ABSTRACT
Objective: To evaluate the antibacterial activity of Cinnamomum verum (C. verum) from 32 different essential oils against cariogenic bacteria, Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus). Methods: The antibacterial activities of each essential oil were individually investigated against S. mutans and S. sobrinus. The essential oil of C. verum was selected for further evaluation against S. mutans and S. sobrinus. Gas chromatography mass spectrometry was used to determine the major constituents of C. verum essential oil. In addition, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration of the most effective constituent was investigated. Results: The essential oil from C. verum exhibited the greatest antibacterial activity. Gas chromatography mass spectrometry analysis revealed that the major components of C. verum essential oil were cinnamaldehyde (56.3%), cinnamyl acetate (7.1%) and β-phellandrene (6.3%). The MIC of cinnamaldehyde was measured using broth dilution assays. The MIC of cinnamaldehyde was 0.02% (v/v) against both bacterial strains tested. The minimum bactericidal concentration of cinnamaldehyde against S. mutans and S. sobrinus were 0.2% and 0.1% (v/v), respectively. Conclusions: The essential oil of C. verum and its major component cinnamaldehyde possessed considerable in vitro antibacterial activities against cariogenic bacteria, S. mutans and S. sobrinus strains. These results showed that the essential oil of C. verum and its bioactive component, cinnamaldehyde, have potential for application as natural agents for the prevention and treatment of dental caries.
ABSTRACT
Cankers are localized dead areas in the bark of stems, branches or twigs of many types of trees and shrubs, and are usually caused by fungi. We observed severe canker symptoms in oak trees located in Gyeongnam province in 2011. A total 31 trees were discovered with cankers of varied size, with an average of 48.5 x 15.2 cm. Black, half-rounded globular mound shaped stromata were associated with the cankers, and the asci of the fungi associated with the cankers were cylindrical shaped with their spore-bearing parts being up to 84 microm in length. The average fungal ascospores size was 7.59 x 4.23 microm. The internal transcribed spacer sequence for the canker causing fungus showed 99% similarity to the sequence of Annulohypoxylon truncatum. In this study, the isolated fungus was precisely described and then compared with fungi of similar taxa.