Characterisation of the molecular interactions between primary bile acids and fractionated lupin cotyledons (Lupinus angustifolius L.)

Susanne Naumann; Ute Schweiggert-Weisz; Peter Eisner

doi:10.1016/j.foodchem.2020.126780

Characterisation of the molecular interactions between primary bile acids and fractionated lupin cotyledons (Lupinus angustifolius L.)

Food Chem. 2020 Apr 9:323:126780. doi: 10.1016/j.foodchem.2020.126780. Online ahead of print.

Authors

Susanne Naumann¹, Ute Schweiggert-Weisz², Peter Eisner³

Affiliations

¹ ZIEL-Institute for Food & Health, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany; Fraunhofer Institute for Process Engineering and Packaging (IVV), 85354 Freising, Germany. Electronic address: susanne.naumann@ivv.fraunhofer.de.
² Fraunhofer Institute for Process Engineering and Packaging (IVV), 85354 Freising, Germany. Electronic address: ute.weisz@ivv.fraunhofer.de.
³ ZIEL-Institute for Food & Health, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany; Fraunhofer Institute for Process Engineering and Packaging (IVV), 85354 Freising, Germany. Electronic address: peter.eisner@ivv.fraunhofer.de.

PMID: 32334300
DOI: 10.1016/j.foodchem.2020.126780

Abstract

Interactions between bile acids and plant-based materials, and the related feedback mechanisms in enterohepatic circulation, have been considered targets for lowering cholesterol. This study aimed to identify lupin compounds that interact with primary bile acids on molecular level. Lupin cotyledons were fractionated and bile acid adsorbing activities were investigated using in vitro digestion, equilibrium dialysis and kinetic analyses. Protein- and fibre-enriched fractions significantly (p ≤ 0.05) adsorbed chenodesoxycholic acids (up to 2.33 µmol/100 g DM). Alcohol purification showed that bile acid adsorption is independent of protein and fibre structures. Moreover, high adsorption was observed with an alcohol extract (6.97 µmol chenodesoxycholic acids/100 g DM) that was rich in phytochemicals, such as flavonoids (1842 mg/100 g DM). These results suggest the formation of hydrophobic interactions between polyphenols and bile acids. Further studies of molecular mechanisms are required to define the contributions of polyphenols to the cholesterol-lowering actions of lupins.

Keywords: Bile acid binding; Bile acid excretion; Cholesterol; Flavonoid; In vitro digestion; Polyphenol; glycochenodeoxycholic acid (PubChem CID: 12544); glycocholic acid (PubChem CID: 10140); taurochenodeoxycholic acid (PubChem CID: 387316); taurocholic acid (PubChem CID: 6675); vitexin (PubChem CID: 5280441).