The antibacterial activity was based on disc diffusion
method (Bauer, Kirby, Sherris, & Truck, 1966) using bacterial
cell suspension whose concentration was equilibrated to a 0.5
McFarland standard. A 100 mL of each bacterial suspension
was spread on a MuellereHinton agar plate. Sterile paper
discs (6 mm diameter) were impregnated with 20 mL of each
extract dissolved in the solvent used for extraction at
125 mg/mL. The discs were allowed to dry and then placed
on the inoculated agar. Discs with the solvent used for dissolution
were used as negative control and 10 mg streptomycin
discs were used as positive controls. The plates were incubated
at 37 C for 24 h. After incubation time, zone of inhibition was
measured. The experiment was performed in triplicate.