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-?), 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-? were not significantly different from baseline andplacebo 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.