2008 Volume 25 Pages 76-80
Mimosine (3-hydroxy-4-oxo-1 (4H)-pyridinealanine), a tyrosine analogue is produced by plant Leucaena leucocephala. Cytotoxic effects of mimosine were analyzed in relation to the generation of reactive oxygen species. 1. Treatment of glioma C6 cells with mimosine induced cell death with DNA damage and repair processes. 2. Mimosine/iron complex inactivated aconitase, the most sensitive enzyme to oxidative stress. The inactivation was dependent on sodium azide, an inhibitor of catalase, indicating that mimosine/iron complex can generate hydrogen peroxide as a principal product. 3. Mimosine stimulated the atuooxidation of Fe2+ suggesting that mimosine promotes the activation of dioxygen molecule by reduced iron. 4. Mimosine enhanced the Fe/ascorbate-dependent formation of 8-hydroxy-2ʼ-deoxyguanosine in DNA, indicating generation of hydroxyl radical. Prooxidant action of mimosine may explain the cytotoxic effects of this compound including alopecia and growth retardation reported previously.
