Author(s): Sheeja K

Abstract: Cancer usually initiated as a result of the stepwise accumulation of genetic and epigenetic changes in the cell. The role of the host immune system is very critical in the progression of cancer. It is an integrated system consists of different types of organs, cells and their products. Cancer cells grow and spread by avoiding detection and destruction by the immune system. A large number of evidences indicate that tumor microenvironment play crucial role in the subsequent conversion of primary tumor into more advanced malignancies. Tumor microenvironment is occupied with the cells of immune system such as macrophages, dendritic cells, NK cells and T cells with altered functions. It is well documented that modulation of immune system helps to eliminate cancer. Plant based remedies have always been used as an integral part of traditional medicines for modulating the immune system for different types aliments including cancer throughout the world. A better understanding of the cellular constituents of tumors microenvironment and their regulation may help to develop novel therapeutic approach in cancer therapy. In this review we summaries role of innate immune system in cancer, cells in tumor microenvironments and their interaction with tumor cells and natural products in cancer therapeutics.