Cytotoxic drugs (or drugs which are poisonous to cells) were isolated from plants, and were first introduced into cancer chemotherapy in 1963. These anti-cancer drugs work on the principle that rapidly proliferating cells, such as neoplastic (or cancerous) ones, are most susceptible to damage by cytotoxic drugs.
Several variations include vinca alkaloids (vincristine and vinblastine) isolated from periwinkle plants and podaphylotoxin isolated from mayapple in 1970. Paclitaxel (Taxol) was isolated from the pacific yew in 1971, and developed to treat advanced breast cancer and lung cancer in the early 1990s.
Paclitaxel (Taxol) molecule