The new treatment, called PEP005, is a topical gel containing a molecule called ingenol 3-angelate. It is derived from the milky sap of a common garden weed called the petty spurge or radium weed (scientifically, Euphorbia peplus), which has long been used as a traditional folk medicine in many countries for the treatment of skin conditions. It activates a molecule in the body called protein kinase C, which in turn helps control various cellular functions. The previous phase II trials showed promising results: after applying the gel for only two days, 71-75% of the lesions disappeared after two months. Side effects were no more serious than localized redness and peeling. PEP005 is also being studied for the treatment of basal cell carcinoma, bladder cancer, and even leukemia.
This is the proper way for natural products to enter the market: use "traditional" knowledge and "home remedies" for initial ideas, then isolate the specific chemical that is responsible for the effect, then thoroughly test it using double-blind clinical trials. You might be surprised to learn that the herbs, supplements and homeopathic remedies on your store shelves don't typically go through this process -- and for that reason, are usually no more effective than a placebo.
"Peplin Completes Enrollment for its First Phase III AK Clinical Trial." Peplin. 2 January 2009.