Silvestrol produces B-cell selective cytotoxicity. (A) Silvestrol effects on isolated normal B and T lymphocytes: B cells (n = 4, 74%-88% CD19⁺) and T cells (n = 4, 81%-86% CD3⁺) were selected from peripheral blood of healthy volunteers and incubated in media with or without silvestrol. Viability was assessed at 48 hours by MTT assay and results were calculated relative to the time-matched untreated samples in each case. Bars show plus or minus SD. (B) Silvestrol effects on B and T cells in whole blood: Peripheral blood from either CLL patients (left, n = 5) or healthy volunteers (right, n = 4) was incubated at 37°C with mixing, with or without 80 nM silvestrol () or 1 μM F-ara A (). At the indicated times, an aliquot was analyzed by flow cytometry for CD19⁺ cells (striped bars) and CD3⁺ cells (solid bars). Data are shown relative to time-matched untreated samples. Bars represent plus or minus SD.