The antimicrobial effect of virgin coconut oil and activated virgin coconut oil against dental caries-associated pathogens

Abstract

The present day diet is astoundingly cariogenic, owing to the fact that high food intake with plenty of fermentable carbohydrates present in them, thus causing a widespread of caries disease. Either separately or together, Streptococcus mutans and Lactobacilli are recognized as primary causative agents of dental caries. Therefore, demands of variety of treatments including alternatives in combating the action of cariogenic pathogens are always on the increase. In contemplation to improve and further develop novel antimicrobial compound, a great deal of research has gone into optimizing various components available in natural sources that might devour antimicrobial activity. Virgin coconut oil (VCO) is a case in point and has been the focus for decades as it consist of potent fatty acids that attributed to its remarkable antimicrobial features on many bacteria. Recently, a modified VCO known as activated virgin coconut oil (AVCO) also had proven to demonstrate a broad antimicrobial spectrum. Thus, present study aims to investigate the antimicrobial activities of VCO and AVCO against dental caries-associated pathogens namely Streptococcus mutans, Lactobacillus casei, and Candida albicans, as well as to examine their synergistic effects in combination with the current antimicrobial agents. In addition, this study aimed to observe the actions exerted by AVCO on the bacterial cell membrane. In this study, VCO was extracted via freeze and thaw method. The composition of fatty acids were identified using Gas Chromatography Mass Spectroscopy. The values of minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) were determined to conclude the antimicrobial activities of VCO and AVCO. The synergistic effects of AVCO upon combination with penicillin, chlorhexidine and nystatin were established using microbroth dilution method. The effects of AVCO on bacterial cell membrane and its permeability ware assessed via methods of crystal violet assay and morphological analysis. MIC values recorded for AVCO against Streptocccus mutans, Lactobacillus casei and Candida albicans were 3.13 mg/ml, 3.13 mg/ml and 1.57 mg/ml respectively. As for MBC/MFC value, 25.0 mg/ml, 3.13 mg/ml and 12.5 mg/ml was obtained against all tested pathogens respectively. However, negative results obtained for VCO’s disc diffuson test revealed the incapability of VCO in suppressing bacterial growth, thus the MIC and MBC/MFC values not proceeded. The evaluation on the synergism gives an indifference effect for the combination of AVCO and nystatin, while for the combination of AVCO and penincilin and chlorhexidine, antagonism effect were perceived. The observation on the AVCO’s action toward the bacterial cell permeability revealed that it was able to increase cell permeability. Viewing of AVCO treated cells under SEM showed some ultrastructural alterations indicating that AVCO able to disrupt the cells growth. These findings were able to backing the crucial role of AVCO as a potential antimicrobial agent, thus aid in arresting the problem of dental caries.