title: Nonprenylated Xanthones from Gentiana lutea, Frasera caroliniensis, and Centaurium erythraea as Novel Inhibitors of Vascular Smooth Muscle Cell Proliferation.
abstract: Aberrant proliferation of vascular smooth muscle cells (VSMC) plays a major role in restenosis, the pathological renarrowing of the blood vessel lumen after surgical treatment of stenosis. Since available anti-proliferative pharmaceuticals produce unfavorable side effects, there is high demand for the identification of novel VSMC proliferation inhibitors. A natural product screening approach using a resazurin conversion assay enabled the identification of gentisin (1) from Gentiana lutea as a novel inhibitor of VSMC proliferation with an IC50 value of 7.84 µM. Aiming to identify further anti-proliferative compounds, 13 additional nonprenylated xanthones, isolated from different plant species, were also tested. While some compounds showed no or moderate activity at 30 µM, 1-hydroxy-2,3,4,5-tetramethoxyxanthone (4), swerchirin (6), and methylswertianin (7) showed IC50 values between 10.2 and 12.5 µM. The anti-proliferative effect of 1, 4, 6, and 7 was confirmed by the quantification of DNA synthesis (BrdU incorporation) in VSMC. Cell death quantification (determined by LDH release in the culture medium) revealed that the compounds are not cytotoxic in the investigated concentration range. In conclusion, nonprenylated xanthones are identified as novel, non-toxic VSMC proliferation inhibitors, which might contribute to the development of new therapeutic applications to combat restenosis.
authors.affiliation: Institute of Pharmacy/Pharmacognosy, University of Innsbruck, 6020 Innsbruck, Austria. birgit.waltenberger@uibk.ac.at.
authors.forename: Birgit
authors.initials: B
authors.lastname: Waltenberger
authors.affiliation: Department of Pharmacognosy, University of Vienna, 1090 Vienna, Austria. liurongxia107@outlook.com.|School of Pharmacy, Yantai University, 264005 Yantai, China. liurongxia107@outlook.com.
authors.forename: Rongxia
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Pharmacognosy, University of Vienna, 1090 Vienna, Austria. atanas.atanasov@univie.ac.at.
authors.forename: Atanas G
authors.initials: AG
authors.lastname: Atanasov
authors.affiliation: Institute of Pharmacy/Pharmacognosy, University of Innsbruck, 6020 Innsbruck, Austria. stefan.schwaiger@uibk.ac.at.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwaiger
authors.affiliation: Department of Pharmacognosy, University of Vienna, 1090 Vienna, Austria. elke.heiss@univie.ac.at.
authors.forename: Elke H
authors.initials: EH
authors.lastname: Heiss
authors.affiliation: Department of Pharmacognosy, University of Vienna, 1090 Vienna, Austria. verena.dirsch@univie.ac.at.
authors.forename: Verena M
authors.initials: VM
authors.lastname: Dirsch
authors.affiliation: Institute of Pharmacy/Pharmacognosy, University of Innsbruck, 6020 Innsbruck, Austria. hermann.stuppner@uibk.ac.at.
authors.forename: Hermann
authors.initials: H
authors.lastname: Stuppner
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D029966:Centaurium / Q000737:chemistry*; D030012:Gentiana / Q000737:chemistry*; D029965:Gentianaceae / Q000737:chemistry*; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*; D051381:Rats; D044004:Xanthones / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D044004:Xanthones
keywords: Centaurium erythraea; Frasera caroliniensis; Gentiana lutea; Gentianaceae; atherosclerosis; bitter plants; gentisin; restenosis; vascular smooth muscle cell proliferation; xanthones.