Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses

Abstract

BackgroundBlack 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.MethodsThe 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.ResultsFor 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.ConclusionRubini 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.

Assessment of colour changes during storage of elderberry juice concentrate solutions using the optimization method

“…Fruits and pomace are sources of anthocyanin pigments for the production of natural food colorants and pharmaceuticals (Seabra et al, 2010). Thanks to their high of polyphenol content, these fruits have long been ascribed anti-infl ammatory and anti-infl uenza properties (Krawitz et al, 2011), antitumour and antiatherogenic properties (reduction in triglyceride concentration and inhibition of platelet aggregation) (Wattenberg, 1990). A model study on the biological activity of anthocyanins from the elderberry plant showed their antioxidant eff ect and protective role in the inhibition of endothelial cell damage in blood vessels under oxidative stress (Youdim et al, 2000).…”

Anti-Influenza Virus Effects of Elderberry Juice and Its Fractions

“…Judging from the pharmacological and clinical effects of elderberry reported by Vlachojyannis et al, 3) almost all the effects of elderberry warrant further investigation. Several in vitro studies on the anti-IFV activity of elderberry have found the inhibition of both haemagglutination 4) and viral proliferation, 24) and prevention of the adhesion of the virus to the host cell receptors. 14) In addition, elderberry has been reported to stimulate the immune system by enhancing the production of cytokines by monocytes.…”

Disruption of virus-host cell interactions and cell signaling pathways as an anti-viral approach against influenza virus infections

“…This lack of apparent side effects would even allow long-term prophylactic use. Second, a broad and non-specifi c anti-pathogen action as shown for some polyphenolic plant products, for example cistus extracts, components of green tea or elderberry liquids, could prevent emergence of viral resistance and the compounds might also be active against opportunistic bacterial infections (Bouamama et al , 1999 ;Cheng et al , 2002 ;Krawitz et al , 2011 ).…”