# 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 chemical analysis of both extracts showed that the aqueous extract is characterized by higher concentration of metabolites (cumarins, saponins, alkaloids, tannins, quinones, and flavonoids) than the hydroalcoholic extract [91]. [PERSON] et al. [92] studied the antibacterial properties of the ethanolic extract of propolisis (EEP), and they used samples from Mexico. MIC assay was employed to test the compounds which were isolated. The antimicrobial screening revealed that EEP inhibited the growth of _S. mutans_, _S. oralis_, _S. sanguinis_, and _P. gingivalis_. MIC values are presented in Table 3[92]. The antibacterial effect of Iranian propolisolis and Persica mouthwashes against _S. mutans_, _S. salivarius_, and _S. sanguis_ was analyzed by [PERSON] et al. [93]. The results indicated that the propolisols sample exhibited much better antibacterial activity in comparison to Persica mouthwash. These results were obtained based on the inhibition zone and MIC determination. The zone of inhibition was 7.8 \(\pm\) 0.2, 14.0 \(\pm\) 2.7 and 12.2 \(\pm\) 0.1 mm, respectively for _S. mutans_, _S. salivarius_, and _S. sanguis_. It suggests that _S. salivarius_ was significantly more sensitive in comparison to other strains. In case of Persica mouthwash, the most sensitive was also _S. salivarius_ with the inhibition zone 24.0 \(\pm\) 2.16 mm. The obtained MIC values for propolisols are presented in Table 3.1 The obtained MIC values for Persica mouthwash were 1.4, 1.4, and 1.8 \(\upmu\)g/mL, respectively for _S. mutans_, _S. salivarius_, and _S. sanguis_[93]. [PERSON] et al. [94] assessed the antimicrobial activity of the aqueous and ethanol extracts of propolisols. The MIC values for _S. mutans_ and _L. acidophilus_ are presented in Table 3.2 In conclusion, this study determined propolisols as an effective agent against oral pathogens _S. mutans_ and _L. acidophilus_[94]. The antimicrobial effect of thirteen different Peruvian propolisis against _S. gordonii_ and _F. nucleatum_ was analyzed by [PERSON] et al. [95]. Here, 0.12% chlorhexidine was used as a control. The authors noticed that _S. gordonii_ was resistant to four samples of propolisols and _F. nucleatum_ was resistant to seven samples of propolisols. The obtained inhibition zones for chlorhexidine were 14.45 \(\pm\) 0.30 and 14.40 \(\pm\) 0.18 mm, respectively, for _S. gordonii_ and _F. nucleatum_. In case of propolisols samples, the inhibition zones were from 1.73 \(\pm\) 0.15 to 10.88 \(\pm\) 0.09 mm and 7.65 \(\pm\) 0.10 to 10.88 \(\pm\) 0.10 mm, respectively, for _S. gordonii_ and _F. nucleatum_[95]. The antibacterial effect of propolisols gel on _S. mutans_ and _L. acidophilus_ was evaluated by [PERSON] et al. [96]. The obtained results showed that in all concentrations, propolisols and _Aloe vera_ gel inhibited the growth of _S. mutans_ and _L. acidophilus_. The inhibition of _Lactobacillus_ was stronger than _Streptococcus_. The inhibition zone for propolisols gel were 8.05 \(\pm\) 0.27, 11.50 \(\pm\) 0.74, and 14.26 \(\pm\) 0.77 mm (for _L. acidophilus_) and 7.74 \(\pm\) 0.51, 8.85 \(\pm\) 1.03, and 10.81 \(\pm\) 0.70 mm (for _S. mutans_), respectively, after 24, 48, and 72 h. It is worth noting that the inhibition area of lower concentrations of propolisols and _Aloe vera_ gel was bigger than the one of other analyzed gels. This suggests the antibacterial effectiveness of a gel with propolisols and _Aloe vera_ even at low concentrations [96]. [PERSON] et al. [97] evaluated the antimicrobial activities of ethanol extracts of propolisols (EEP) from _Trigona thoracica_ against _S. mutans_ and _S. sobrius_. The results showed that the tested propolisols can be used as an antibacterial agent against investigated cariogenic bacteria. The antimicrobial activity of EEP expressed as the mean of inhibition diameter as well as MIC values were determined. The median inhibition diameter zone using EEP against _S. mutans_ and _S. sobrius_ was 14 and 18 mm, respectively. The obtained MIC values of EEP against _S. mutans_ and _S. sobrius_ are presented in Table 3[97].