Bioavailable Citrus sinensis Extract: Polyphenolic Composition and Biological Activity
Department of Pharmacy, School of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Italy
Department of Agriculture, Laboratory of Food Chemistry, University of Reggio Calabria, Via Melissari stecca n°4, I-89122 Reggio Calabria, Italy
Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, I-80131 Napoli, Italy
Department of Science, University of Basilicata, Viale dell’Ateneo Lucano 10, I-85100 Potenza, Italy
National Institute of Gastroenterology “S. de Bellis”, Institute of Research, I-70013 Castellana Grotte, Italy
European Biomedical Research Institute of Salerno, Via De Renzi 3, I-84125 Salerno, Italy
Author to whom correspondence should be addressed.
Academic Editor: Derek J. McPhee
Molecules 2017, 22(4), 623; https://doi.org/10.3390/molecules22040623
Received: 7 March 2017 / Revised: 4 April 2017 / Accepted: 9 April 2017 / Published: 15 April 2017
(This article belongs to the Section Natural Products Chemistry)
Citrus plants contain large amounts of flavonoids with beneficial effects on human health. In the present study, the antioxidant and anti-inflammatory potential of bioavailable polyphenols from Citrus sinensis was evaluated in vitro and ex vivo, using the murine macrophages cell line J774A.1 and primary peritoneal macrophages. Following simulated gastro-intestinal digestion, the in vitro bioavailability of Citrus sinensis polyphenolic extract was assessed using the human cell line Caco-2 grown as monolayers on a transwell membrane. Data demonstrated a relative permeation of its compounds (8.3%). Thus, the antioxidant and anti-inflammatory effect of polyphenolic Citrus sinensis fraction (Cs) was compared to the bioavailable one (CsB). Results revealed that Citrus extract were able to reduce macrophages pro-inflammatory mediators, including nitric oxide, iNOS, COX-2 and different cytokines. Moreover, the effect of Citrus sinensis polyphenols was associated with antioxidant effects, such as a reduction of reactive oxygen species (ROS) and heme-oxygenase-1 (HO-1) increased expression. Our results provide evidence that the bioavailable polyphenolic constituents of the Citrus sinensis extract accumulate prevalently at intestinal level and could reach systemic circulation exerting their effect. The bioavailable fraction showed a higher anti-inflammatory and antioxidant potential compared to the initial extract, thus highlighting its potential nutraceutical value.