Purpose:
To examine the phytochemical constituents and verify the ethnomedical claim of
Newbouldia laevis
(P.Beauv.) Seeman ex Bureau Bignoniaceae in treating septic wounds and eye problems.
Methods:
Applying standard methods, the phytochemical constituents of the stem bark were examined while the antibacterial potentials of the methanol extract of the stem bark and its organic solvent fractions were tested on clinical bacterial isolates from infected wounds and eyes using the agar -well diffusion method. Ciprofloxacin and gentamicin were used as standard controls. The time-kill kinetics of the methanol stem bark extract and ciprofloxacin were determined using isolates of
Staphyloccocus aureus
.
Results:
Phytochemical screening of the stem bark revealed the presence of flavonoids, tannins, saponins and alkaloids with no traces of cyanogenic glycosides. The 65 bacterial pathogens isolated included
Proteus mirabilis
(26.0 %) and
Pseudomonas aeurginosa
(17.4 %) from non-diabetic patients’ wounds;
Staphylococcus aureus (32.0 %) and
Escherichia coli
(16.0%) from diabetic patients’ wounds;
Staphylococcus aureus (35.3%) and
Pseudomonas aeruginosa (35.3 %) from infected eyes. The chloroform fraction was observed to be more active on Gram-negative organisms while the aqueous fraction was more active on Gram-positive organisms. Time-kill kinetics of
Staphylococcus aureus showed that the extract was bactericidal (99.9 % killing) at MIC and 2 x MIC after 24 and 3 hours, respectively.
Conclusion:
The study has established that the stem bark of
Newbouldia laevis has antibacterial activities against bacterial isolates from infected wounds and eyes as claimed in ethnomedicinal practice.
