Background: Pithecellobium dulce
(Roxb.) Benth.,
Securidaca longepedunculata
Fresn and
Cryptolepis sanguinolenta
(Lindl.) Schlt are three plants widely used in the Togolese traditional medicine to treat microbial infections. Some
studies reported their antibacterial activity alone but until know there no data concerning their possible interaction with
conventional antibiotics. The main objective of this study was to investigate the antibacterial activity of the association
of the crude extracts of the three plants with some conventional antibiotics. We further evaluate the antioxidant and the
anti-inflammatory activities of the extracts on rat’s model.
Materials and methods:The antimicrobial activity was evaluated by the broth microdilution assay and the Fractional
inhibitory concentrations (FIC) determined by the checkerboard method. The anti-inflammatory activity was evaluated
using the Carrageenan- induced rat paw edema model. The antioxidant activities and the phenol contents were
determined by spectrophotometry.
Results: The MICs of hydroethanolic extract of plants ranged from 3.125 to 100 mg/mL on
Klebsiella pneumoniae
strains. Synergistic action was observed only with the combination of Imipenem/
P. dulce, imipenem/
C. sanguinolenta,
amikacin/
P. dulce and amikacin/
C. sanguinolenta against the ESBL negative
Klebsiella pneumoniae strain. Of the 21
associations, 15 were antagonistic on the ESBL-producing strains. The indifference effect was observed with the
combination of the extract of
Securidaca longepedunculata and the following antibiotics imipenem, amikacin,
tetracyclin, ciprofloxacin, Cefotaxim; and Sulfametoxazol+Trimethoprim. The
in vitro anti-inflammatory with
Lipoxygenase inhibition activity was best with
C. sanguinolenta extract while the
in vivo paw edema model revealed
that
S. longepedunculata was the highest reducer of paw edema. In addition white blood cells count and biochemical
parameters such as total proteins and immunoglobulins were significantly affected by the administration of plant
extracts.
Conclusion: This study revealed that the three plants although they may inhibit the bacterial growth by themselves, but
there is also a possible synergistic action with the commercial antibiotics. Further investigations are needed to identify
the active compounds and their mechanism of action.
