Cruciferous phytoalexins: antiproliferative effects in T-Jurkat leukemic cells

We tested antiproliferative activity of selected cruciferous phytoalexins including brassinin, 1-methoxybrassinin, (±)-spirobrassin, (±)-1-methoxyspirobrassinin and (±)-1-methoxyspirobrassinol, in leukemic Jurkat cell. The most effective of the tested phytoalexins was 1-methoxybrassinin with IC 50 10 μmol l −1. However, significant effect of all phytoalexines was also determined at concentration 1 μmol l −1. In 1-methoxybrassinin-treated Jurkat cells, we found significant increase in the fraction of cells with a sub-G 0/G 1 DNA content, which is considered to be a marker of cell death by apoptosis. Apoptosis was also confirmed by the annexin V staining. In summary, 1-methoxybrassinin exerted potent antiproliferative activity probably due to cell cycle arrest and apoptosis induction.