Antibacterial activity of berry juices, an in vitro study

Abstract

Objective. The aim of the present study was to evaluate in vitro antibacterial activities of blackcurrant and sea buckthorn juices on bacteria associated with gingival inflammation. Materials and methods. The growth of selected bacteria (Streptococcus mitis, Streptococcus mutans, Streptococcus sanguinis, Streptococcus gordonii, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa) was studied in vitro on agar plates. The content of phenols in the different extracts was measured with HPLC-ESI-MS. Results. The spectrometric analysis identified that the highest level of the single phenols studied was found for ferulic acid (113 μg/ml) in blackcurrant juice. Sea buckthorn contained low levels of selected phenols. Total bacterial inhibition for all bacterial species studied was found at 20% berry juice concentration with pH varying between 4.1–5.4. Conclusions. The present study identified that in vitro bacterial growth on agar plates was inhibited by blackcurrant and sea buckthorn juices and that low juice pH explains bacterial in vitro growth. This may have clinical implications in biofilm development, reducing the risks for both tooth decay and gingivitis.

Key Words:

• berries
• microbiology
• pH
• polyphenols
• periodontal disease

Acknowledgments

We wish to thank Kimmo Rumpunen and Anders Ekholm at the Swedish University of Agricultural Sciences for their support.

Declaration of interest: The authors report no conflicts of interest. The study was funded by the University of Kristianstad, Sweden.