Levistolide A is a naturally occurring compound isolated from Ligusticum chuanxiong Hort, which is used in traditional Chinese medicine to treat cancer. Levistolide has been studied in vitro against cell models for colon cancer and breast cancer. It was effective at inducing ER programmed apoptosis in colon cancer cells. In a cell model for breast cancer, levistolide was shown to enhance the apoptotic effects of adriamycin and vincristine. The effect of levistomide is correlated with cleavage of poly(ADP-ribose) polymerase PARP and up-regulation of caspase-3.