Effect of fagaronine on cell cycle progression of human erythroleukemia K562 cells

Abstract Fagaronine (Fine) is a novel antileukemic drug extracted from Fagara xanthoxyloides Lam. (Rutaceae). In an attempt to know more about its mechanism of action we describe here its inhibitory activity on cell division, 3 H-thymidine incorporation and on cell cycle progression. Fine inhibits cell proliferation of K562 cells by 50% at a concentration of 3 × 10 −6 mol/1 at day 4. It stimulates incorporation of labelled macromolecular thymidine on day 1, but decreases incorporation on days 2, 3 and 4. Fine induces a cell accumulation in G2 and late-S phases. This accumulation (i) increases with Fine concentration, but a complete blockade is not observed, (ii) reaches a plateau after approximately 48 h, (iii) is reversible, whereas we have previously shown that cell growth inhibition and differentiation were not reversible.