title: Polyphenol compounds and PKC signaling.
abstract: Naturally occurring polyphenols found in food sources provide huge health benefits. Several polyphenolic compounds are implicated in the prevention of disease states, such as cancer. One of the mechanisms by which polyphenols exert their biological actions is by interfering in the protein kinase C (PKC) signaling pathways. PKC belongs to a superfamily of serine-threonine kinase and are primarily involved in phosphorylation of target proteins controlling activation and inhibition of many cellular processes directly or indirectly.
  
  
  
  Despite the availability of substantial literature data on polyphenols' regulation of PKC, no comprehensive review article is currently available on this subject. This article reviews PKC-polyphenol interactions and its relevance to various disease states. In particular, salient features of polyphenols, PKC, interactions of naturally occurring polyphenols with PKC, and future perspective of research on this subject are discussed.
  
  
  
  Some polyphenols exert their antioxidant properties by regulating the transcription of the antioxidant enzyme genes through PKC signaling. Regulation of PKC by polyphenols is isoform dependent. The activation or inhibition of PKC by polyphenols has been found to be dependent on the presence of membrane, Ca(2+) ion, cofactors, cell and tissue types etc. Two polyphenols, curcumin and resveratrol are in clinical trials for the treatment of colon cancer.
  
  
  
  The fact that 74% of the cancer drugs are derived from natural sources, naturally occurring polyphenols or its simple analogs with improved bioavailability may have the potential to be cancer drugs in the future.
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States. Electronic address: jdas@uh.edu.
authors.forename: Joydip
authors.initials: J
authors.lastname: Das
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Ramani
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
authors.forename: M Olufemi
authors.initials: MO
authors.lastname: Suraju
mesh_terms: D003474:Curcumin / Q000627:therapeutic use; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D059808:Polyphenols / Q000627:therapeutic use*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000077185:Resveratrol; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000627:therapeutic use
chemical_list: D059808:Polyphenols; D013267:Stilbenes; D011493:Protein Kinase C; D003474:Curcumin; D000077185:Resveratrol
keywords: Antioxidant; Cancer; Polyphenol; Protein kinase C; Signal transduction