Extracts of 13 Brazilian
medicinal plants were screened for their antimicrobial activity against bacteria
and yeasts. Of these, 10 plant extracts showed varied levels of antibacterial
activity.
Piper regnellii
presented a good activity against
Staphylococus aureus
and
Bacillus subtilis
,
a moderate activity on
Pseudomonas aeruginosa
, and a weak activity
against
Escherichia coli
.
Punica granatum
showed good activity on
S. aureus and was inactive against the other
standard strains.
Eugenia uniflora
presented moderate activity
on both
S. aureus and
E. coli.
Psidium guajava
,
Tanacetum vulgare
,
Arctium lappa
,
Mikania glomerata
,
Sambucus canadensis
,
Plantago major
and
Erythrina speciosa
presented some degree of antibacterial activity.
Spilanthes acmella
,
Lippia alba
, and
Achillea millefolium
were considered inactive. Five of the plant extracts presented
compounds with Rf values similar to the antibacterial compounds visible on bioautogram.
Of these, three plants belong to the Asteraceae family. This may mean that the
same compounds are responsible for the antibacterial activity in these plants.
Anticandidal activity was detected in nine plant extracts (
P. guajava,
E. uniflora,
P. granatum,
A. lappa,
T. vulgare,
M.
glomerata,
L. alba,
P. regnellii, and
P. major). The
results might explain the ethnobotanical use of the studied species for the treatment
of various infectious diseases.
