# Propolis as Natural Product in the Oral Cavity Bacterial Infections Treatment: A Systematic Review
## 4 Results
### Antibacterial Activity of Propolis in Oral Cavity Bacterial Infections
#### 4.2.1 In Vitro Studies
The samples were collected in Poland. The results showed that the extract of Polish propolisis affected salivary _S. mutans_ and _Lactobacillus spp_. viability, exhibiting an antibacterial efficacy on them, while _Lactobacillus spp_. were more susceptible to EEP. The authors estimated MIC and MBC values (Table 3). The results they obtained suggest that antibacterial substances with propolisis could locally affect cariogenic bacteria [70]. [PERSON] et al. [71] tested the _in vitro_ activity of alcoholic and hydrolysate extract of propolisis against _S. pyogenes_. The authors also evaluated the _in vitro_ activity of a combination of propolisis and its active ingredients (galangin, pinocembrin, chrysin, quercetin, caffeic acid phenethyl ester, ferulic acid phenethyl ester, and farnesol) and some beta-lactams, macrolides, and fluoroquinolones. The results did not demonstrate a synergistic activity between antibiotics, propolisis, and its constituents. The obtained MIC value of propolisis hydroglyceric extract for _S. pyogenes_ is presented in Table 3[71]. [PERSON] et al. [72] used propolisis samples from Chile to determine their chemical and botanical characteristics. The authors evaluated how _S. mutans_ and _S. sobrinus_ are biologically affected by propolisis. Beekeepers from the central and southern regions of Chile supplied twenty propolisis samples for testing. The MIC was determined on _S. mutans_ and _S. sobrinus_. In all propolisis samples, mainly structures from native plant species were detected. A wide spectrum of action was recorded, although the growth of _S. mutans_ was inhibited by all propolis samples (Table 3) [72]. [PERSON] et al. [73] evaluated _in vitro_ the synergistic effect between the ethanol extract of different Brazilian propolisids samples: green (_Baccharis dracunculifolia_) (A), red (_Dalbergia ecastophyllum_) (B), and brown (_Copafera sp._) (C) propolisids by the antimicrobial sensitivity of _S. mutans_ and _S. sanguinis_. The results showed that all extracts inhibited the growth of both microorganisms. These results were obtained based on measuring inhibition zones after 24 h and 48 h. The inhibition zones after 24 h were 21.50 \(\pm\) 0.50 (A), 27.25 \(\pm\) 0.25 (B), 21.00 \(\pm\) 0.0 mm (C) for _S. mutans_, and 16.67 \(\pm\) 1.09 (A), 19.33 \(\pm\) 0.94 (B), 15.67 \(\pm\) 0.19 mm (C) for _S. sanguinis_, respectively. The inhibition zones after 48 h were 21.50 \(\pm\) 0.50 (A), 27.25 \(\pm\) 0.25 (B), and 21.00 \(\pm\) 0.0 mm (C) for _S. mutans_, and 16.67 \(\pm\) 1.00 (A), 19.33 \(\pm\) 0.94 (B), and 15.67 \(\pm\) 0.19 mm (C) for _S. sanguinis_, respectively [73]. [PERSON] et al. [74] investigated how the antibacterial and mechanical properties of conventional glass ionomer cement (GIC), used in orthodontic band cementation, would be affected by ethanolic extracts of propolis (EEP). Four types of GIC were analyzed: one using the original composition (without EEP) and three with addition EEP (10, 25, and 50%). The authors showed that EEP in concentrations of 25 and 50% inhibited the growth of _S. mutans_, while EEP in the concentration of 10% and control group showed no impact on _S. mutans_. The obtained MIC values for EEP are presented in Table 3. Interestingly, the MIC values for GIC and EEP were much higher (31.2 ug/mL for GIC + 50% EEP, 125 ug/mL for GIC + 25% EEP, and \(>\)1000 ug/mL for GIC + 10% EEP) than those for EEP only. It suggests that EEP possesses much better antibacterial activity toward _S. mutans_[74]. [PERSON] et al. [75] added to a chitosan polymeric base (CHV), ethanolic propolis extract in various concentrations of propolis varnishes (PV): PV1 (5%), PV2 (10%), and PV3 (15%). The researchers could conclude that the antimicrobial properties of propolis were maintained even when propolis was incorporated into the coating of chitosan. The authors indicated that the antimicrobial activity of propolis varnishes against _S. mutans_, _S. sanguinis_, _S. salivarius_, and _L. casei_. The MIC and MBC values are presented in Table 3[75]. [PERSON] et al.