Dissolution kinetics of polyphenol bearing calcium pectate hydrogels in simulated gastric or intestinal media and their anti-carcinogenic capacities

Abstract

Cherry laurel is an underutilized agricultural resource with a significant content of polyphenolic compounds that potentially may demonstrate antioxidant and anti-carcinogenic activities. In this study, the preparation of calcium pectate gels bearing cherry laurel polyphenols was aimed and their dissolution behaviors in simulated gastric and intestinal media were tested. In addition, the released fractions were collected and tested in cell culture media in order to determine the anti-proliferative characteristics. Cherry laurel polyphenol extracts were mixed with pectin dispersions (1:1) and calcium pectate gels were prepared by the extrusion dripping method. The freeze dried gel samples were analyzed for morphological characteristics (SEM) and dissolution kinetics in simulated gastrointestinal media. The rate of release in gastric medium was substantial (>= 94.9%) in all cases and dissolved fractions demonstrated significant anti-proliferative activity (approx. 85% inhibition for 55K06 and 611(04 extracts) against MCT 116 colon carcinoma cells even after 20x dilution. The findings were discussed with emphasis on their relevance to pectin-polyphenol interactions in dissolution behavior of the gels in simulated gastrointestinal media, and also to the preparation of functional lyophilizates that can be utilized in functional foods and pharmaceuticals. (C) 2017 Elsevier Ltd. All rights reserved.