title: Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses.
abstract: BACKGROUND
  Black elderberries (Sambucus nigra L.) are well known as supportive agents against common cold and influenza. It is further known that bacterial super-infection during an influenza virus (IV) infection can lead to severe pneumonia. We have analyzed a standardized elderberry extract (Rubini, BerryPharma AG) for its antimicrobial and antiviral activity using the microtitre broth micro-dilution assay against three Gram-positive bacteria and one Gram-negative bacteria responsible for infections of the upper respiratory tract, as well as cell culture experiments for two different strains of influenza virus.
  
  
  METHODS
  The antimicrobial activity of the elderberry extract was determined by bacterial growth experiments in liquid cultures using the extract at concentrations of 5%, 10%, 15% and 20%. The inhibitory effects were determined by plating the bacteria on agar plates. In addition, the inhibitory potential of the extract on the propagation of human pathogenic H5N1-type influenza A virus isolated from a patient and an influenza B virus strain was investigated using MTT and focus assays.
  
  
  RESULTS
  For the first time, it was shown that a standardized elderberry liquid extract possesses antimicrobial activity against both Gram-positive bacteria of Streptococcus pyogenes and group C and G Streptococci, and the Gram-negative bacterium Branhamella catarrhalis in liquid cultures. The liquid extract also displays an inhibitory effect on the propagation of human pathogenic influenza viruses.
  
  
  CONCLUSIONS
  Rubini elderberry liquid extract is active against human pathogenic bacteria as well as influenza viruses. The activities shown suggest that additional and alternative approaches to combat infections might be provided by this natural product.
authors.affiliation: Institute for Medical Microbiology, Justus-Liebig-University, Frankfurter Strasse 107, 35392 Giessen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Krawitz
authors.forename: Mobarak Abu
authors.initials: MA
authors.lastname: Mraheil
authors.forename: Michael
authors.initials: M
authors.lastname: Stein
authors.forename: Can
authors.initials: C
authors.lastname: Imirzalioglu
authors.forename: Eugen
authors.initials: E
authors.lastname: Domann
authors.forename: Stephan
authors.initials: S
authors.lastname: Pleschka
authors.forename: Torsten
authors.initials: T
authors.lastname: Hain
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000998:Antiviral Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D001424:Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D005638:Fruit; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects / Q000254:growth & development; D009981:Influenza B virus / Q000187:drug effects / Q000254:growth & development; D007251:Influenza, Human / Q000188:drug therapy / Q000821:virology; D009975:Orthomyxoviridae / Q000187:drug effects* / Q000254:growth & development; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D012140:Respiratory Tract Diseases / Q000188:drug therapy* / Q000382:microbiology; D027924:Sambucus nigra
chemical_list: D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D010936:Plant Extracts