Fig. 1.

Sensitization of cells to tumour necrosis factor (TNF)-α-induced apoptosis by cordycepin. (a) Normal rat kidney epithelial (NRK-52E) cells were treated with 5 µg/ml cordycepin in the absence or presence of 10 ng/ml TNF-α for 48 h and subjected to phase-contrast microscopy. (b) The percentages of dead cells against total cells were evaluated by trypan blue analysis. Assays were performed in quadruplicate, and data are presented as means ± standard error. *Statistically significant difference (P < 0·05); NS, not statistically significant. (c) Cells were treated with indicated agents for 48 h and subjected to Western blot analysis of caspase-3. The level of β-actin is shown at the bottom as a loading control.