Extract from the leaves of Toona sinensis roemor exerts potent antiproliferative effect on human lung cancer cells.

Recent study indicated that the components of Toona sinensis Roemor have potent anti-inflammatory and analgesic effects. These components have also been reported to inhibit the growth of boils in vivo. In this study, we investigated the effect of crude extract from the leaves of Toona sinensis Roemor on the proliferation of A549 lung cancer cells. We found that the extract effectively blocked cell cycle progression by inhibiting the expression of cyclin D1 and E in A549 cells. Additionally, incubation of the extract led to activation of caspase-3-like proteases and apoptotic cell death. Conversely, the extract did not show any significant cytotoxic effect on primarily cultured human foreskin fibroblasts or MRC-5 human lung fibroblasts. Therefore, antiproliferative action of the extract is specific for tumor cells. Our results suggest that the components of Toona sinensis Roemor have potent anticancer effects in vitro and identification of the useful components in the extract may lead to the development of a novel class of anticancer drugs.