Evaluation of bio-compatibility and effectiveness of propolis Tetragonula sp. as dental anti-microbial agent

Introduction
Bacterial invasion is an important concern in dental therapy procedures. Oral bacteria, such as Enterococcus faecalis (E. faecalis) and Streptococcus mutans (S. mutans) could be more virulent in dysbiosis condition. Utilization of anti-microbial agent, e.g., chlorhexidine digluconate (CHX), is commonly applied for bacterial control in dental practice, since it harbors significant bacterial eradication. However, bio-compatibility concerns arise along with chemical anti-microbial agent towards surrounding tissues. Propolis, with its’ various bio-active compounds is reported to inhibit bacterial growth without artificial chemical substance, and making it as a promising alternative anti-microbial agent.

Objectives
This study aimed to evaluate anti-bacterial capacity of the propolis compound and its’ cyto-toxic effects against human fibroblast.

Material and methods
0.1% and 1% of both ethanolic- (EEP) and water-based (WEP) compounds of local propolis were prepared prior to experimental procedures. Both E. faecalis ATCC 29212 and S. mutans ATCC 25175 were measured at 625 nm for McFarland’s initial adjustment, and turbidity at 600 nm for growth evaluation and anti-bacterial activity. Cyto-toxic effects of both extracts towards fibroblast cells were evaluated through cells viability test using MTS method. Shapiro-Wilk test was performed followed by ANOVA, t-test, or Mann-Whitney U-test.

Results
It showed that the EEP tended to be more toxic than the WEP against human fibroblast cells in higher concentrations. Both 1% of WEP and EEP showed significant bacterial inhibitory activities against E. faecalis and S. mutans.

Conclusions
These findings suggest the enhanced possibility of propolis-based compound as a promising dental anti-microbial agent.