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

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.

Antibacterial, antibiofilm, and cytotoxic activities and chemical compositions of Peruvian propolis in an in vitro oral biofilm

“…The PCR results showed that the concentration of 1,563 mg/mL of the methanolic fraction of propolis decreased the copy numbers of the srtA gene of S. gordonii and the radD gene of F. nucleatum at 120 hours. Although no previous studies have evaluated the effect of propolis on biofilms of these species, some research suggests that propolis has a dosedependent effect on the inhibition of genes involved in adherence, showing a potential effect beyond bacterial growth inhibition (Veloz et al, 2019a(Veloz et al, , 2019b.…”

“…The diverse chemical compositions of propolis reflect its advantage as an antibacterial agent (Abbasi et al, 2018;Almuhayawi, 2020;Asawahame et al, 2015;Cardoso et al, 2016;Chen et al, 2018;Lupatini et al, 2016;Martins et al, 2018;Oryan et al, 2018;Pasupuleti et al, 2017;Przybyłek & Karpi nski, 2019;Utispan et al, 2017;Veiga et al, 2017;Veloz et al, 2019b;Zabaiou et al, 2017). Despite efforts to investigate its pharmacological properties, no studies have evaluated the action of Peruvian propolis on bacteria present in periodontal biofilms.…”

Evaluation of Cytotoxic and Antimicrobial Properties of Iranian Sea Salts: An In Vitro Study

“…By adding ethanol (95%) (125 μ L) to each well, biofilm formation was determined. With a microplate reader, the optical density of wells (OD) was measured in comparison to the control biofilm (without sea salt) at 590 nm [ 19 ]. The mean absorbances of the samples were assessed, and by the following formula, the percentage inhibition gained for the sea salt solutions at different concentrations was measured: where OD treatment and OD control refer to the absorbance at 570 nm in each well with and without the samples, respectively, after the addition of the dissolving solution.…”

“…e stock culture of C. albicans was inoculated initially into sterilized yeast peptone dextrose (YPD) broth to form the C. albicans suspension. A concentration of 1.0 × 10 5 CFU/mL was used for the MIC assay (18,19).…”

Antibacterial, antibiofilm, and cytotoxic activities and chemical compositions of Peruvian propolis in an in vitro oral biofilm

“…The diverse chemical compositions of propolis reflect its advantage as an antibacterial agent ( Abbasi et al ., 2018 ; Almuhayawi, 2020 ; Asawahame et al ., 2015 ; Cardoso et al ., 2016 ; Chen et al ., 2018 ; Lupatini et al ., 2016 ; Martins et al ., 2018 ; Oryan et al ., 2018 ; Pasupuleti et al ., 2017 ; Przybyłek & Karpiński, 2019 ; Utispan et al ., 2017 ; Veiga et al ., 2017 ; Veloz et al ., 2019b ; Zabaiou et al ., 2017 ). Despite efforts to investigate its pharmacological properties, no studies have evaluated the action of Peruvian propolis on bacteria present in periodontal biofilms.…”