Methylation, Hydroxylation, Glycosylation and Acylation Affect the Transport of Wine Anthocyanins in Caco-2 Cells

Abstract

Anthocyanins are substances with multiple physiological activities widely present in red wine, but the influence of structure (methylation, hydroxylation, acylation, glycosylation) on the transport remains ill-defined. In the present study, Caco-2 monolayers were used as an in vitro model of the absorptive intestinal epithelium to transport different types of anthocyanin samples. Results showed that both methylation and acetylation promote the level of transport. Monoglycoside standard exhibited higher transport amount and rate compared to diglycoside standard while the transport level of the monoglycoside mixture was unexpectedly lower than that of the diglycoside mixture. Caco-2 monolayers appeared to be more capable of transporting the single standard than the mixed standard. Meanwhile, the transport of anthocyanins in Caco-2 cell model showed time- and concentration-dependent trends. Anthocyanin treatment had a greater effect on sodium-dependent glucose transporter 1 (SGLT1) mRNA expression than glucose transporter 2 (GLUT2), and significantly down-regulated the protein expression of SGLT1. Although the low bioavailability of anthocyanins requires much more research, further evidence of the role of structure is provided.

The Role of Anthocyanins in Alleviating Intestinal Diseases: A Mini Review

“…Both passive diffusion or active transporters (sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2)) transport anthocyanins and their degradation products through intestinal epithelial cells, with their absorption rate depending on their specific structure . Besides that, anthocyanins’ transport across the gastrointestinal barriers occurs in a time- and concentration-dependent manner . Rather than being absorbed in the upper small intestine, the majority of anthocyanins pass to the colon, , where they are metabolized into a variety of low-molecular-weight catabolites by bacteria from the intestinal microbiota, with the main metabolic processes including the cleavage of glycoside bonds, hydrogenation, methylation, hydroxylation, and decomposition. ,, A human intervention study (healthy + ileostomy probands) has confirmed that the colon is a vital organ for absorbing biologically active ingredients including anthocyanins as well as their degradation derivatives .…”

“…As an important subfamily of flavonoids, anthocyanins consist of a common tricyclic structure with two benzyl rings (A and B) and one heterocyclic ring (C) (Figure ) , and usually with 2 or 3 substituents, containing a sugar group and frequently an organic acid group , More than 1000 anthocyanins have been found in plants . Anthocyanins occur in nature as anthocyanidin glycosides, which are considered more stable than anthocyanidins .…”