# Comparison of the Biological Potential and Chemical Composition of Brazilian and Mexican Propolis
## 3 Discussion
### Antibacterial Activity  
From the analysis of articles published in the last ten years, graphs were generated to show the number of bacterial species treated with different concentrations of extracts (Figures 2 and 3). Figure 2A shows that among the 3 colors of Brazilian propolisis represented, the red propolisis had a broader antibacterial activity, affecting more species. This type of propolisis was the most studied one in the last decade, followed by the green and brown propolisis extracts, respectively. Red propolisis was characterized in the first decade of the 2000s; thus, more related scientific works emerged. Brown propolisis had a very low spectrum of species affected, and the ethanolic extract of green propolisis had an intermediate range. All supercritical extracts had a low variability of species affected. Figure 2B shows the MICs grouped in 5 different intervals. Regarding the distribution of the MICs, it was verified that the supercritical extract (Sc) of brown propolisis inhibited microorganisms only in the 400-1600 ug/mL concentration range (Figure 2B). The ethanolic extract (Et) of green propolisis had a good inhibitory effect in low concentrations, as more than half of occurrences was on the 3.8-250 ug/mL interval. The red propolisis extracts, mainly the ethanol extracts, had a higher MIC spectrum (3.8 to 250 ug/mL), followed by the green and brown propolisis extracts, although 2 thirds of occurrences were in the 3.8-250 ug/mL range. The Sc extract was not so effective in all the 3 colors of propolisis. Scientific work related to the Mexican propolisis extracts is limited for alcoholic (methanolic and ethanolic) and aqueous extracts. The ethanol extract was the most used one to verify the antibacterial activity of propolisis, reaching a total of 16 species (Figure 3A). The ethanol extract showed a higher MIC spectrum when compared to other types of extracts (Figure 3B). The methanolic extract had all its MIC on the 100-512 ug/mL range, and the aqueous extract was only effective in high concentrations (7500-30,000 ug/mL). In comparison with the Brazilian propolisis, the ethanolic extract of Mexican propolis was also the most used one, but Mexican propolisis was effective in higher concentrations. Many variables interfere with the antibacterial capacity or potential of a propolisis extract, mainly geographic region, flora, and the species of bee. Some studies indicated that the compounds found in propolisis extract act on the cell wall of bacteria and the function of the ribosome-inhibiting protein synthesis and consequently bacterial growth (cell division), and disorganize the cytoplasmic membrane and cell wall, causing partial bacteriolysis (permeability alteration). The antibacterial mechanism is associated with chemical compounds of propolisis already described in the literature as presenting biological activities, such as phenolic compounds/flavonoids (pinocombrin, galantine, caffeic acid, pinobanksin, artemisinin C, Fruit acid, umbellic acid, p-coumaric acid, kaempfer, catechchin, epictactin, formonentein, isoformontein, luteolin, naringenin, calyosin, quercetin, and others) [12; 35; 37; 44; 56; 89; 90]. In Figures 4 and 5, the antimicrobial effects of Brazilian and Mexican propolisis in Gram-positive and -negative bacteria were compared according to the distribution of the minimal inhibitory concentrations (MICs). In scientific articles carried out with Brazilian propolisis, it was observed that the Gram-negative bacteria were significantly affected by the action of different extracts applied at concentrations up to 1600 ug/mL. The Gram-positive bacteria show a greater variation in MICs, where supercritical extracts reach the concentration range of 400-1600 ug/mL. EtGP, EtRP, and ScRP extracts have a higher frequency of inhibition concentrations between the range of 50 to 250 ug/mL.