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.
