Modulation of Tumor Immunity by Medicinal Plant or Functional Food-Derived Compounds

Most forms of conventional cancer treatments are accompanied by undesirable side effects. Moreover, due to tumor heterogeneity, resistance to treatment and subsequent recurrence is often inevitable. Therefore, there is a need for development of progressive forms of adjuvant therapeutics. The tumor micro-environment is composed of tumor cells and multiple stromal cell types, including immune cells, many of which can produce pro-tumor chemokines and cytokines. The production of these molecules can result in a cascade effect, signaling other cells to promote an anti-cytotoxic, pro-tumor inflammatory response which hinders the necessary immune response needed to eliminate neoplastic cells. The pro-tumor inflammatory response is a key component during the progressive development of cancer. The “hijacking” of the immune system in the tumor environment provides a target which can be used to revert the immune system back to a type 1, pro-cytotoxic response. Natural compounds found in many traditional foods and medicines have a proven history of being anti-inflammatory, a key component which can be utilized during cancer treatment. Application of specific natural compounds in conjunction with conventional medicine can provide an additional level of support via modulation of the immune system. Phytochemicals found in turmeric, soy, and Scutellaria have shown profound effects on attenuating and modulating inflammation. This chapter looks into the mechanism of action and prospects for using these phytochemicals as an immune-modulatory adjuvant in the treatment of cancer.