Abstract:
The effect of ethanolic extracts from different parts of Senna alata (leaf, pod,
flower, stem, root and seed) were tested in vitro against medically important bacteria such as Staphylococcus aureus. Bacillus cereus, Escherichia coli, Pseudomonas aeroginosa, Serratia marcescens, Salmonella typhimurium and
Streptococcus pyogenes. Different parts of the plant were dried and extracted with
95% ethanol. Kirby-Bauer Disk Diffusion Susceptibility Test was used to
determine the antibacterial activity of the extracts through the zones of inhibition
it create which were measured. The plant extracts were ranked according to the
degree of inhibition created. Results showed that all the plant extracts, except the
seed extract, were effective against Staphylococcus aureus (MIC of 6mg/ml) and
Bacillus cereus (MIC of 8mg/ml). All the plant extracts failed to inhibit growth
of the remaining 5 species of bacteria. The degree of susceptibility varied per
part, the leaf extract exhibited the highest antibacterial activity on both bacteria
while the root extract showed the lowest. However, the antibacterial effect of the
leaf extract was not as effective as the positive control, phenol. The results
indicate that Senna alata can help control the infection of Staphylococcus aureus
and Bacillus cereus.
