Anticancer Natural Coumarins as Lead Compounds for the Discovery of New Drugs

Cancer is one of the most serious illnesses of our civilization. The International Agency for Research on Cancer estimated that 14.1 million new cancer cases have been diagnosed last year. Therefore, the cure efficiency of cancer chemotherapy depends not only on how the anticancer drug is delivered to its targets but also on the anticancer drug itself. Among the approved drugs, 80% are derived from natural compounds. In this sense, coumarins, natural polyphenols for which anticancer activity has been proved, can be a source or inspire the synthesis of new anticancer agents. Several natural coumarins, such as scopoletin, daphnetin, esculetin and the less known wedelolactone and galbanic acid, appear to have promising anticancer activities. This paper will provide a comprehensive overview of the advances on natural coumarins with potential therapeutic applications as anticancer agents highlighting the ones for which the mechanism of action is well defined and can serve as lead compounds for the design of new more potent molecules.