Coleus forskohlii is a perennial plant, with a strong, camphor-like odor. It is in the mint family. It grows well in warm temperate or subtropical areas. The plant is native to areas of India, Myanmar, Nepal, and Sri Lanka. Coleus has long been used in traditional Indian (Ayurvedic) medicine, but gained popularity when a chemical extract of the root called forskolin demonstrated properties that make it a potential treatment for asthma, bronchitis, glaucoma, congestive heart failure, and other conditions. Forskolin was first identified by Western researchers in the 1970s, but the effects of the whole coleus plant and its extracts have not been as well studied or understood.
Another species of coleus, Coleus kilimandschari, is found in parts of Africa and has been used in Rwandan folk medicine to treat infections and autoimmune diseases. Recent studies of Rwandan coleus indicate that it is effective against a variety of disorders involving destruction of red blood cells. As of 2002, however, Rwandan coleus has not been studied as intensively as Coleus forskohlii, and its extracts await further analysis.
Chinese research indicates that several diterpenoids found in the leaves and stems of coleus may be effective against leukemia cells. These recently discovered compounds, however, require further study and analysis.
Judith Turner, The Gale Group Inc., Gale, Detroit,