# 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
[76] examined whether upper respiratory tract infections (URTIs) could be treated and controlled with the use of propolis due to its antibacterial activity. The results proved the antimicrobial effectiveness of propolis when used for the treatment and management of bacterial URTI. In this study, propolis's extract was obtained with 70% ethanol, and serial dilutions of 0.25, 0.5, 1, 2, 4, 8, and 10 ug/mL were prepared. A total of 250 throat swabs were collected from patients (aged between 15 and 30 years) diagnosed with URTI. Only 2% had positive cultures with _S. pyogenes_. The results showed that these isolates were sensitive to propolis at all concentrations. The inhibition zone for _S. pyogenes_ was 10 mm, while the MIC value is presented in Table 3[76]. The antimicrobial activity of propolis's toothpaste and mouth'sine against supragin-gival multispecies biofilm was analyzed by [PERSON] et al. [43]. The biofilm contained _A. naeslundii_, _V. dispar_, _F. nucleatum_, _S. mutans_, and _S. oralis_. The authors tested toothpaste without propolis, toothpaste with propolis (0.9%), toothpaste with chlorhexidine (0.12%), mouth'sine with propolis (10%), mouth'sine with chlorhexidine (0.12%), and saline solution. The obtained colony-forming units (CFU) values were 5.14 \(\times\) 107 and 3.94 \(\times\) 107, and 6.49 \(\times\) 107, respectively for toothpaste without propolis, with propolis, and with chlorhexidine. In case of mouth'sine, the CFU values were 3.77 \(\times\) 108 and 4.58 \(\times\) 106, respectively, for mouth'sine with propolis and chlorhexidine. Interestingly, the CFU for the control sample (saline solution) was 3.36 \(\times\) 108 [43]. Ethanolic extract of propolis's and 0.2% chlorhexidine gluconate against oral pathogens were analyzed for their antibacterial activity by [PERSON] et al. [77]. The propolis's extract similar to chlorhexidine inhibited all of the oral microorganisms (_S. mutans_, _S. sobrinus_, _L. acidophilus_, _L. salivarius subsp. salivarius_, and _A. sisreali_) except _P. gingivalis_ and _A. actinomycetemomitans_. Interestingly, the extract was also more effective against _P. intermedia_ than chlorhexidine. The obtained MIC and MBC values are presented in Table 3. The effect of propolis's extract was not caused by adding 80% ethanol, since all strains were resistant to the ethanol [77]. The antimicrobial activity of Brazilian green wild propolisis against _S. mutans_ dental biofilm was analyzed by [PERSON] et al. [78]. Four different groups of compounds for biofilm treatment (30 mL/1 min, for 5 days) were tested: 33.3% ethanol propolisis extract, 0.12% chlorhexidine digluconate, 80% ethanol, and Milli-Q water. Each compound significantly reduced the percentage of hardness loss. The obtained CFU/biofilm values for _S. mutans_ were 7.26 \(\pm\) 0.08, 6.79 \(\pm\) 0.10, 8.00 \(\pm\) 0.05, and 8.29 \(\pm\) 0.17, respectively, for ethanol propolisis extract, chlorhexidine, ethanol, and water [78]. The antimicrobial activity of propolisis from Turkey against _S. mutans_ and _S. salivarius_ was analyzed by [PERSON] et al. [79]. The authors used ethanol, ethyl acetate, acetone, water, DMSO, and methanol extract of propolisis. The obtained MIC values of _S. salivarius_ were 1\(\leq\), 2\(\leq\), and 2\(\leq\) mg/mL, respectively, for ethyl acetate, acetone, and methanol extract. In case of _S. mutans_, the MIC values were 4\(\leq\), 1\(\leq\), 4\(\leq\), 2\(\leq\), and 4\(\leq\) mg/mL, respectively, for ethyl acetate, ethanol, acetone, methanol, and DMSO extract [79]. The antibacterial activity of Brazilian green propolisis (BGP) against oral pathogens (_S. mutans_, _S. sanguinis_, _P. gingivalis_, and _A. actinomycetemcomitants_) was analyzed by [PERSON] et al. [80]. The results indicated that BGP has antibacterial properties. The study showed that Brazilian propolisis in the concentration of 500 ug/mL significantly decreased the growth of _S. mutans_, while the concentration of 2000 ug/mL resulted in total inhibition. In case of _S.