Natural Agents Used in Chemoprevention of Aerodigestive and GI Cancers

Aerodigestive cancers are on an increasing level in both occurrence and mortality. A major cause in many of these cancers is disruption of the inflammatory pathway, leading to increased cell proliferation and epigenetic silencing of normal regulatory genes. Here, we review the research on several natural products: silibinin, silymarin, quercetin, neem and nimbolide, gingerol, epigallatecatechin-3- gallate, curcumin, genistein, and resveratrol conducted on aerodigestive cancers. These types of cancers are primarily those from oral cavity, esophagus/windpipe, stomach, small and large intestine, colon/rectum, and bile/pancreas tissues. We report on the utilization in vivo and in vitro systems to research these dose effects on the inflammatory and epigenetic pathway components within the aerodigestive cancer. To follow up on the basic research, we will discuss the remaining research questions and future directions involving these natural products as putative stand alone or in combination with clinical agents.