Effect of Kiwifruit and Blueberry Extract Against Bacterial VSC Production

Objectives: Some food products are known to be effective in controlling oral malodor. Oral malodor is mainly caused by volatile sulfur compounds (VSC) produced by peridontopathogenic bacteria. The aim of this study was to investigate the influence of VSC production by Fusobacterium nucleatum (Fn) using the kiwifruit extract and the blueberry extract as VSC-inhibiting substances.
Methods: The kiwifruit extract powder was provided by Institute of Health Sciences, Ezaki Glico Co., Ltd., Japan and the blueberry extract powder was kindly provided by Diana Food, France. Microplate dilution assay was used to determine the inhibitory concentration of substance against the growth of Fn. VSC analysis was performed as follows: Fn ATCC25586 was grown anaerobically and Fn biofilm on membrane filter (13-mm in diameter) was prepared. It was pretreated with the extract solution or PBS (control), then the membrane was incubated with 3 ml of 2 mM L-methionine at 37°C for 20 min in a sealed tube. CH₃SH production in the tube was measured by Oral Chroma^TM.
Results: The ability of the extract to interfere with the growth of Fn was assessed. The kiwifruit extract and the blueberry extract showed significant effects at the minimal concentration of 500 μg/mL and 250 μg/mL, respectively. The effect of extracts on VSC production of Fn was also evaluated by comparing with control. The kiwifruit extract at the concentration of 125, 250 and 500 μg/mL inhibited the CH₃SH production significantly. The blueberry extract was able to inhibit CH₃SH production significantly at 500 μg/mL.
Conclusions: These results suggest that the kiwifruit extracts are effective in inhibiting bacterial VSC productions. Therefore, this extract is effective in reducing oral malodor.