Fig. 1

Ascorbic acid selectively kills CLL B-cells and has low toxicity toward B-cells from healthy donors (HD B-cells). Ascorbic acid’s effects are due to H₂O₂ generation and are reversed by catalase, sodium pyruvate (SP 1 mM) and the iron chelator deferoxamine (DFX). a: Viability of primary HD B-cells and CLL B-cells after 24 h of treatment with various concentrations of AA (***: p < 0.001 vs. Ctrl, CLL n = 16, HD B-cells n = 4). b: Extracellular H₂O₂ levels in the culture medium (RPMI) after 4 h of treatment with different concentrations of AA in the presence or absence of catalase (600 U/ml) or SP (1 mM) (n = 6). c: Primary CLL B-cell viability after 24 h of treatment with AA, dehydroascorbic acid (DHA) or AA 2-phosphate (Asc-2P); (n = 3) (**: p < 0.01, ***: p < 0.001 vs. Ctrl). d, e and f: Viability of CLL B-cells after 24 h of treatment with 250 μM AA in the presence or absence of DFX (100 μM) (*: p < 0.05; n = 5) (d), catalase (**: p < 0.01; n = 10) (e) and SP (1 mM) (***: p < 0.001; n = 20) (f). Data are presented as mean ± SEM