After standing for 30 minutes, the Petri dishes were incubated in an inverted position at 37°C for 18 to 24 hours for bacteria and 24°C for 48 to 72 hours for yeasts. The diameters of the zone of inhibition (ZIH), defined by the clear area devoid of growth, was measured twice. The antimicrobial activities were determined by the ratio of the ZIH diameters of the extracts to that of the standard anti-biotic in the same Petri dish, whereby a higher ratio indicates a more potent extract.