(NaturalNews) Botanic Gardens Conservation International has warned that 400 medicinal plants around the world are at risk of extinction if current over-harvesting and deforestation practices continue.The organization, which has member gardens in 120 different countries, surveyed more than 600 members and university experts to compile a list of threatened medicinal plants.Among the most threatened are magnolias, with half of the world's species at risk due to deforestation. Magnolia has a 5,000-year history as a traditional Chinese medicine for cancer, dementia and heart disease.Also at risk is the yew tree, source of the popular cancer drug paclitaxel, which is synthesized from the tree's bark. But the bark from six trees must be used to create a single dose, placing the yew at risk of over-harvesting. The medicinal properties of hoodia, a Namibian native, have also placed it at risk of over-harvest, with large quantities being "ripped from the wild," according to the report. Because the plant suppresses appetite, drug companies in search of miracle weight-loss medications are harvesting more than the species can bear.In contrast, autumn crocus is being over-harvested mostly due to its ornamental appeal. But the plant is also a highly effective treatment for gout, and is being investigated for its leukemia-fighting abilities.More than 50 percent of prescription drugs use chemicals originally derived from plants.Even though many of the medicinal chemicals found in the 400 threatened plants can be synthesized in the laboratory, that does not mean the original plants no longer have medical benefit, the report emphasized. The vast majority of the five billion people on Earth still rely on traditional, plant-based medicine as their primary form of medical care."It is not an overstatement to say that if the precipitous decline of these species is not halted, it could destabilize the future of global healthcare," said report author Belinda Hawkins.