title: Sicilian pistachio (Pistacia vera L.) nut inhibits expression and release of inflammatory mediators and reverts the increase of paracellular permeability in IL-1β-exposed human intestinal epithelial cells.
abstract: BACKGROUND
  Dietary approaches to control inflammatory bowel diseases (IBD) may include proanthocyanidin-rich foods. Our previous research showed that a hydrophilic extract from Sicilian pistachio nut (HPE) contains substantial amounts of proanthocyanidins and possesses anti-inflammatory activities.
  
  
  OBJECTIVE
  We studied the effects of HPE and of its polymeric proanthocyanidin fraction (PPF) in a cell model that simulated some conditions of IBD, consisting of interleukin (IL)-1β-stimulated Caco-2 cells.
  
  
  METHODS
  HPE was prepared by Pistacia vera L. nuts, and PPF was isolated from HPE by adsorbance chromatography. Proanthocyanidins were quantified as anthocyanidins after acidic hydrolysis. Differentiated Caco-2 cells were pre-incubated with HPE or PPF and then were exposed to IL-1β. Cell viability and parameters associated with nuclear factor-κB (NF-κB) activation were assayed. Adsorption of polymeric proanthocyanidins to the cell membrane was investigated by transepithelial electrical resistance (TEER) measurements.
  
  
  RESULTS
  HPE decreased prostaglandin (PG)E2 production, IL-6 and IL-8 release, and cyclooxygenase (COX)-2 expression. HPE also inhibited the increase in paracellular permeability and reduced NF-κB activation. Polymeric proanthocyanidins, tested at a concentration comparable with their content in HPE, produced effects comparable to HPE. Finally, cell exposure to PPF increases TEER of the epithelial monolayers.
  
  
  CONCLUSIONS
  Our results provide evidence that pistachio nut components inhibit inflammatory response of intestinal epithelial cells in vitro and indicate polymeric proanthocyanidins as the major bioactive nut components. The protection implies inhibition of NF-κB activation and occurs in parallel with the adsorption of polymeric proanthocyanidins to cell membrane. Our findings suggest that intake of small amounts of pistachio nut can exert beneficial effects to gastrointestinal pathophysiology.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Via Michele Cipolla 74, 90123, Palermo, Italy, carla.gentile@unipa.it.
authors.forename: C
authors.initials: C
authors.lastname: Gentile
authors.forename: A
authors.initials: A
authors.lastname: Perrone
authors.forename: A
authors.initials: A
authors.lastname: Attanzio
authors.forename: L
authors.initials: L
authors.lastname: Tesoriere
authors.forename: M A
authors.initials: MA
authors.lastname: Livrea
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D018938:Caco-2 Cells; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology / Q000187:drug effects*; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009754:Nuts; D010539:Permeability; D027927:Pistacia; D044945:Proanthocyanidins / Q000494:pharmacology
chemical_list: D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D044945:Proanthocyanidins; C013221:proanthocyanidin; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human