AbstractsBiology & Animal Science

Transport and Uptake of Anthocyanins in Gastric Tissue and Their Effect on the Gastric Inflammatory Response: Developing an in vitro Model Using the NCI-N87 Gastric Cell Line

by Allison A. Atnip




Institution: The Ohio State University
Department: Food Science and Technology
Degree: PhD
Year: 2014
Keywords: Food Science; Anthocyanins, Gastric cell line, Chokeberry, Stomach uptake, In vitro model
Record ID: 2042974
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=osu1417728159


Abstract

Anthocyanins are polyphenolic pigment compounds that are ubiquitous in the plant kingdom, imparting color to many fruits commonly consumed by humans. Anthocyanins have been researched for their many potential health benefits, including antioxidant, anti-inflammatory, anti-cancer, and cardioprotective activities. In order to maximize the benefits of anthocyanin intake for health (including for the development of functional foods), the uptake, metabolism, and bioavailability of anthocyanins throughout the gastrointestinal tract must be elucidated. Animal and human studies have shown that anthocyanin glycosides appear in plasma very rapidly after oral ingestion, suggesting a possible role of the stomach on the in vivo fate of anthocyanins. The effects of the gastric environment and chemical structure on the transport and uptake of anthocyanins in the stomach have not been well characterized. Cell culture models can be useful tools for investigating these behaviors; however the environment must be kept at physiological pH (7.4), not ideal for the study of the acidic environment of the stomach. The NCI-N87 cell line is an acid-stable model of the gastric epithelium, and has successfully been used to study drug metabolism in the stomach. We investigated the NCI-N87 cell line, seeded on 0.4 µm pore inserts, as a model to study the uptake and metabolism of anthocyanins in the stomach. The NCI-N87 cell line formed a coherent monolayer that was stable over a period of 18-32 days post-confluence. The pH levels of apical chambers were adjusted to pH 3.0, 5.0, or 7.4, with a basolateral pH of 7.4, with minimal effects on monolayer integrity. A slight initial drop in monolayer integrity at pH 3.0 was quickly recovered by 120 min treatment at 37°C. The mucus layer generated by the cells trapped a small amount of anthocyanins, but was easily removed by washing and did not appear to have significant effects on the analysis of cellular uptake. Transport and uptake of anthocyanins from chokeberry extract by NCI-N87 cells was dependent on treatment time, initial anthocyanin concentration, and apical pH. Overall anthocyanin recovery was significantly higher at apical pH 3.0 as compared with pH 5.0 and 7.4. As expected, over time and with increasing initial concentrations, the basolateral concentration of anthocyanins increased. The rate of anthocyanin transport increased over time, suggesting that the transport was not by passive diffusion alone. Generally, an apical pH of 3.0 showed the highest amount of transport, and pH 5.0 showed the lowest amount. There was also an observed effect of anthocyanin structure on transport, both for anthocyanins from chokeberry (significantly higher transport of cy-3-arabinoside and lower transport of cy-3-galactoside) and from red grape (higher transport of cyanidin-3-glu and lower transport of malvidin-3-glu). Finally, anthocyanins from chokeberry were shown to significantly inhibit increased IL-8 production in response to the IL-1ß induced inflammation of NCI-N87 cells. This suggests a potential…