The polyphenol and flavonoid levels can present differences
between samples according to variations in
the extraction process, such as the area of the contact
surface relative to weight of the raw propolis, the type
of solvent used for extraction and the duration of the
extraction process, all of which may influence the
final concentrations of these therapeutic substances.
Moreover, it is very difficult to compare the results
showed by another authors due the differences in the
propolis composition, which depends on geographical
origin and seasonal effect (Bankova et al., 2000).
Among the polyphenols present in the EEP, the flavonoid
group has important therapeutic properties,
such as antimicrobial, antioxidant and anti-inflammatory
qualities. The high concentration of these
compounds in propolis may be responsible for its