The objective of the study was to test the antibacterial activities of crude extracts of roots and leaves of Aloe gilbertii Reynolds against clinical pathogens. The crude extracts were prepared via maceration technique employing n-hexane, acetone, chloroform, dichloromethane: methanol (50:50% V/V) and methanol solvent system. The phytochemical screening tests of the dichloromethane: methanol (50:50% V/V) root extract of A. gilbertii revealed the presence of alkaloids, glycosides, phenols, flavonoids, anthraquinones and terpenoids. In the same way, the phytochemical tests of dichloromethane:methanol (50:50% V/V) leaf extract of the same plant revealed the presence of alkaloids, saponins, phenols, flavonoids, anthraquinones and steroids. Antibacterial activities of both plant parts were tested against four bacterial strains namely Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, and Escherichia coli using the agar well diffusion method. Root extracts were found to possess better growth inhibitory activities against all the bacterial species. The zones of inhibition were in the ranges of 8-23 mm and 8-18 mm, for the root and leaf extracts, respectively. The finding of the study could justify the use of the Aloe gilbertii Reynolds in traditional medicine for the treatment of various human illnesses caused by bacterial organisms; however, further investigations are needed.

Keywords: Antibacterial activity, phytochemical screening, Aloe gilbertii, leaf and root extract.