title: Antioxidant and anti-inflammatory activity of a flavonoid-rich concentrate recovered from Opuntia ficus-indica juice.
abstract: In this work, Opuntia ficus indica juice was explored as a potential source of natural antioxidant and anti-inflammatory ingredients towards intestinal inflammation. An adsorption separation process was used to produce a natural flavonoid-rich concentrate (FRC) from Opuntia ficus-indica juice. The FRC effect (co- or pre-incubation) on induced-oxidative stress and induced-inflammation was evaluated in human Caco-2 cells. The main constituents identified and present in the extract are flavonoids (namely isorhamnetins and their derivatives such as isorhamnetin 3-O-rhamnose-rutinoside and isorhamnetin 3-O-rutinoside) and phenolic acids (such as ferulic, piscidic and eucomic acids). Our results showed that co-incubation of FRC with the stress-inducer attenuates radicals production in a much more significant manner than pre-incubation. These results suggest that FRC compounds which cannot pass the cell membrane freely (isorhamnetin derivatives) have an ability to inhibit the formation of H2O2-induced radicals in the surrounding environment of intestinal epithelial cells. The capacity of FRC (co-incubation) for suppressing (at the extracellular level) free radicals chain initiation or propagation reaction was probably related with a more pronounced reduction in protein oxidation. A similar response was observed in the inflammatory state, where a marked decrease in IL-8 secretion and blocked degradation of IκBα was achieved for FRC co-incubation. Simultaneously, treatment with FRC significantly reduces NO and TNF-α expression and modulates apparent permeability in Caco-2 cells. In these cases, no significant differences were found between pre- and co-incubation treatments suggesting that bioavailable phenolics, such as ferulic, eucomic and piscidic acids and isorhamnetin, act at the intracellular environment.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República, Estação Agronómica Nacional, 2780-157 Oeiras, Portugal. amatias@itqb.unl.pt cduarte@itqb.unl.pt.
authors.forename: A
authors.initials: A
authors.lastname: Matias
authors.forename: S L
authors.initials: SL
authors.lastname: Nunes
authors.forename: J
authors.initials: J
authors.lastname: Poejo
authors.forename: E
authors.initials: E
authors.lastname: Mecha
authors.forename: A T
authors.initials: AT
authors.lastname: Serra
authors.forename: Paulo J Amorim
authors.initials: PJ
authors.lastname: Madeira
authors.forename: M R
authors.initials: MR
authors.lastname: Bronze
authors.forename: C M M
authors.initials: CM
authors.lastname: Duarte
mesh_terms: D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001628:Beverages / Q000032:analysis*; D018938:Caco-2 Cells; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology; D029747:Opuntia / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D005419:Flavonoids; D016209:Interleukin-8; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha