ABSTRACT

Treatment of infectious disease is a major public health challenge due to the continual increase in

drug resistance by microorganisms. Plants are rich source of antibacterial agent which could be

used to treat and manage human disease.This study was carriedout to evaluate antibacterial

activity of methanolic leaf and root extracts of Ziziphus lotus on multidrug resistant E.coli, S.

aureus, Salmonella spp, and P. aeruginosa. The Plant materials were extracted with methanol

using cold maceration method and concentrated under vaccum with rotary. The crude extracts

were fractionated using n-hexane, ethyl acetate and n- butanol. The n- butanol fraction with

highest activity was partially purified using silica gel column chromatography. Antibacterial

activity of the extract was evaluated using agar well diffusion method at concentrations of 200,

100, 50 and 25mg/ml. The concentrations were prepared by dissolving 2g of each extract in 10ml

of 5% dimethyl sulphoxide and the rest were prepared by two fold dilutions. The minimum

inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined

by broth dilution and spread plate technique respectively. Ciprofloxacin (10μg) was used as

standard drug during the study while 5% Dimethyl sulphoxide (DMSO) was used as negative

control. All extracts have activity with highest against Staphylococcus aureus and least against

Escherichai coli. Phytochemical screening of the crude extracts revealed the presence of

flavonoids, alkaloids, tannins, saponins, cardiac glycosides and cyanogenic glycosides. The GC-

MS result showed the presence of Octadec-9-enoic acid, Hexanoic ac