Author(s): Nunes, Sara Alexandra Luis
Date: 2011
Persistent ID: http://hdl.handle.net/10362/6237
Origin: Repositório Institucional da UNL
Subject(s): Inflammatory bowel diseases; Polyphenols; Antioxidant activity; Anti-inflammatory activity; Caco-2 cells; Opuntia ficus-indica
Dissertation to obtain a Master Degree in Biotechnology
Inflammatory Bowel Diseases, namely Ulcerative colitis and Crohn’s disease, are chronic intestinal inflammatory disorders characterized by an excessive release of pro-inflammatory mediators, intestinal barrier dysfunction and altered permeability and excessive activation of NF-κB cascade that can lead to development of colon cancer. IBD conventional therapy involves multiple medications and long-term up to life-long treatments. Furthermore, these therapies are insufficiently selective and associated to severe side effects. Phenolic compounds are considered to possess antioxidant and anti-inflammatory activities and are a great hope in prevention and treatment of chronic intestinal inflammation. The aim of this study was to evaluate the preventive and prophylactic effects of Opuntia ficus-indica (cactus pear) and Prunus avium (cherry) polyphenolic-rich extract (PRE) in an in vitro cellmodel of Inflammatory Bowel Diseases. The phenolic composition of each PRE is completely different: for cherry’s PRE the main compounds founded were anthocyanins while in cactus pear’s PRE were isorhamnetin and its glycoside derivates and also a betaxantin. Cactus pear’s and cherry’s extract showed similar antioxidant activity in ORAC assay but cherry’s PRE has shown to be better in preventing radical formation by metal chelation (HORAC assay) and in inhibiting AAPH-induced LDL-oxidation. Cherry’s PRE exert a most significant protection against intracellular ROS formation, glutathione and protein oxidation than cactus pear’s PRE. Both extracts showed to be effective in reducing inflammatory mediators secretion (IL-8 and NO), attenuating barrier dysfunction and reducing NF-κB pathway activation. However, cherry’s PRE were more efficient in both perspectives studied. Both PREs didn’t affect the IL-10 secretion. Anti-inflammatory activity of 5-aminosalicylic acid, a common drug used in IBD therapy, was compared with cherry’s PRE. Both agents could modulate barrier dysfunction and permeability alteration and could, also, decrease IL-8 and NO secretion. Moreover, 5-ASA could increase IL-10 secretion. Obtained results suggest that cherry’s PRE could be use as co-therapeutic agent in IBD patients.
