The effect of garlic powder on human urinary cytokine excretion.

PURPOSE To evaluate the effects of orally administered dehydrated garlic powder on cytokine excretion in the urinary tract. MATERIALS AND METHODS A total of 60 healthy volunteers, randomized into 3 groups, were given a single oral dose of 1 g or 3 g of dehydrated garlic powder or placebo. Urine samples were obtained 6.0 and 24.0 h after garlic intake and assayed for interleukin-8 (IL-8), interleukin- 12 (IL-12), tumor necrosis factor-alpha (TNF-α), diallyl disulfide (DADS) and diallyl sulfide (DAS). RESULTS Significant increases in IL-12 levels over baseline were noted in urine samples obtained after oral intake of 1 g and 3 g of garlic powder (P < .001). In the 1 g and 3 g garlic powder treatment groups, time-dependent variations in IL-12 levels over the study period were significantly different from the placebo group (P < .001). In both garlic treatment groups, urinary levels of IL-8 and TNF-α were not significantly different from baseline and placebo levels (P > .017). DADS and DAS were not detected in the urine samples at any time after garlic powder intake. CONCLUSION Oral intake of doses of garlic traditionally used for daily supplementation increases urinary levels of IL-12, which is a potent stimulator of T helper cell 1 (Th-1) immune responses. This observation encourages further studies investigating the immunostimulatory role of garlic in the urinary tract.