and oxidative damage to DNA. An appropriate intake of antioxidants via the diet can improve this disturbed oxidative status [1]. Apples are the most widely consumed fruits in Europe and represent a major source of antioxidants due to their high polyphenol content [2]. Apple pomace as a polyphenol-rich byproduct of apple juice production could serve as a cheap and reliable tool for a nutraceutical with antioxidative properties.

Materials and methods

To test the antioxidant potential of a pectin-depleted apple pomace extract (APE) in human subjects, a placebo-controlled, crossover, double-blind, pilot human intervention study was performed. Eighteen postmenopausal women with DM2 (age=69.7±6.7 y; BMI=33.9±4.5 kg/m2) were randomly allocated to receive either APE (440 mg per capsule containing about 100 mg total polyphenols, once daily) or placebo during two 4-week supplementation periods separated by a 4-week wash-out period. Before and after each supplementation period oxidative damage to DNA (Comet Assay) in peripheral blood mononuclear cells (PBMC) and whole blood, urinary excretion of 8-oxo-7hydro-2’-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), glycated hemoglobin (HbA1c), fasting blood glucose, insulin, C-peptide and anthropometric indices were measured. The bioavailability of the main APE polyphenol Phloridzin and its metabolite Phloretin were analyzed in plasma samples.

Results

In contrast to the placebo-supplementation, APE resulted in detectable plasma Phloridzin (12.7±40.7 ng/ml) and Phloretin (19.3±36.5 ng/ml) concentrations. The study population was characterized by HbA1c =5 4.9±6.3 mmol/mol, fasting blood glucose = 8.1±1.9 mmol/l, fasting insulin = 99.3±36.6 pmol/l and C-peptide = 1.3±0.4 nmol/l baseline levels. However, these DM2 biomarkers were not influenced by the supplementation with APE compared to placebo. No changes occurred in 8-oxoGuo and 8-oxodG. FPG-sensitive sites of whole blood decreased (P = 0.026) regarding apple pomace intervention of both diet periods. Neither DNA strand breaks nor H2O2-sensitivity of DNA altered following APE supplementation.

Conclusions

Oxidatively damaged purines decreased after APE intervention while other markers of oxidative damage to DNA in DM2 individuals did not change after short-term supplementation with polyphenol-rich APE.

Authors’ Affiliations

(1)
Department of Nutritional Sciences, University of Vienna
(2)
Diabetes Outpatient Clinic, Health Centre South
(3)
Department of Clinical Pharmacy and Diagnostics, University of Vienna
(4)
Laboratory of Clinical Pharmacology
(5)
Department of Clinical Pharmacology, Bispebjerg Hospital
(6)
Health Science Faculty, University of Copenhagen
(7)
Institute of Food Chemistry and Toxicology, University of Vienna

References

  1. Müllner E, Brath H, Pleifer S, Schiermayr C, Baierl A, Wallner M, Fastian T, Millner Y, Paller K, Henriksen T, Poulsen HE, Forster E, Wagner KH: Vegetables and PUFA-rich plant oil reduce DNA strand breaks in individuals with type 2 diabetes. Mol Nutr Food Res. 2013, 57: 328-338. 10.1002/mnfr.201200343.View ArticlePubMedGoogle Scholar
  2. Hyson DA: A comprehensive review of apples and apple components and their relationship to human health. Adv Nutr. 2011, 2: 408-420. 10.3945/an.111.000513.PubMed CentralView ArticlePubMedGoogle Scholar

Copyright

© Grindel et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 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.

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