Mechanism of Action of Anticancer Herbal Medicines

Cancer is a main health challenge for the world due to unavailability of standard treatments and severe side effects of chemotherapy. It is the second major cause of casualty worldwide after cardiac disorder. Medicinal plants are used for the treatment of various diseases since ancient time. Due to toxicity of allopathic medicines, peoples are coming back toward the use of natural medicines for the treatment of diseases. Approximately 38% of Americans are using alternative medicine or herbal medicines and spend around $34 billion dollars yearly on it. Constituents isolated from plants showed a crucial role in the development of useful anticancer agent. These include etoposide, vincristine and vinblastine from Catharantus roseus, camptothecin from Camptotheca acuminata, podophyllotoxin from Podophyllum peltatum, etc. The aim of the chapter is to describe various anticancer plants and their possible mechanisms of action in the prevention of cancer.