Degradation of oral biofilms by zerumbone from Zingiber zerumbet (L.)

Oral biofilms manifestated in dental plaques can lead to further pathogenically condition such as caries. In a search for a new effective anti dental plaque from natural resources, zerumbone, an essential oil component of Zingiber zerumbet (L.) (Zingiberaceae) was reported to be active against biofilms of aerobic microbes. The purpose of this study was to investigate the planktonic growth, biofilm inhibition and degradation effects of zerumbone on dental plaque initiator microbes, Streptococcus sanguinis and Lactobacillus acidophilus in an anaerobic environment. The zerumbone was isolated from Z. zerumbet using distillation technique, followed by crystallization with n-hexane. Gas Chromatography- Mass Spectrometry was applied for compound's identification. Planktonic and biofilm degradation were observed in vitro by using microdilution techniques on 96 microtiter plates to determine Minimum Inhibition Concentration (MIC₅₀) and Minimum Biofilm Eliminating Concentration (MBEC₅₀) values. Crystal violet was used as a stain and Optical Density (OD) value was measured at 595 nm with anaerobic condition. This condition was made by anaerogen gas pack in the chamber. Modification of biofilm morphology on surface was observed by Scanning Electron Microscopy (SEM) and for the preparation sample for SEM is used the coating process with carbon tip. The results showed that zerumbone has the degradation effect on S. sanguinis and L. acidophillus single spesies biofilms. The values of MBEC₅₀of zerumbone on S. sanguinis, L. acidophilus) were 0.5% v/v and 1%, respectively. SEM images showed membrane cell disruption of S. sanguinis, L. acidophilus following zerumbone exposure. Zerumbone had degradation effect on S. sanguinis and L. acidophilus biofilms and had a great potential in anti caries.