ABSTRACT
Plant-derived avonoids and related phenolic compounds are among the most abundant phytochemicals in the human diet. There is a substantial body of evidence that these compounds, in particular (−)-epicatechin, procyanidins, and related avan3-ols, can have benecial effects on health. This was initially attributed to their antioxidant activity. However, more recent research has shown that they regulate cell signaling pathways through highly specic mechanisms that sometimes, but not always, involve an antioxidant action. This chapter will discuss current evidence on the capacity of the avan-3-ols to modulate select signaling pathways through redox-dependent and -independent mechanisms. The mechanisms involve free radical scavenging actions, interactions with proteins that generate oxidants, interactions
12.1 Introduction ................................................................................................ 281 12.2 Chemical Structure, Bioavailability, and Metabolism of Flavan-3-ols
and Procyanidins ........................................................................................ 282 12.3 Flavan-3-ols and Procyanidins in the Regulation of Cell Signaling .......... 283
12.3.1 Antioxidant and Redox Regulation by Flavan-3-ols and Procyanidins ................................................................................. 283
12.3.2 Modulation of NF-κB by Flavan-3-ols and Procyanidins ............ 285 12.3.3 Modulation of Protein Kinases and Phosphatases by
Flavan-3-ols and Procyanidins .....................................................287 12.3.4 Modulation of Nfr2 and Other Signaling Pathways by
Flavan-3-ols and Procyanidins .....................................................288 12.4 Conclusions ................................................................................................. 289 Acknowledgments .................................................................................................. 289 Abbreviations ......................................................................................................... 289 References .............................................................................................................. 289
with signaling proteins, and interactions with membrane domains that concentrate signaling molecules. These effects could, in part, explain the health benets associated with a high consumption of fruit and vegetables.
