Transport via Niemann-Pick C1 Like 1 contributes to the intestinal absorption of ubiquinone

Ubiquinone, which is a component in the electron-transport systems of mitochondria, is essential for various activities related to energy metabolism, but the detailed absorption mechanism of ubiquinone is not clear. On the other hand, Niemann-Pick C1 Like 1 (NPC1L1) is involved in the intestinal absorption of fat-soluble components such as cholesterol. In this study, we investigated whether the intestinal absorption of ubiquinone was transported by NPC1L1 as is cholesterol. In this study, coenzyme q10 (CoQ10) and coenzyme q9 (CoQ9) were used as models of ubiquinone. The transport activity of ubiquinone was increased significantly in NPC1L1-overexpressed Madin-Darby canine kidney (MDCK) cells compared with that in pMAM2-BSD vector-transfected MDCK cells and the uptake of ubiquinone was decreased in the presence of ezetimibe, an inhibitor of NPC1L1. These results indicate that NPC1L1 mediates the transport of ubiquinone. Furthermore, to clarify the effect of NPC1L1 on the intestinal absorption of CoQ10, emulsified CoQ10 was orally administered to Wistar rats, and the plasma concentration was measured. The plasma concentration of CoQ10 was significantly decreased by coadministration of ezetimibe and CoQ10 compared to that with administration of only CoQ10. This result indicates that the intestinal absorption of CoQ10 is mediated by NPC1L1. (C) 2020 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved

An Approach to Improve Intestinal Absorption of Poorly Absorbed Water-Insoluble Components via Niemann Pick C1-Like 1

Dietary and biliary cholesterol absorption contributes to the maintenance of tight control of cholesterol homeostasis. Cholesterol is present as mixed micelles formed by bile salts and phospholipids in the intestinal lumen. Recently, Niemann Pick Cl-Like 1 (NPC1L1) transporter was identified as being critical for cholesterol absorption. However, the uptake mechanism of an enveloped substrate of NPC1L1 in whole lipid emulsion particles remains unclear. In this study, we investigated the uptake mechanism of a substrate of NPC1L1 in lipid emulsion particles. We also investigated whether these particles containing cholesterol can improve the intestinal absorption of other lipophilic components via NPC1L1. The uptake of lysophosphatidylcholine (LPC)-4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-propionic acid saccinimidyl ester (BODIPY), a fluorescently labeled phospholipid, in lipid emulsion particles containing cholesterol (1 mu m) was significantly increased compared to that without cholesterol in Caco-2 cells. On the other hand, its increased uptake was significantly inhibited by ezetimibe, a selective inhibitor of NPC1L1. These results suggested that not only cholesterol but also some components in lipid emulsion particles are taken up into enterocytes via NPC1L1. We also examined an approach to improve intestinal absorption of a poorly absorbed water-insoluble component, coenzyme Q10 (CoQ10), by this mechanism. The uptake of CoQ10 in lipid emulsion particles containing cholesterol was significantly increased compared to that without cholesterol. Its increased uptake was significantly inhibited by ezetimibe. Though it is still not clear whether CoQ10 is a substrate of NPC1L1, there is a potential for improvement of the absorption of poorly absorbed components by lipid emulsion particles containing cholesterol

An Approach to Improve Intestinal Absorption of Poorly Absorbed Water-Insoluble Components <i>via</i> Niemann–Pick C1-Like 1

Dietary and biliary cholesterol absorption contributes to the maintenance of tight control of cholesterol homeostasis. Cholesterol is present as mixed micelles formed by bile salts and phospholipids in the intestinal lumen. Recently, Niemann Pick Cl-Like 1 (NPC1L1) transporter was identified as being critical for cholesterol absorption. However, the uptake mechanism of an enveloped substrate of NPC1L1 in whole lipid emulsion particles remains unclear. In this study, we investigated the uptake mechanism of a substrate of NPC1L1 in lipid emulsion particles. We also investigated whether these particles containing cholesterol can improve the intestinal absorption of other lipophilic components via NPC1L1. The uptake of lysophosphatidylcholine (LPC)-4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-propionic acid saccinimidyl ester (BODIPY), a fluorescently labeled phospholipid, in lipid emulsion particles containing cholesterol (1 mu m) was significantly increased compared to that without cholesterol in Caco-2 cells. On the other hand, its increased uptake was significantly inhibited by ezetimibe, a selective inhibitor of NPC1L1. These results suggested that not only cholesterol but also some components in lipid emulsion particles are taken up into enterocytes via NPC1L1. We also examined an approach to improve intestinal absorption of a poorly absorbed water-insoluble component, coenzyme Q10 (CoQ10), by this mechanism. The uptake of CoQ10 in lipid emulsion particles containing cholesterol was significantly increased compared to that without cholesterol. Its increased uptake was significantly inhibited by ezetimibe. Though it is still not clear whether CoQ10 is a substrate of NPC1L1, there is a potential for improvement of the absorption of poorly absorbed components by lipid emulsion particles containing cholesterol