## 4 Role of Triterpenoids in Cancer Prevention  
### Role of Triterpenoids in Inflammation  
Inflammation is derived from the Latin word '_inflammare_ or _inflammatio_', which means, \"to set on fire.\" Inflammation is a basic defense mechanism in which the body reacts against infections, irritations, or other injuries. The four key features of inflammation are redness, heat, swelling, and pain. Inflammation stimulates the immune response at the site of injury or infection and is itself stimulated by increases in blood supply and vascular permeability, which allow more infiltration of plasma and leukocytes from the blood into injured tissues. This particular type of immune response is important because it helps the body to ward off pathogens and also to initiate the healing process in the damaged tissues. This reaction is classified as acute inflammation. Studies have shown that chronic inflammation is a progenitor of tumor progression and that many cancers have been found to arise from sites of infection, chronic irritation, and inflammation. Inflammation orchestrates the microenvironment around tumors and allows them to progress by fostering proliferation, survival, and migration [149]. The inflammatory cells and the network of signaling molecules provided by the inflammatory microenvironment are necessary for the malignant progression of transformed cells. Inflammation promotes tumor development through both nonimmune and immune. NF-\(\kappa\)B is a central transcription factor mediating inflammatory and innate immune responses. NF-\(\kappa\)B may be activated by various factors, including cytokines, microbial pathogens, and oxidative, genotoxic, physiological, or chemical stress factors. In addition to these, proinflammatory cytokines and chronic infections can play an important role in the stimulation of IKK activity, which leads to constitutive NF-\(\kappa\)B activation [150; 151; 152]. The activation of NF-\(\kappa\)B through IKK\(\beta\) plays a major role in inflammation induced tumor promotion and progression. Various proinflammatory factors like TNF\(\alpha\) and Toll-like receptor ligands such as lipopolysaccharideacharide (LPS) normally activate these pathways [153]. This activation signals the transcription of various cancer-promoting genes such as antiapoptotic genes, proangiogenic genes, and proinvasion genes [154]. NF-\(\kappa\)B DNA binding is thought to result in the activation of a number of genes that lead to inflammatory diseases like Alzheimer disease and arthritis in addition to cancer [143]. Along with NF-kB, factors such as TNF and interleukins (IL-1\(\beta\), IL-6, and IL-8) also serve as connecting links between inflammation and cancer. TNF is released mainly from macrophages and regulates immune cells. Its dysregulation and overproduction lead to cancer and other diseases. TNF also plays a role in the activation of NF-kB by binding to a TNF receptor present on the cell surface that in turn triggers a pathway that leads to the activation of IKK [3]. Interleukins are a group of cytokines released in the body from numerous cells in response to various stimuli. While IL-1\(\beta\) plays an important role in the inflammatory response against infection by increasing the expression of endothelial adhesion factors, thus allowing infiltration of leukocytes at the site of infection, IL-6 is a proinflammatory cytokine released in response to trauma or tissue damage. IL-8, a member of the CXC chemokine family also known as CXCL8, can function as a mitogenic, angiogenic, and mutagenic factor promoting cancer progression [155]. Inflammatory cells and their regulators are found to facilitate angiogenesis and promote the growth, invasion, and metastasis of tumor cells [156]. Normal levels of some enzymes like inducible nitric oxide synthase (iNOS) and COX-2 play an essential role in the physiological protective response to tissue injury, but if expressed in excessive amounts, these inflammatory enzymes may cause carcinogenesis [149,157,158]. In tumor tissue, levels of prostaglandam (PGs) are often elevated.