Mast cells are involved in allergic inflammation and some rare disorders such as systemic mastocytosis and mast cell leukemia. Certain naturally occurring flavonoids have been shown to inhibit mast cell activation and promote maturation of secretory granules. Here, we report that the isoflavone genistein inhibited the growth of human leukemic mast cells (HMC-1) by 68.8, 51.6, and 30.2% at 1024 , 1025 , and 1026 M, respectively, at day 3 (p , 0.001). Genistein at 1024 M increased the histamine content per 2 3 105 cells at day 3 from 5.9 6 1.2 mg/mL to 11.1 6 1.3 mg/mL (n 5 6; p , 0.0001). These results indicate that genistein can inhibit proliferation and induce maturation of HMC-1 cells. (Allergy and Asthma Proc 24:373–377, 2003)
