Targeting Apoptosis with Dietary Bioactive Agents

Abstract

Apoptosls, a form of programmed cell death, Is a pivotal defense against the occurrence of cancer and is essential to metazoans In maintaining tissue homeostasis. Apoptosls exhibits a distinctive phenotype and Involves elimination of potentially deleterious cells. Many diseases have been associated with aberrantly regulated apoptotlc cell death, ultimately leading to Inhibition of apoptosls and propagation of diseases such as cancer. Elucidation of the critical events associated with carcinogenesis provides the opportunity for dietary Intervention to prevent cancer development through Induction of apoptosls, particularly by bloactive agents or functional foods. Diet Is a significant environmental factor In the overall cancer process and can exacerbate or Interfere with carcinogenesis. Apoptosls occurs primarily through two well-recognized pathways In cells, Inciudlng the Intrinsic, or mitochondrial-mediated, effector mechanism and the extrinsic, or death receptor-mediated, effector mechanism. In addition to diet's effects on protein expression and function, evidence Is also accumulating that a large number of dietary food components can exert effects on the human genome, either directly or Indirectly, to modUlate gene expression. In fact, many diet-related genes are Involved In carcinogenesis as well as apoptosls, and thus are ultimately molecular targets for dietary chemopreventlon. There are multiple steps within pathways In which dietary components can alter gene expression and phenotypes of cells and thus Influence cancer outcomes (nutritional transcrlptomlc effect). Thus, apoptosls Is an emerging therapeutic target of bloactlve agents of diet. In this review, the process of apoptosls Is discussed and the potential mechanistic Interaction of bloactlve agents, as

Induction of G1 arrest and apoptosis by Scutellaria barbata in the human promyelocytic leukemia HL-60 cell line

“…The search for promising agents that could reduce the incidence and the burden of cancer has become increasingly important in recent years. Naturally occurring dietary supplements and herbs have stimulated great interest because of their chemopreventive and chemotherapeutic properties as well as their relatively non-toxic effects, low cost and availability as oral formulations (41)(42)(43)(44). Scutellaria barbata used in Chinese medicine has been shown to provide protection against several major liver, lung, and rectal cancers (17,45).…”

Fructus Xanthii extract protects against cytokine-induced damage in pancreatic β-cells through suppression of NF-κB activation

“…Traditional plant medicines have been used for centuries in different regions of the world. Despite insufficient evidence to support its therapeutic efficacy, the use of herbal medicine has increased considerably due to the relatively non-toxic effects, low cost and availability of these treatments (35,36). Fructus Xanthii, which is commonly used in Chinese medicine, was reported to have inhibitory effects on mast cell-mediated allergic reaction (37), as well as anti-inflammatory actions in lipopolysaccharide-stimulated inflammatory responses (38).…”

Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

“…Most importantly, a growing body of evidence demonstrates that current cancer therapies, such as chemo-, radio-, immuno-or suicide gene-therapy, primarily exert their antitumor effect by triggering apoptosis in cancer cells (Fulda and Debatin, 2004). However, cancer cells use multiple pathways to evade apoptosis, which underlie the insufficiency of current therapies (Khan et al, 2006;Martin, 2006). Therefore, searching for bioactive agents with the ability to induce apoptosis in cancer cells is a promising option for cancer chemoprevention and/or chemotherapy.…”

“…Though the presence of huge amounts of saponin compounds in N. sativa has been reported, any study regarding their anti-cancer activity has not been reported yet.Based on the abovementioned studies and considering the fact that in some cases herbal extracts are showing more potency than the purified components (Seeram et al, 2004;2006), this study was undertaken. We investigated the anti-proliferative potentiality of the crude saponin extract of N. sativa on human colon cancer cells, HCT116, and further elaborated the molecular mechanism underlying this action.…”