Traditional medicine patents lead to enhanced drug discovery from natural products
Hippocrates, the father of modern medicine, noted that powder derived from the bark of a willow tree helped to relieve pain and headaches, and in the 1800s, chemists isolated the beneficial substance as salicylic acid and refined it by buffering sodium salicylate with acetyl chloride to create acetylsalicylic acid, or aspirin.
Nowadays, natural products are ripe for potential drug discovery and the life sciences sector is rich with traditional medicine patents. A growing reservoir of traditional medicine content is available, along with efficient and productive search methods for exploring it. John Zabilski explains.
Traditional medicine refers to the knowledge, skills and practices of maintaining health and treating physical and mental illness based on observations, beliefs and experiences indigenous to different cultures. In some Asian and African countries, traditional medicine is the primary means of healthcare for 80 percent of the population.
Traditional medicines and treatments are often employed as alternative or complementary therapies to modern medical treatments where they may have fewer side effects. Ginger, for example, is often recommended to safely relieve pregnancy-related nausea and vomiting. Traditional medicines may also provide effective alternatives for drug-resistant diseases. Drugs derived from traditional medicines have the added benefit of generally being less expensive to develop than synthetic drugs.
Because of their therapeutic promise, many natural products are being studied for multiple uses. For example, peony, sage and Ligusticum chuanxiong (Szechuan lovage) are being studied as analgesics, anti-inflammatories, antibacterials, anticarcinogens and hypertension medicines.
Botanicals used in traditional medicines are yielding successful drugs. In 2002, 1,141 different traditional plant drugs were registered for their therapeutic activities, including several new single compounds from plants such as arteannuin, an antimalarial extracted from sweet wormwood qinghao (Artemisia annua). The use of milk thistle (Silybum marianum) to treat liver ailments can be traced back to ancient Greece and Rome.
More recently, its active compound, silybin, has been studied in clinical trials as an antitumor agent. In one randomised clinical trial involving children with acute lymphoblastic leukemia, silybin was found to decrease the harmful effects of chemotherapy on the liver without diminishing the effects of cancer treatment.
Taxol (paclitaxel), a well-known chemotherapy drug, was discovered as part of a US Department of Agriculture programme to find natural chemicals that might be used as drugs. Found in the bark of the rare Pacific yew (Taxus brevifolia) tree, taxol was in such a high demand that its production threatened that species’ existence.
Fortunately, scientists were able to derive the active compound from the abundant European yew using semisynthetic production, which sustained paclitaxel’s availability for chemotherapy, as well as the Pacific yew’s existence.
Natural compounds have been part of the patenting tradition since the 1990s, steadily contributing to a significant body of work.
Traditional medicine content in CAS’s literature database
Traditional medicine patents and other relevant published literature constitute a unique form of prior art for intellectual property professionals in the life sciences sector. But until recently, traditional medicine information has been largely inaccessible for a number of reasons, such as a lack of available English-language translations.
Patent coverage
CAS databases use a variety of reputable scientific sources. Since 2001, more than 50,000 traditional medicine patents have been added to the CAS literature database. It may come as no surprise that Asia is the regional leader in these patents, with more than 90 percent reported. Among these, China represents 60 percent, Japan 20 percent and South Korea 10 percent. The remaining 10 percent comes from several countries, including the United States, France and Canada.
CAS casts a wide net to include 2,100 Asian serial journals and many Asian patent authorities, ensuring an excellent coverage of Asia. Chinese patent coverage in the CAS literature database includes multiple publication types and family information, and provides English translations of many ‘obscure’ Asian-language patent and journal articles.
