EFFECT OF ALLIUM SPP. AND HERB EXTRACTS ON FOOD-BORNE PATHOGENS, PROCARYOTIC, AND HIGHER AND LOWER EUCARYOTIC CELL LINES

Various medicinal properties have been ascribed to natural herbs. Certain food-borne bacterial pathogens were tested for their sensitivity to allicin, a major component to garlic extracts. Allicin was chemically synthesized and purified by HPLC. Its inhibitory activity against the bacteria was determined using a disc sensitivity plate assay. These pathogens included Salmonella typhimurium, Shigella dysenteriae, Clostridium perfringens, Escherichia coli, Pseudomonas aeruginosa, and Staphylo- coccus aureus. All were inhibited by allicin in a dose-dependent manner. In addition, protozoal parasites and mammalian cell lines, whose sensitivities to natural herbs was undetermined, were tested for susceptibility to aqueous and ethanol plant extracts including nutmeg (Myristicaceae spp.), ginger (Zingiber officinale), goldenseal root (Hydrastis canadensis), garlic (Allium sativum), elephant garlic (Allium scorodoprasum), onion (Allium cepa), and licorice (Glycyrrhiza glabra). Growth of cells of Leishmania chagasi 13 and Leishmania mexicana 227 was monitored after 72 hr at 590 nm in microwell plates using a microplate reader. HeLa cells, cultured in RPMI-1640 medium with 5% fetal bovine serum, were also tested. Inhibition of HeLa and leishmanial cells was expressed as the IC50 in μg/ml. L. chagasi was more sensitive to both types of garlic than L. Mexicana. Extracts from raw onion did not inhibit growth of any of the cell lines. Licorice (G. glabra) inhibited leishmanial parasites but were not toxic to HeLa cells. All the other extracts showed varying inhibitory activities.