Natural Products in Cancer Chemoprevention and Chemotherapy

Cancer is a very fatal, challenging and complex disease. A large number of people across the globe are suffering from various types of cancer. The bioactive substances isolated from different parts of several herbs and spices have shown their valuable preventive and therapeutic role against different forms of cancer. The recent technological innovations have made it possible to explore the molecular targets of these bioactive substances and also enabled us to know the mechanism of action related to disease modulation. Our traditional knowledge related to chemopreventive and chemotherapeutic role of herbs is now being validated and explored by the use of modern biological techniques. However, mechanism of action that governs anticancer effect has not been well elucidated for many herbs and natural products. Herbal extracts are the mixture of different active substances, therefore screening and pharmacological response of each individual compound should be validated separately to gain some insight about mechanism of anticancer property. Polyphenols play significant role in initiation, promotion and progression of cancers by modulating the enzymes and signal of diverse pathways related to cellular proliferations, differentiation, angiogenesis, apoptosis and metastasis. These natural bioactives also serve as lead compounds for drug designing and their biological activity can be further optimize by some desired chemical modification. Optimisation of the therapeutic inhibitors can be enhanced using systems biology modelling of the molecular pathways related to the disease. The aim of this chapter is to provide the insight into the molecular basis of preventive and therapeutic effect of natural bioactive substance against cancer diseases.

Keywords: Apoptosis, Cancer, Chemotherapy, Combination therapy, Metastasis, Natural products, Polyphenols Cell division, Telomerase, Topoisomerase, Transcription factor.