White Catharanthus roseus
Catharanthus (Madagascar Periwinkle) is a genus of eight species of herbaceous perennial plants, seven endemic to the island of Madagascar, the eighth native to the Indian subcontinent in southern Asia.
- Catharanthus coriaceus Markgr. Madagascar.
- Catharanthus lanceus (Bojer ex A.DC.) Pichon. Madagascar.
- Catharanthus longifolius (Pichon) Pichon. Madagascar.
- Catharanthus ovalis Markgr. Madagascar.
- Catharanthus pusillus (Murray) G.Don. Indian subcontinent.
- Catharanthus roseus (L.) G.Don. Madagascar.
- Catharanthus scitulus (Pichon) Pichon. Madagascar.
- Catharanthus trichophyllus (Baker) Pichon. Madagascar.
Uses and cultivation
The species are self-propagating from seed; the seeds require a period of total darkness to germinate. Cuttings from mature plants will also root readily.
One species, C. roseus, has been widely cultivated and introduced, becoming an invasive species in some areas.
C. roseus has gained interest from the pharmaceutical industry; the alkaloids vincristine and vinblastine from its sap have been shown to be an effective treatment for leukaemia. Although the sap is poisonous if ingested, some 70 useful alkaloids have been identified from it. In Madagascar, extracts have been used for hundreds of years in herbal medicine for the treatment of diabetes, as hemostatics and tranquilizers, to lower blood pressure, and as disinfectants. The extracts are not without their side effects, however, which include hair loss.
Vinca alkaloids are anti-mitotic and anti-microtubule agents. They are nowadays produced synthetically and used as drugs in cancer therapy and as immunosuppressive drugs. These compounds are vinblastine, vincristine, vindesine and vinorelbine. Periwinkle extracts and derivatives, such as vinpocetine, are also used as nootropic drugs.