Antibacterial activity of fermented and non-fermented virgin coconut oil against porphyromonas gingivalis and aggregatibacter actinomycetemcomitans: an in vitro study / Yuliana Ayob

Periodontal disease is associated with the presence of periodontopathogenic microorganisms such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. The elimination of these bacteria requires mechanical instrumentation by scaling and root debridement (SRD). However, residual dental biofilm requires adjunctive treatment to SRD to achieve complete removal of biofilm, hence improving periodontal health. Several delivery agents have been used to inhibit these bacteria’s growth, but natural remedy is offered as an alternative to synthetic material with minimal or no side effects and better patient acceptance. Virgin Coconut Oil (VCO) is growing interest and applied in food, industrial, skincare and medicinal fields. This study aims to determine the antibacterial effect of fermented and non-fermented VCO against P. gingivalis (ATCC 33277) and A. actinomycetemcomitans (ATCC 43718) by measuring antimicrobial susceptibility testing (AST), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), VCO cytotoxicity effect and SEM morphological changes. The selected concentrations of fermented and non-fermented VCO were 12.5%, 25% and 50%. The negative control was 10% dimethyl sulfoxide (DMSO), and the positive control was 0.12% chlorhexidine digluconate (CHX). After that, the MIC values obtained from the fermented (3.13%) and non-fermented VCO (1.56%) were used to investigate their safety on normal human gingival fibroblast cells (hGF) via cytotoxicity test using MTT assay for the duration of 12, 24 and 48 hr. Samples that exhibit MIC were observed under scanning electron microscope (SEM). Results showed that 50% of non-fermented VCO exhibit the highest AST with the inhibition zone diameter of 14.78±2.59 mm and 14.56±0.88 mm for P. gingivalis and A. actinomycetemcomitans, respectively. AST was observed at all concentrations for non-fermented VCO and only at a concentration of 50% for fermented VCO. The highest bacteriostatic and bactericidal effects recorded non-fermented VCO with MIC of 1.56% on P. gingivalis and A. actinomycetemcomitans, MBC of 3.13% on A. actinomycetemcomitans while fermented VCO showed MBC 3.13% for P. gingivalis. The MICs of fermented VCO were 3.13% and 6.25% for P. gingivalis and A. actinomycetemcomitans, respectively. The cytotoxicity test showed the percentage of viable cells in hGF exposed with fermented VCO, this demonstrated more than 85% at the 3.13% concentration for the duration of 12, 24 and 48 hr. Morphologic configurations of bacterial cells that were observed under SEM showed alteration in the bacterial cell’s configuration and cell shrinkage. VCO was proven to exhibit antibacterial activity against A. actinomycetemcomitans and P. gingivalis and would be an added benefit adjunct to SRD.