Abstract
The aim of the study was to evaluate the antibacterial activity of essential oil extracted from Chrysanthemum boreale (C. boreale) on Streptococcus mutans (S. mutans). To investigate anticariogenic properties, and bacterial growth, acid production, biofilm formation, bacterial adherence of S. mutans were evaluated. Then gene expression of several virulence factors was also evaluated. C. boreale essential oil exhibited significant inhibition of bacterial growth, adherence capacity, and acid production of S. mutans at concentrations 0.1–0.5 mg/mL and 0.25–0.5 mg/mL, respectively. The safranin staining and scanning electron microscopy results showed that the biofilm formation was also inhibited. The result of live/dead staining showed the bactericidal effect. Furthermore, real-time PCR analysis showed that the gene expression of some virulence factors such as gtfB, gtfC, gtfD, gbpB, spaP, brpA, relA, and vicR of S. mutans was significantly decreased in a dose dependent manner. In GC and GC-MS analysis, seventy-two compounds were identified in the oil, representing 85.42% of the total oil. The major components were camphor (20.89%), β-caryophyllene (5.71%), α-thujone (5.46%), piperitone (5.27%), epi-sesquiphellandrene (5.16%), α-pinene (4.97%), 1,8-cineole (4.52%), β-pinene (4.45%), and camphene (4.19%). These results suggest that C. boreale essential oil may inhibit growth, adhesion, acid tolerance, and biofilm formation of S. mutans through the partial inhibition of several of these virulence factors.
Highlights
Dental caries, known as tooth decay or a cavity, is a plaquerelated disease of teeth and slowly progressive infectious disease in the dental area [1, 2]
We firstly investigated the antibacterial activity of the essential oil of C. boreale against S. mutans
The pH decrease was not inhibited at 0.05–0.1 mg/mL of C. boreale essential oil, when treated with 0.25 mg/mL and 0.5 mg/mL of C. boreale essential oil, the pH decrease was significantly inhibited and the inhibition levels was similar to the positive group. These results indicate that the C. boreale essential oil may inhibit the organic acid production by S. mutans
Summary
Known as tooth decay or a cavity, is a plaquerelated disease of teeth and slowly progressive infectious disease in the dental area [1, 2]. The dental caries disease is caused by specific types of acid-producing bacteria that cause demineralization and destruction of the teeth [3]. S. mutans are generally regarded as one of the primary pathogenic bacteria in dental caries [4]. The S. mutans adhere to the colonizer and accumulate on the tooth enamel surface by generation of extracellular polysaccharide from fermentable carbohydrates such as sucrose, by action of glucosyltransferases (GTFase) [1, 5]. The carbohydrate metabolism promotes bacteria aggregation to the tooth surface and acid production [1]. The produced acids initiate dissolution of the enamel surface of teeth subsequently leading to localized decalcification [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
