Study on antibacterial effect of some Allium species from Hamedan-Iran

Abstract

Garlic and onion belonging to family Alliaceae are well known for having antibacterial effects. The antibacterial effects of six native Allium spp. were examined. Aqueous extracts were prepared from different parts of plants and six different bacterial isolates comprising of both Gram-negative and Gram-positive organisms were used. All extracts exhibited antimicrobial activities at a concentration 10 mg mL. The highest zones of inhibition were exhibited by Allium atroviolaceum extract ranging from 6.4 to 42.6 mm. Inhibition zones of the other species were: A. eriophyllum 3.5 45 mm, A. scabriscapum 0.8 25.3 mm, A. stamineum 7.2 39.7 mm, A. iranicum 0 30 mm and A. shelkovnikovii 0-27.8 mm. In bulbous plants, the bulb extracts had stronger antimicrobial activity and in others, flower extracts were more effective. Among the tested organisms Klebsilla pneamoniae was the most resistant and Bacillus subtilis and B. cereus were more sensitive than others. Minimum inhibitory concentration (MIC) in A. atroviolaceum was nearest to that of Streptomycine, while MIC of A. shelkovnikovii was farther from it.