Euphorbia fischeriana Steud.is a toxic perennial herb and has been shown to possess both toxic and therapeutic effects.Its root was known as Langdu and embodied in the Pharmacopoeia of The Peoples Republic China as a toxic traditional Chinese medicine.Jolkinolide B, a typical entabietane-type diterpenoid, isolated from the root of Euphorbia fischeriana Steud.It has been recognized as a major toxicity compound with suspected cytotoxic, inflammatory, and carcinogenic properties.Many adverse drug reactions are caused by the cytochrome P450 (CYP) dependent activation of drugs into reactive metabolites.However, there was limited information available in regard to its metabolism and cytotoxicity.