Efficient transport and biotransformation of dipeptide-like tyrosine/phenylalanine-conjugated phenolic amide esters in THP-1 cells and PBMCs: A potential means for transporting compounds inside monocytes/macrophages

Background: Recent studies suggest that dipeptide-like tyrosine/phenylalanine-conjugated phenolic amide compounds may contain several biological activities including anti-inflammatory activity. However, there is currently no information about their transport and biotransformation in monocytes/macrophages involved in inflammation process. Objective: The objective of this study was to investigate cell transport and biotransformation of the phenolic amides and esters in monocyte/macrophage-like cells. Methods: Cell transport and biotransformation of the phenolic amides and esters (N-coumaroylphenylalanine, N-caffeoylphenylalanine, N-feruloylphenylalanine, N-coumaroyltyrosine, N-caffeoyltyrosine, N-feruloyltyrosine and their O-methyl esters) were investigated in THP-1 cells and PBMCs using HPLC, cellular and kinetics methods Results: In THP-1 cells, the phenolic amides were not transported significantly, but their O-methyl esters were transported significantly (P < 0.02). Also, the transport of the esters was found to be sodium-independent and pH-dependent. Among the tested esters, N-feruloylphenylalanine-O-methyl ester showed the highest uptake (Km of 25 µM), and the uptake was inhibited by PepT1/2 substrate and blocker (GlySar and enalapril) in THP-1 cells. Particularly, enalapril competitively inhibited the uptake with Ki of 560 µM. The data also showed that N-feruloylphenylalanine-O-methyl ester and N-feruloyltyrosine-O-methyl ester could be biotransformed into parent phenolic amides in THP-1 cells. Similarly, the ester compounds were also found to be transported and biotransformed in PBMCs. Conclusion: The data suggest that dipeptide-like tyrosine/phenylalanine-conjugated phenolic amide esters may be transported and biotransformed in THP-1 cells and PBMCs.

PAN – EUROPEAN TRANSPORT CORRIDORS IN THE POLICY OF THE EUROPEAN UNION

The issue of organising efficient transport within Europe is one of the areas of a common policy of the European Union, shaped for over 30 years. Poland has been participating in this creative process since May 1, 2004. The intensity of the development of transport and the economy of individual countries that do not only belong to the Community but also have a significant impact on changes in the European Union's transport policy aimed at improving the course of pan-European transport corridors. In parallel with the creation of an effective European transport network, the rapid economic development of the regions belonging to the Union, including Poland, is becoming increasingly important. This article aims to discuss the issue of the development of the trans-European transport corridors, which also passes through the territory of Poland. In addition, this paper aims to present changes in EU policy concerning the shaping of transport infrastructure in Europe, following which a single transport network is to be created soon, meeting the communication and economic needs of the countries belonging to the Community.

Correction to: Identifying Efficient Transport Pathways in Early‑Wood Timber: Insights from 3D X‑ray CT Imaging of Softwood in the Presence of Flow

A correction to this paper has been published: https://doi.org/10.1007/s11242-021-01569-3