Antimicrobial activity of root extract and crude fractions of Croton zambesicus.

The root extract and fractions of Croton zambesicus were screened for antimicrobial activity against some typed and pure cultures of bacterial and fungal species. These were carried out by the Plate-hole diffusion method on Mueller-Hinton agar (MHA) for bacteria and Sabouraud Dextrose Agar (SDA) for the fungi. The Minimum Inhibitory Concentrations (MICs) of test samples found to be active by the diffusion test were determined based on the macrodilution method. The crude extract as well as chloroform and n-hexane fractions had activity against B. subtilis only. While ethyl acetate fraction had a wide spectrum of activity against all the bacteria organisms tested with a promising minimum inhibitory concentrations. However, the crude extract and the fractions were inactive against all the fungal species tested. This result confirms its ethnomedicinal use in the treatment of microbial infections.