Evaluation of Alternative Methods to Assess the Biological Properties of Propolis on Metabolic Activity and Biofilm Formation in Streptococcus mutans.

Jorge Jesús Veloz,Luis A Salazar,Marysol Alvear

doi:10.1155/2019/1524195

Abstract

Several biological activities have been reported for the Chilean propolis, among their antimicrobial and antibiofilm properties, due to its high polyphenol content. In this study, we evaluate alternative methods to assess the effect of Chilean propolis on biofilm formation and metabolic activity of Streptococcus mutans (S. mutans), a major cariogenic agent in oral cavity. Biofilm formation was studied by using crystal violet and by confocal microscopy. The metabolic activity of biofilm was evaluated by MTT and by flow cytometry analysis. The results show that propolis reduces biofilm formation and biofilm metabolic activity in S. mutans. When the variability of the methods to measure biofilm formation was compared, the coefficient of variation (CV) fluctuated between 12.8 and 23.1% when using crystal violet methodology. On the other hand, the CV ranged between 2.2 and 3.3% with confocal microscopy analysis. The CV for biofilm's metabolic activity measured by MTT methodology ranged between 5.0 and 11.6%, in comparison with 1.9 to 3.2% when flow cytometry analysis was used. Besides, it is possible to conclude that the methods based on colored compounds presented lower precision to study the effect of propolis on biofilm properties. Therefore, we recommend the use of flow cytometry and confocal microscopy in S. mutans biofilm analysis.

Highlights

Propolis is a product collected by honeybees (Apis mellifera) and formed by the resinous excretions of buds and bark of trees and shrubs [1]
We evaluate alternative methods to assess the effect of Chilean propolis on biofilm formation and metabolic activity of Streptococcus mutans (S. mutans), a major cariogenic agent in oral cavity
Biofilm formation was studied by using crystal violet and by confocal microscopy. e metabolic activity of biofilm was evaluated by MTT and by flow cytometry analysis. e results show that propolis reduces biofilm formation and biofilm metabolic activity in S. mutans

Summary

Research Article

Evaluation of Alternative Methods to Assess the Biological Properties of Propolis on Metabolic Activity and Biofilm Formation in Streptococcus mutans. We evaluate alternative methods to assess the effect of Chilean propolis on biofilm formation and metabolic activity of Streptococcus mutans (S. mutans), a major cariogenic agent in oral cavity. Biofilm formation was studied by using crystal violet and by confocal microscopy. E metabolic activity of biofilm was evaluated by MTT and by flow cytometry analysis. When the variability of the methods to measure biofilm formation was compared, the coefficient of variation (CV) fluctuated between 12.8 and 23.1% when using crystal violet methodology. E CV for biofilm’s metabolic activity measured by MTT methodology ranged between 5.0 and 11.6%, in comparison with 1.9 to 3.2% when flow cytometry analysis was used. Erefore, we recommend the use of flow cytometry and confocal microscopy in S. mutans biofilm analysis It is possible to conclude that the methods based on colored compounds presented lower precision to study the effect of propolis on biofilm properties. erefore, we recommend the use of flow cytometry and confocal microscopy in S. mutans biofilm analysis

Introduction

Materials and Methods

Results

DMSO Control