Activities of Garlic Oil, Garlic Powder, and Their Diallyl Constituents against Helicobacter pylori

ABSTRACT

Chronic Helicobacter pylori disease is reduced withAllium vegetable intake. This study was designed to assess the in vivo anti-H. pylori potential of a variety of garlic substances. The garlic materials all showed substantial but widely differing anti-H. pylori effects against all strains and isolates tested. The MICs (range, 8 to 32 μg/ml) and minimum bactericidal concentrations (MBCs) (range, 16 to 32 μg/ml) of undiluted garlic oil (GO) were smaller than those of garlic powder (GP) (MIC range, 250 to 500 μg/ml; MBC range, 250 to 500 μg/ml) but greater than the MIC of allicin (4.0 μg/ml) (Table 2) present in GP. Allicin (MIC, 6 μg/ml; MBC, 6 μg/ml) was more potent than diallyl disulfide (MIC range, 100 to 200 μg/ml; MBC range, 100 to 200 μg/ml), its corresponding sulfide, but of a strength similar to that of diallyl tetrasulfide (MIC range, 3 to 6 μg/ml; MBC range, 3 to 6 μg/ml). Antimicrobial activity of the diallyl sulfides increased with the number of sulfur atoms. Time course viability studies and microscopy showed dose-dependent anti-H. pylori effects with undiluted GO, GP, allicin, and diallyl trisulfide after a lag phase of ca. 1 to 2 h. Substantial in vitro anti-H. pylori effects of pure GO and GP and their diallyl sulfur components exist, suggesting their potential for in vivo clinical use against H. pylori infections.