Author:
Bhattacharyya Sumit,Borthakur Alip,Tobacman Joanne K.
Abstract
AbstractProglucagon mRNA expression and GLP-1 secretion by cultured human L-cells (NCI-H716) were inhibited following exposure to λ-carrageenan, a commonly used additive in processed foods. Carrageenan is composed of sulfated or unsulfated galactose residues linked in alternating alpha-1,3 and beta-1,4 bonds and resembles the endogenous sulfated glycosaminoglycans. However, carrageenan has unusual alpha-1,3-galactosidic bonds, which are not innate to human cells and are implicated in immune responses. Exposure to carrageenan predictably causes inflammation, and carrageenan impairs glucose tolerance and contributes to insulin resistance. When cultured human L-cells were deprived overnight of glucose and serum and then exposed to high glucose, 10% FBS, and λ-carrageenan (1 µg/ml) for 10 minutes, 1 h, and 24 h, mRNA expression of proglucagon and secretion of GLP-1 were significantly reduced, compared to control cells not exposed to carrageenan. mRNA expression of proglucagon by mouse L-cells (STC-1) was also significantly reduced and supports the findings in the human cells. Exposure of co-cultured human intestinal epithelial cells (LS174T) to the spent media of the carrageenan-treated L-cells led to a decline in mRNA expression of GLUT-2 at 24 h. These findings suggest that ingestion of carrageenan-containing processed foods may impair the production of GLP-1, counteract the effect of GLP-1 receptor agonists and induce secondary effects on intestinal epithelial cells.
Funder
American Diabetes Association
Publisher
Springer Science and Business Media LLC
Reference19 articles.
1. Holst JJ. Discovery of the GI effects of GLP-1: an historical perspective. Dig Dis Sci. 2022;67:2716–20.
2. Reimer RA, Darimont C, Gremlich S, Nicolas-Métral V, Rüegg UT, Macé K. A human cellular model for studying the regulation of glucagon-like peptide-1 secretion. Endocrinology. 2001;142:4522–8.
3. Lu VB, Gribble FM, Reimann F. Nutrient-induced cellular mechanisms of gut hormone secretion. Nutrients. 2021;13:883–916.
4. Gagnon J, Brubaker PL. Chapter 20: NCI-H716 Cells. In: Verhoeckx K, Cotter P, López-Esposito I, et al. editors. The impact of food bioactives on health: In vitro and ex vivo models. (Internet). Cham (CH):Springer; 2015. https://www.ncbi.nlm.nih.gov/books/NBK500143/.
5. Tobacman JK. Review of harmful gastrointestinal effects of carrageenan in animal experiments. Environ Health Perspect. 2001;109:983–94.