Anti-inflammatory effects of phenolic-rich cranberry bean (Phaseolus vulgaris L.) extracts and enhanced cellular antioxidant enzyme activities in Caco-2 cells Peter X. Chen a,b , Hua Zhang a , Massimo F. Marcone b , Karl Peter Pauls c , Ronghua Liu a , Yao Tang d , Bing Zhang a,e , Justin B. Renaud f , Rong Tsao a,⇑ a Guelph Food Research Center, Agriculture and Agri-Food Canada, 93 Stone Road West, Guelph, Ontario N1G 5C9, Canada b Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, Ontario N1G 2W1, Canada c Department of Plant Agriculture, University of Guelph, Guelph, Ontario N1G 2W1, Canada d Center for Excellence in Post-Harvest Technologies, North Carolina A&T State University, Kannapolis, NC 28081, United States e State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China f London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3, Canada article info Article history: Received 7 November 2016 Received in revised form 8 December 2016 Accepted 16 December 2016 Available online xxxx Keywords: Dry beans Phaseolus vulgaris L. Phenolic acids Flavonoids Anthocyanins Proanthocyanidins Antioxidant Anti-inflammation HPLC-DAD LC-ESI-MS Caco-2 cells abstract Purified phenolic extracts of cooked regular-darkening (RR) and non-darkening (CND) cranberry beans were evaluated for their phenolic content, antioxidant and anti-inflammatory activity and bioavailability using a human colonic carcinoma (Caco-2) cell model. Major compounds included flavanols such as cat- echin, epicatechin and proanthocyanidins which were predominant to RR extract. RR and CND both con- tained p-coumaric acid, ferulic acid and tryptophan. Our results showed strong cellular antioxidant activity in RR and dose-dependent attenuation of TNF-a-induced pro-inflammatory cytokine Interleukin-8 (IL-8) secretion. In addition, the extracts displayed protective benefit to endogenous antiox- idant enzymes such as SOD, CAT, GPx and GR as well as GSH. Flavanols displayed poor bioavailability sug- gesting the beneficial effects occur via adsorption on the cell surface leading to cell signalling and localized radical scavenging activity. Our results support the beneficial effects of cranberry bean pheno- lics in their ability to ameliorate oxidative stress conditions notably in intestinal inflammatory responses. Crown Copyright Ó 2016 Published by Elsevier Ltd. All rights reserved. Contents 1. Introduction .......................................................................................................... 00 2. Materials and methods ................................................................................................. 00 2.1. Chemicals and reagents ........................................................................................... 00 2.2. Dry bean samples ................................................................................................ 00 2.3. Extraction and purification ......................................................................................... 00 2.4. Identification and quantification of phenolics .......................................................................... 00 2.4.1. HPLC-DAD analysis ........................................................................................ 00 2.5. Cell culture ..................................................................................................... 00 2.6. WST-1 cell viability assay .......................................................................................... 00 2.7. Cellular antioxidant activity (CAA) ................................................................................... 00 2.8. Interleukin-8 immunoassay ........................................................................................ 00 2.9. Determination of intracellular antioxidant enzyme activity............................................................... 00 http://dx.doi.org/10.1016/j.jff.2016.12.027 1756-4646/Crown Copyright Ó 2016 Published by Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: rong.cao@agr.gc.ca (R. Tsao). Journal of Functional Foods xxx (2017) xxx–xxx Contents lists available at ScienceDirect Journal of Functional Foods journal homepage: www.elsevier.com/locate/jff Please cite this article in press as: Chen, P. X., et al. Anti-inflammatory effects of phenolic-rich cranberry bean (Phaseolus vulgaris L.) extracts and enhanced cellular antioxidant enzyme activities in Caco-2 cells. Journal of Functional Foods (2017), http://dx.doi.org/10.1016/j.jff.2016.12.027