Which plant from Madagascar is used to produce the chemotherapy drug vincristine?

Catharanthus roseus is the Madagascar plant used to produce the chemotherapy drug vincristine.

Often called Madagascar periwinkle or rosy periwinkle, Catharanthus roseus is a flowering plant native to Madagascar and a member of the dogbane family, Apocynaceae. Its leaves and stems contain alkaloids that led to the development of vincristine and the related drug vinblastine.

The discovery was unexpected. In the 1950s, researchers investigating the plant as a possible treatment for diabetes found that its extracts could suppress bone-marrow activity. That observation redirected research toward cancer treatment, eventually leading to the isolation of the vinca alkaloids. Vincristine became especially important in treating childhood leukemia, lymphomas, and several other cancers.

A common mix-up is the name Vinca rosea, an older classification formerly used for this species. The plant is not the same as Vinca major or Vinca minor, which are different periwinkle species. Catharanthus roseus is also toxic and should not be used as a home remedy.