@article{VolppFerianecJežovičovaetal.2020,
  author    = {Volpp, Linda and Ferianec, Vladim{\´i}r and Ježovičov{\´a}, Miriam and Ďuračkov{\´a}, Zdeňka and Scherf-Clavel, Oliver and H{\"o}gger, Petra},
  title     = {Constituents and Metabolites of a French Oak Wood Extract (Robuvit®) in Serum and Blood Cell Samples of Women Undergoing Hysterectomy},
  series = {Frontiers in Pharmacology},
  volume    = {11},
  journal   = {Frontiers in Pharmacology},
  number    = {74},
  issn      = {1663-9812},
  doi       = {10.3389/fphar.2020.00074},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200105},
  year      = {2020},
  abstract  = {Ellagitannins are signature constituents of oak wood and their consumption has been associated with various health benefits. In vivo, they undergo metabolic degradation including gut microbial metabolism yielding urolithins. Only limited data is available about compounds being present in blood after intake of an extract from French oak wood, Robuvit®. In the course of a randomized, double-blind, controlled clinical investigation, 66 patients undergoing hysterectomy received placebo or 300 mg Robuvit® per day before and over 8 weeks after surgery. Serum and blood cell samples were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The number of urolithin producers and the urolithin levels increased after intake of Robuvit®. In serum samples, the median concentration of urolithin A was 14.0 ng/ml [interquartile range (IQR) 57.4] after 8 weeks. Urolithin B was determined at 22.3 ng/ml (IQR 12.6), urolithin C at 2.66 ng/ml (IQR 2.08). In blood cells, lower concentrations and only urolithins A and B were detected. A statistically significant association of lower post-surgical pain scores with metabotype A was detected (p < 0.05). To conclude, supplementation with French oak wood extract raised urolithin generation in patients and suggested health advantages for urolithin-producers.},
  language  = {en}
}
@article{MuelekSeefriedGenestetal.2017,
  author    = {M{\"u}lek, Melanie and Seefried, Lothar and Genest, Franca and H{\"o}gger, Petra},
  title     = {Distribution of constituents and metabolites of maritime pine bark extract (Pycnogenol\(^{®}\)) into serum, blood cells, and synovial fluid of patients with severe osteoarthritis: a randomized controlled trial},
  series = {Nutrients},
  volume    = {9},
  journal   = {Nutrients},
  number    = {5},
  doi       = {10.3390/nu9050443},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159862},
  pages     = {443},
  year      = {2017},
  abstract  = {The present randomized controlled study aimed to investigate the in vivo distribution of constituents or metabolites of the standardized maritime pine bark extract Pycnogenol\(^{®}\). Thirty-three patients with severe osteoarthritis scheduled for a knee arthroplasty were randomized to receive either 200 mg per day Pycnogenol\(^{®}\) (P+) or no treatment (Co) over three weeks before surgery. Serum, blood cells, and synovial fluid samples were analyzed using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization (LC-ESI/MS/MS). Considerable interindividual differences were observed indicating pronounced variability of the polyphenol pharmacokinetics. Notably, the highest polyphenol concentrations were not detected in serum. Catechin and taxifolin primarily resided within the blood cells while the microbial catechin metabolite δ-(3,4-dihydroxy-phenyl)-γ-valerolactone, ferulic, and caffeic acid were mainly present in synovial fluid samples. Taxifolin was detected in serum and synovial fluid exclusively in the P+ group. Likewise, no ferulic acid was found in serum samples of the Co group. Calculating ratios of analyte distribution in individual patients revealed a simultaneous presence of some polyphenols in serum, blood cells, and/or synovial fluid only in the P+ group. This is the first evidence that polyphenols distribute into the synovial fluid of patients with osteoarthritis which supports rationalizing the results of clinical efficacy studies.},
  language  = {en}
}