Abstract:
In Ethiopia, different parts of Croton macrostachyus (C. macrostachyus) are used as a
traditional medicine to take care of infectious diseases such as typhoid and measles, but
there is no documented report on the antibacterial activity of stem bark of this plant in
Ethiopia. C. macrostachyus stem bark was extracted using chloroform, methanol, and
water extraction solvents and tested for their antibacterial activities against Escherichia
coli (E. coli), clinical isolates and standard, and Staphylococcus aureus (S. aureus), clinical
isolates and standard, using agar well diffusion and broth dilution methods. The
positive control was Chloramphenicol, while dimethyl sulfoxide (DMSO) was served as
negative control. The present study showed the potent antibacterial activity of the C.
macrostachyus stem bark extract against all tested bacterial pathogens. The methanol
extract of C. macrostachyus stem bark showed the highest zone of inhibition (17+1mm)
against S. aureus (standard) and the lowest zone of inhibition (12+1) against E. coli
(clinical isolate). In this study, the minimum inhibitory concentration (MIC) and
minimum bactericidal concentration (MBC) values of 500 & 500 mg/ml, 62.5 & 125
mg/ml and 250 & 500mg/ml were obtained for water, methanol, and chloroform
extracts of C. macrostachyus stem bark against clinically isolated E. coli respectively. C.
macrostachyus stem bark extracts have confirmed antibacterial effects, mainly on E. coli
and S. aureus. Thus, C. macrostachyus stem bark could be effective for prevention of
bacterial infections and may be considered as an option to antibiotic regimens. But
further studies should be conducted with different extraction solvents and toxicity and
phytochemical analysis must be performed on these plants to use as sources and
templates for the synthesis of drugs.
