Cytotoxicity of extracts from Alternaria alternata against cultured tobacco BY-2 cells

摘要

The cytotoxicity of extracts from Alternaria alternata against tobacco Bright Yellow-2 (BY-2) cells was investigated by a simultaneous double-staining procedure using fluorescein diacetate and propidium iodide. The active fraction from a 10-day-old culture filtrate of the fungus was purified by ammonium sulfate precipitation, ultrafiltration, gel filtration on Sephadex G-10, and reversed-phase HPLC, in sequence. The partially purified principle appears to be heat- and acid-stable, as neither incubation at 100 deg C for 30 min nor overnight treatment at pH 2 altered the cytotoxicity. The cytotoxicity of the principle was abolished after treatment with proteinase K or trypsin, while the dithiothreitol treatment showed reduced cytotoxicity.