Macrophages play an important role in host defenses against tumors by killi
ng them and produce secretory products, which were resulted in the protecti
on against bacterial, virus infection and malignant cell growth. Allicin, t
he major component of Garlic (Allium sativum) was examined for the ability
to induce secretory and cellular responses in murine peritoneal macrophages
. When macrophages were treated with various doses (1, 10, 100 ng/ml) of al
licin for 20 hr, allicin induced tumoricidal activity and increased the pro
duction of tumor necrosis factor (TNF-alpha), and nitric oxide (NO) in a do
se-dependent manner. However, there was a little alteration on phagocytosis
and the production of hydrogen peroxide (H2O2), interleukin-1 (IL-1), and
IL-6. These results indicate that NO and TNF-cr are likely major mediators
of tumoricidal activity in allicin-treated macrophages. Taken together our
data suggest that allicin is an efficient immunomodulator of macrophage sec
retory and cellular activities, showing a differential effect on production
of cytokines and cytotoxic molecules. (C) 2001 Elsevier Science Inc. All r
ights reserved.