Alternol is purified from fermentation productions of microorganisms named as Alternaria alternata var. monosporus. The research is to investigate the apoptosis-inducing effect of
alternol on mouse lymphocyte
leukemia (L1210) cells and the possible mechanisms. MTT method was used to evaluate the viability of L1210 cells. Apoptosis of L1210 cells was detected by morphological assessment,
DNA electrophoresis assay and flow cytometry. Western blotting analysis was carried out to determine the apoptosis-related
proteins. Proliferation inhibition of L1210 cells by
alternol was found remarkably in a dose-dependent manner. When treated with
alternol, apoptotic morphological features of L1210 cells were observed by fluorescent microscopy (AO/EB) and the apoptosis rate was also elevated in a time-dependent manner.
After treatments with various concentrations of
alternol for 48
h, DNA laddering appeared. The increase of
reactive oxygen species (ROS) production was found after cells were exposed to
alternol for 6 h, while the decrease of mitochondrial transmembrane potential (delta psi m) was not found until cells were exposed to
alternol for 24 h. Furthermore, the level of Bcel-2 and Bcl-2/Bax was down-regulated, while the level of
caspase-3 and
caspase-9 but not
caspase-8 was up-regulated when
alternol was added for 72 h. In summary, the results suggested that
alternol could inhibit the proliferation of L1210 cells and induce apoptosis of L1210 cells, which was mediated by mitochondria-dependent pathway.