Posted 03 February 2008 - 04:57 AM
Pine bark usually loses to grape seed in head to head tests, and grape seed has a more diverse composition.
J Soc Biol. 2007;201(2):189-98.
[Inhibition of advanced glycation by flavonoids. A nutritional implication for preventing diabetes complications?]
[Article in French]
Urios P, Grigorova-Borsos AM, Peyroux J, Sternberg M.
Département de Biochimie, Faculté de Médecine & Laboratoire de Pharmacologie, Faculté de Pharmacie, Université René Descartes, Paris, France. paul.urios@bch.aphp.fr
Advanced glycation of collagens contributes to development of micro- and macrovascular complications in diabetes. Since flavonoids are potent natural antioxidants, it was interesting to examine their effect on the formation of a cross-linking advanced glycation endproduct, pentosidine, in collagen incubated with glucose. Monomeric flavonoids (25 and 250 microM) markedly reduced pentosidine/hydroxyproline values in a concentration- and structure-dependent manner. Procyanidin oligomers from grape seed were more active than pine bark procyanidin oligomers. Oligomers are known to be cleaved into monomers in the gastric milieu and monomeric flavonoids to be absorbed and recovered at micromolar concentrations (with a long plasmatic half-life) in extracellular fluids, in contact with collagens. In conclusion, flavonoids are very potent inhibitors of pentosidine formation in collagens, active at micromolar concentrations; these concentrations might be achieved in plasma of diabetic patients after oral intake of flavonoids.
PMID: 17978753
Eur J Nutr. 2007 Apr;46(3):139-46.
Flavonoids inhibit the formation of the cross-linking AGE pentosidine in collagen incubated with glucose, according to their structure.
Urios P, Grigorova-Borsos AM, Sternberg M.
Equipe de recherche "Protéines modifiées, protéases et physiopathologie de l'endothélium vasculaire", Dépt. de Biochimie, Faculté de Médecine and Laboratoire de Pharmacologie, Faculté de Pharmacie, Université René Descartes, Paris, France.
BACKGROUND: Glycoxidation of collagens contributes to development of vascular complications in diabetes. AIM OF THE STUDY: Since flavonoids are potent antioxidants present in vegetal foods, it was interesting to examine their effect on the formation of a cross-linking advanced glycation endproduct, pentosidine, in collagens. METHODS: Collagen was incubated with glucose (250 mM), in the presence of different flavonoids. Pentosidine was measured by HPLC, hydroxyproline colorimetrically. RESULTS: Monomeric flavonoids (25 and 250 microM) markedly reduced pentosidine/hydroxyproline values in a concentration- and structure-dependent manner. In decreasing order of their specific inhibitory activity, they rank as follows: myricetin > or = quercetin > rutin > (+)catechin > kaempferol. Thus 3'-OH or 4-oxo + Delta(2-3) increase the inhibitory activity; conjugation by Rha-Glc on 3-OH decreases it. Procyanidin oligomers from grape seed were more active than pine bark procyanidin oligomers: this may be related to the galloyl residues present in grape seed oligomers only. Procyanidin oligomers are known to be cleaved into monomers in the gastric milieu and monomeric flavonoids to be absorbed and recovered at micromolar concentrations (with a long plasmatic half-life) in extracellular fluids, in contact with collagens. CONCLUSION: Flavonoids are very potent inhibitors of pentosidine formation in collagens. They are active at micromolar concentrations; these might be achieved in plasma of diabetic patients after oral intake of natural flavonoids.
PMID: 17356796
J Agric Food Chem. 2007 Jan 10;55(1):148-56.
Comparison of proanthocyanidins in commercial antioxidants: grape seed and pine bark extracts.
Weber HA, Hodges AE, Guthrie JR, O'Brien BM, Robaugh D, Clark AP, Harris RK, Algaier JW, Smith CS.
Midwest Research Institute, 425 Volker Boulevard, Kansas City, Missouri 64110, USA.
The major constituents in grape seed and pine bark extracts are proanthocyanidins. To evaluate material available to consumers, select lots were analyzed using high-performance liquid chromatography, gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), gel permeation chromatography (GPC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Atmospheric pressure chemical ionization (APCI) LC/MS was used to identify monomers, dimers, and trimers present. GC/MS analyses led to the identification of ethyl esters of hexadecanoic acid, linoleic acid, and oleic acid, as well as smaller phenolic and terpene components. The GPC molecular weight (MW) distribution indicated components ranging from approximately 162 to approximately 5500 MW (pine bark less than 1180 MW and grape seed approximately 1180 to approximately 5000 MW). MALDI-TOF MS analyses showed that pine bark did not contain oligomers with odd numbers of gallate units and grape seed contained oligomers with both odd and even numbers of gallate. Reflectron MALDI-TOF MS identified oligomers up to a pentamer and heptamer, and linear MALDI-TOF MS showed a mass range nearly double that of reflectron analyses.
PMID: 17199326
Int J Vitam Nutr Res. 2006 Jan;76(1):22-7.
In vivo antioxidant activity of procyanidin-rich extracts from grape seed and pine (Pinus maritima) bark in rats.
Busserolles J, Gueux E, Balasińska B, Piriou Y, Rock E, Rayssiguier Y, Mazur A.
Centre de Recherche en Nutrition Humaine d'Auvergne, Unité des Maladies Métaboliques et Micronutriments, INRA, Theix, Saint-Genès-Champanelle, France.
