Effect of xylitol tablets with and without red propolis on salivary parameters, dental biofilm and sensory acceptability of adolescents: a randomized crossover clinical trial.

The effect of xylitol tablets with (XPT) and without (XT) red propolis on salivary parameters, dental biofilm and acceptability of adolescents was evaluated through a blinded randomized crossover clinical trial. Healthy volunteers were allocated in the XPT and XT groups with a 30-day washout period for consumption of two tablets/dayfor seven days. An increase in salivary parameters was only observed immediately after tablet consumption, without differences between XPT and XT. The results for total microorganisms were similar, but XT was better in controlling Streptococcus spp. Rothia dentocariosa and Streptococcus salivarius were the most frequent in the biofilm and saliva, respectively. XPT and XT showed similar acceptability, with the highest purchase intention for XT. Although propolis did not enhance the properties of XT, further studies testing different protocols and follow-up are necessary; XT controlled Streptococcus spp. in biofilms, which demonstrate its potential for clinical application.

Cytotoxic and antibacterial effect of a red propolis mouthwash, with or without fluoride, on the growth of a cariogenic biofilm.

OBJECTIVE: To evaluatein vitro the antibacterial activity, the antibiofilm effect and the cytotoxic potential of mouthwashes containing Brazilian red propolis with or without fluoride. METHODS: The minimum inhibitory and bactericidal concentrations (MIC and MBC) against S. mutans, S. sanguinis, S. salivarius and L. casei were determined for RPE mouthwashes. A cariogenic biofilm with the aforementioned bacteria was formed over cellulose membrane disks (N = 30, 13 mm), which were submitted for 1 min to the following mouthwashes: plain mouthwash base; 0.05% NaF; 0.8% RPE; 0.8% RPE + 0.05% NaF and 0.12% chlorhexidine (CHX). The bacterial viability and the production of extracellular polysaccharide (EPS) were measured. Cytotoxic potential of the mouthwashes was also evaluated. For bacterial viability and EPS production, Mann-Withney and one-way ANOVA tests were performed followed by Tukey, with results considered significant when p ≤ 0.05. RESULTS: MIC and MBC values of RPE mouthwashes ranged from 7.44 to 29.76 mg/mL and from 7.44 to ≥59.52 mg/mL, respectively, presenting better action against S. salivarius. RPE mouthwashes showed 44% of viable cells after 1 min of contact with fibroblasts. RPE (7.74) had the greatest reduction of viable total microorganisms and did not differ from the RPE + NaF (7.95) (p = 0.292). CHX (7.54) was the most effective in reducing Streptococcus spp, but did not differ from RPE (p = 0.521) and RPE + NaF (p = 0.238). There was no difference between the treatments regarding EPS production. CONCLUSION: RPE and RPE + NaF mouthwash showed similar antibacterial activity, toxicity level and antibiofilm effect compared to CHX.

Antibacterial and Cytotoxic Potential of a Brazilian Red Propolis

Objective: To evaluate in vitro the effect of a red propolis ethanolic extract (RPE) in the prevention of growth of a cariogenic biofilm and its cytotoxic potential. Material and Methods: Minimum inhibitory and bactericidal concentrations (MIC and MBC) of RPE against Streptococcus mutans and Lactobacillus casei were determined. The cytotoxic potential of 0.4% RPE in oral fibroblasts was observed after 1, 3 and 5 min of contact. Cellulose membrane disks (13 mm, N=12) were used for biofilm formation (24 h) of S. mutans and L. casei, which were treated (1 min) with 0.4% RPE or 0.12% Chlorhexidine (CHX). The control group of biofilm formation was not submitted to any treatment. Serial dilutions were then made to evaluate microbial viability. Descriptive data analysis and, for microbial viability, Mann Whitney test were performed (p≤0.05). Results: RPE showed similar MIC and MBC (4.46 mg/mL) against S. mutans and, for L. casei, they were 8.92 mg/mL (MIC) and 17.85 mg/mL (MBC). CHX presented MIC and MBC <0.00002 mg/mL for S. mutans and 0.00047 mg/mL for L. casei. After 1, 3 and 5 min, the RPE exhibited, respectively, 69.38%, 43.91% and 40.36% of viable cells. The RPE (6.55) and CHX (6.87) presented similar efficacy to reduce the total number of viable bacteria (p>0.05). Regarding the total number of viable bacteria (Log10 CFU/mL), the RPE (6.55) and CHX (6.87) presented similar efficacy (p>0.05). Conclusion: Red propolis extract showed antibacterial activity against the tested strains, exhibited acceptable cytotoxicity and reduced the colonization of S. mutans and L. casei in a biofilm membrane model.