Bisabololoxide A induces apoptosis in rat thymocytes.

In present study, the cytotoxic effect of micromolar BSBO was cytometrically examined on rat thymocytes by using appropriate fluorescent dyes. When the cells were incubated with BSBO for 24 h, BSBO at concentrations of 30 microM or more significantly increased populations of dead cells, shrunken cells, and cells with phosphatidylserine exposed on membrane surface. Both cell shrinkage and externalization of membrane phosphatidylserine are general features in an early stage of apoptosis. In addition, BSBO significantly increased population of cells containing hypodiploid DNA, and the increase was completely attenuated by Z-VAD-FMK, a pan-inhibitor for caspases, indicating an involvement of caspase activation[1]