BACKGROUND: In vitro evidence exists for the potential antioxidant benefits of procyanidin-rich extracts, but in vivo studies are scarce. We have evaluated the effects of selected procyanidin-rich extracts on oxidative stress in rats in condition of prolonged consumption of these compounds and also after single administration i.e. in postprandial conditions. METHODS: Rats were fed for 8 weeks with diets supplemented with either a grape seed extract (GE), a pine bark extract (PE), or a high-degree polymerized pine bark extract (HPE). An additional study was performed in order to assess the postprandial effect of these extracts on plasma antioxidant capacity. The ferric-reducing antioxidant power (FRAP) and thiobarbituric acid-reactive substances (TBARS) were determined in plasma. For lipid peroxidation study of heart tissue, homogenates were prepared and TBARS were measured after lipid peroxidation induced by FeSO4-ascorbate. RESULTS: After 8 weeks of dietary treatment, total antioxidant capacity in plasma was significantly higher in the GE and PE groups as compared with the other two groups. Plasma TBARS concentrations and heart susceptibility to peroxidation were not significantly different between the groups. In the postprandial state, by comparing plasma antioxidant capacity 2 hours after ingestion of the different procyanidin-rich extracts (500 mg/kg body weight), we observed that FRAP values were higher in the procyanidin-rich extracts groups as compared with the control group. Moreover, plasma FRAP concentration was significantly higher in the GE group as compared with the other groups. CONCLUSION: The results of the present experiment constitute positive evidence for an in vivo antioxidant effect at the plasma level of procyanidin-containing plant extracts.
PMID: 16711653
J Food Prot. 2004 Jan;67(1):148-55.
Antimicrobial and antioxidant activities of natural extracts in vitro and in ground beef.
Ahn J, Grün IU, Mustapha A.
Department of Food Science, 256 William Stringer Wing, Eckles Hall, University of Missouri, Columbia, Missouri 65211, USA.
Inhibition of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes by grape seed extract (ActiVin) and pine bark extract (Pycnogenol) and the effect of these natural extracts on the oxidative stability of raw ground beef were studied. In an agar dilution test, the MICs of ActiVin and Pycnogenol were determined to be 4.0 mg/ml for 4.43 log CFU per plate of E. coli O157:H7 and 4.0 mg/ml for 4.38 log CFU per plate of L. monocytogenes. In an inhibition curve test, populations of E. coli O157:H7, Salmonella Typhimurium, and L. monocytogenes fell to below the detection limit (10 CFU/ml) after 16 h of incubation. The numbers of E. coli O157:H7, L. monocytogenes, and Salmonella Typhimurium declined by 1.08, 1.24, and 1.33 log CFU/g, respectively, in raw ground beef treated with 1% Pycnogenol after 9 days of refrigerated storage. ActiVin (1%) and oleoresin rosemary (1%) resulted in an approximately 1-log CFU/g reduction in the populations of all three pathogens after 9 days. The addition of 1% ActiVin and Pycnogenol contributed to the maintenance of an acidic pH of 5.80 and 5.58, respectively, in raw ground beef. Compared to the control, all treatments increased in L* (lightness), with the exception of ActiVin. ActiVin and oleoresin rosemary had the highest a* (redness) and b* (yellowness) values, respectively. ActiVin most effectively retarded lipid oxidation, followed by Pycnogenol. The results suggest that these natural extracts have potential to be used with other preservative methods to reduce pathogenic numbers, lipid oxidation, and color degradation in ground beef.
PMID: 14717365
Food Microbiol. 2007 Feb;24(1):7-14.
Erratum in: Food Microbiol. 2007 Jun;24(4):432.
Effects of plant extracts on microbial growth, color change, and lipid oxidation in cooked beef.
Ahn J, Grün IU, Mustapha A.
Division of Biomaterials Engineering, Kangwon National University, Chucheon, Gangwon 200-701, Republic of Korea [corrected]
The effects of butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT), grape seed extract (ActiVin), pine bark extract (Pycnogenol), and oleoresin rosemary (Herbalox) on microbial growth, color change, and lipid oxidation were investigated in cooked ground beef. When compared to the control, 1.0% ActiVin and Pycnogenol) effectively reduced the numbers of Escherichia coli O157:H7 and Salmonella Typhimurium, and retarded the growth of Listeria monocytogenes and Aeromonas hydrophila. Pycnogenol resulted in reductions of 1.7, 2.0, 0.8, and 0.4 log CFU/g, respectively, in numbers of E. coli O157:H7, L. monocytogenes, S. Typhimurium, and A. hydrophila, respectively, after 9 days of refrigerated storage. The color of cooked beef treated with ActiVin was less light (L*), more red (a*), and less yellow (b*) than those treated with BHA/BHT, Pycnogenol, and Herbalox. ActiVin and Pycnogenol effectively retained the redness in cooked beef during storage. The control showed significantly higher thiobarbituric acid-reactive substances (TBARS) and hexanal content over storage. BHA/BHT, ActiVin, Pycnogenol, and Herbalox retarded the formation of TBARS by 75%, 92%, 94%, and 92%, respectively, after 9 days, and significantly lowered the hexanal content throughout the storage period. Results of this work show that ActiVin and Pycnogenol are promising additives for maintaining the quality and safety of cooked beef.
PMID: 16943089
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