Violacein cytotoxicity and induction of apoptosis in V79 cells.

Violacein, a pigment produced by Chromobacterium violaceum, is reported to be a potential drug for the treatment of Chagas' disease. Violacein is also effective against leukemia and lymphoma cells in culture (IC₅₀ 10⁻⁸ M). Changes in the nuclear acid content, 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide reduction and neutral red uptake in these cells were used to evaluate the cytotoxicity of violacein in V79 Chinese hamster (M-8) fibroblasts. Violacein was highly cytotoxic to V79 fibroblasts (IC₅₀ 5–12 μ M). Using the TUNEL method and the Feulgen reaction coupled to image analysis, violacein (5 and 10 μ M) was found to trigger apoptosis but not necrosis in V79 cells. The morphological changes seen in the nuclei of these cells included chromatin condensation and a decrease in deoxyribonucleic acid content. These results demonstrating that violacein induces apoptosis in V79 cells strengthen its potential as a therapeutic agent. [ABSTRACT FROM AUTHOR]