Cancer chemoprevention through the induction of apoptosis by natural compounds

Abstract

As cell and tissue homeostasis are mediated by the balance between proliferation and apoptosis, controlling this balance is important for cancer chemoprevention. Cancer chemoprevention can be achieved by the use of natural, synthetic or biologic compounds that reverse, suppress or prevent the development of epithelial malignan-cies. Natural compounds including flavonoids are able to reduce oxidative stress, which is the most likely mechanism mediating the protective effects against cancer development. In addition, in vitro and in vivo studies have suggested that flavonoids, such as (-)-epigallocatechin-3-gallete (EGCG), quercetin, and curcumin, act by induc-tion of apoptosis. Several natural compounds inhibit cell proliferation and angiogenesis. Cer-tain natural products have been shown to inhibit the activation of nuclear factor kappa B (NF-κB) and Akt signaling pathways, both of which are known to maintain a homeostatic balance be-tween cell survival and apoptosis. Understanding the mechanism of these natural products will con-tribute to the development of more specific pre-ventive strategies against cancer development. Here we focus on the ability of natural cancer che-mopreventive agents to induce apoptosis, and at-tempt to provide evidence for the preventive and therapeutic effects of natural compounds, EGCG, quercetin, and curcumin, in a succinct manner highlightingκand Akt signaling pathways in vivo.