| dc.description.abstract | Antibiotic resistance has created a renewed interest to search for new other antimicrobial
substances from various sources including medicinal plants. Since limited data is available so far
regarding the antibacterial activity of different onion varieties in Uganda, this study aims to assess
this activity. Antibacterial activity of four onion varieties (Bombay red, Malbec, Red creole, and
Texas grano) was examined on gram negative bacterium Escherichia coli. Each mature onion bulb
was homogenized by squashing in a mortar to a fine paste then 10g of each variety was dissolved
into 100ml of solvent. Two solvents were used for extraction (Ethanol and water) and experiments
were perfomed using by agar well diffusion. Wells in the media were administered using a cork
borer with a diameter of 10 mm. 200µL of the test bacteria were inoculated on the Mueller Hinton
agar. The onion extract was loaded in aseptically perforated agar wells plus positive (Erythromycin
antibiotic) and negative controls. The plates were incubated at 37C
ix
0
for 24 hours and the sterile
zones around the wells were measured. Results revealed that all the varieties had antibacterial
activity but Bombay red was the best variety, and had a higher antibacterial activity than the
positive control in the ethanol extraction. Ethanol extract was better than aqueous. According to
this study, all onion varieties have antibacterial activity, however, pharmacological standardization
and clinical assessment of this effect are essential before using onion extract as an antibiotic. | en_US |
