A low-molecular-weight fraction of bovine colostrum and milk enhances the oxidative burst activity of polymorphonuclear leukocytes.

Bovine colostrum and milk contain many immunomodulatory components. The low-molecular-weight fraction (< 10 kDa) was separated from colostrum and milk by gel filtration chromatography, and its effect on the oxidative burst of bovine polymorphonuclear leukocytes (PMNL) was investigated in vitro. The oxidative burst activity induced by Staphylococcus aureus was considerably enhanced when PMNLs were incubated with this low-molecular-weight fraction. However, phorbol 12-myristate 13-acetate did not trigger a burst after priming with this fraction. The oxidative burst activity enhanced by this fraction was reduced after heating. These results confirmed that a low-molecular-weight substance(s) of less than 10 kDa, present in bovine milk and colostrum, enhances the oxidative burst activity of PMNL.

Garlic and onion oils inhibit proliferation and induce differentiation of HL-60 cells.

Phytochemicals present in the genus Allium have potential pharmacological effects, such as antimicrobial, antithrombotic, antitumor, hypolipidaemic and hypoglycemic activities. In this present study, we examined the effects of garlic and onion oils on human promyelocytic leukemia cells, HL-60. Incubation of HL-60 with garlic or onion oil (20 microg/ml) caused a marked suppression of HL-60 proliferation; the suppression was almost identical with those obtained by all-trans-retinoic acid (ATRA) or dimethyl sulfoxide (DMSO) used as positive controls. These oils induced the generation of nitroblue tetrazolium (NBT)-reducing activity, and about 20% of the HL-60 cells became NBT positive. CD11b, another marker of the differentiation of these cells, was also significantly induced by garlic oil or onion oil. The combination of garlic or onion oil with ATRA was more effective than either alone. These data suggest that garlic and onion oils have the ability to induce differentiation of HL-60 cells into those of the granulocytic lineage.

Antithrombotic and antineoplastic effects of phyto-organosulfur compounds.

The antiplatelet activity of methyl allyltrisulfide (MATS), a component commonly present in steam-distilled garlic oil, has been demonstrated by the authors. MATS inhibits arachidonic acid cascade at the reaction site with PGH synthase. However, this enzyme catalyzes two successive reactions, from arachidonic acid to PGG2, and from PGG2 to PGH2. The present study revealed that MATS inhibited the latter reaction. In addition, our recent findings that to a promyelocytic leukemia cell HL60, Allium oils shows marked anti-neoplastic effects representing both growth suppression and differentiation activities are described. The garlic oil and onion oil showed almost equal ability in inducing the proliferation, which measured either by nitroblue-tetrazolium reducing activity assay or by flow cytometry for detecting CD11b expression. The combination use of one of these oils with all-trans retinoic acid or with dimethyl sulfoxide lead to the marked differentiation of the cells, and their effects were estimated to be synergistic.