THIOALLYL COMPOUNDS - POTENT INHIBITORS OF CELL-PROLIFERATION

S-Allylmercaptocysteine was shown to inhibit vascular smooth-muscle and umbilical endothelial cell proliferation. Inhibition was dose-dependent and affected smooth-muscle cells more than endothelial cells. S-Allylmercaptocysteine was two orders of magnitude more potent than S-allylcysteine and cells grown in its presence showed distinct changes in their phosphorylation compared to untreated controls. Among the proteins whose phosphorylation was altered were GTP-activating protein, protein tyrosine phosphatase-1B and p34(cdc2). We conclude that thioallyl compounds, natural constituents of garlic and known to inhibit malignant cells, can also reduce the proliferation of normal cells.