title: Extract from Rumex acetosa L. for prophylaxis of periodontitis: inhibition of bacterial in vitro adhesion and of gingipains of Porphyromonas gingivalis by epicatechin-3-O-(4β→8)-epicatechin-3-O-gallate (procyanidin-B2-Di-gallate).
abstract: BACKGROUND
  The aerial parts of Rumex acetosa L. have been used in traditional European medicine for inflammatory diseases of the mouth epithelial tissue. The following study aimed to investigate the influence of a proanthocyanidin-enriched extract from R. acetosa extract against the adhesion of Porphyromonas gingivalis (P. gingivalis), a pathogen strongly involved in chronic and aggressive periodontitis. A further goal was to define the bioactive lead structures responsible for a potential antiadhesive activity and to characterize the underlying molecular mechanisms of the antiadhesive effects.
  
  
  METHODS
  An extract of R. acetosa (RA1) with a defined mixture of flavan-3-ols, oligomeric proanthocyanidins and flavonoids, was used. Its impact on P. gingivalis adhesion to KB cells was studied by flow cytometry, confocal laser scanning microscopy and in situ adhesion assay using murine buccal tissue. RA1 and its compounds 1 to 15 were further investigated for additional effects on gingipain activity, hemagglutination and gene expression by RT-PCR.
  
  
  RESULTS
  RA1 (5 to 15 μg/mL) reduced P. gingivalis adhesion in a dose-dependent manner to about 90%. Galloylated proanthocyanidins were confirmed to be responsible for this antiadhesive effect with epicatechin-3-O-gallate-(4β,8)-epicatechin-3'-O-gallate (syn. procyanidin B2-di-gallate) being the lead compound. Ungalloylated flavan-3-ols and oligomeric proanthocyanidins were inactive. RA1 and the galloylated proanthocyanidins strongly interact with the bacterial virulence factor Arg-gingipain, while the corresponding Lys-gingipain was hardly influenced. RA1 inhibited also hemagglutination. In silico docking studies indicated that epicatechin-3-O-gallate-(4β,8)-epicatechin-3'-O-gallate interacts with the active side of Arg-gingipain and hemaglutinin from P. gingivalis; the galloylation of the molecule seems to be responsible for fixation of the ligand to the protein. In conclusion, the proanthocyanidin-enriched extract RA1 and its main active constituent procyanidin B2-di-gallate protect cells from P. gingivalis infection by inhibiting bacterial adhesion to the host cell. RA1 and procyanidin B2-di-gallate appear to be promising candidates for future cytoprotective preparations for oral mouth care products.
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Jana
authors: J
authors: Schmuch
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Sabine
authors: S
authors: Beckert
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Simone
authors: S
authors: Brandt
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Gesine
authors: G
authors: Löhr
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Fabian
authors: F
authors: Hermann
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Thomas J
authors: TJ
authors: Schmidt
authors: Heinrich-Heine-University, Department of Operative Dentistry, Periodontics and Endodontics, Düsseldorf, Germany.
authors: Thomas
authors: T
authors: Beikler
authors: University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Münster, Germany.
authors: Andreas
authors: A
authors: Hensel
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D044946:Biflavonoids / Q000737:chemistry / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D000080867:Gingipain Cysteine Endopeptidases; D006801:Humans; D062105:Molecular Docking Simulation; D010518:Periodontitis / Q000188:drug therapy*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D016966:Porphyromonas gingivalis / Q000187:drug effects* / Q000502:physiology; D044945:Proanthocyanidins / Q000737:chemistry / Q000494:pharmacology*; D031804:Rumex / Q000737:chemistry*
chemical_list: D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D044946:Biflavonoids; D000080867:Gingipain Cysteine Endopeptidases; D010936:Plant Extracts; D044945:Proanthocyanidins; C479580:procyanidin B2; D002392:Catechin; C062669:epicatechin gallate; D003546:Cysteine Endopeptidases