Natural products and drug discovery

The medicinal use of natural products—compounds that are derived from natural sources such as plants, animals or micro-organisms—precedes recorded human history probably by thousands of years. Palaeoanthropological studies at the cave site of Shanidar, located in the Zagros Mountains of Kurdistan in Iraq, have suggested that more than 60,000 years ago, Neanderthals might have been aware of the medicinal properties of various plants, as evidenced by pollen deposits in one of the graves at the site (Solecki, 1975). Over the ensuing millennia, humankind discovered and made use of an enormous range of natural compounds; the latest version of the Dictionary of Natural Products (DNP; http://dnp.chemnetbase.com) has just over 214,000 entries. Throughout our evolution, the importance of natural products for medicine and health has been enormous. Since our earliest ancestors chewed on certain herbs to relieve pain, or wrapped leaves around wounds to improve healing, natural products have often been the sole means to treat diseases and injuries. In fact, it has only been during the past decades that natural products have taken a secondary role in drug discovery and drug development, after the advent of molecular biology and combinatorial chemistry made possible the rational design of chemical compounds to target specific molecules. The past few years, however, have seen a renewed interest in the use of natural compounds and, more importantly, their role as a basis for drug development. The modern tools of chemistry and biology—in particular, the various ‘-omics’ technologies—now allow scientists to detail the exact nature of the biological effects of natural compounds on the human body, as well as to uncover possible synergies, which holds much promise for the development of new therapies against many devastating diseases, including dementia and cancer.