title: Caco-2 Permeability Studies and In Vitro hERG Liability Assessment of Tryptanthrin and Indolinone.
abstract: Tryptanthrin and (E,Z)-3-(4-hydroxy-3,5-dimethoxybenzylidene)indolinone (indolinone) were recently isolated from Isatis tinctoria as potent anti-inflammatory and antiallergic alkaloids, and shown to inhibit COX-2, 5-LOX catalyzed leukotriene synthesis, and mast cell degranulation at low µM to nM concentrations. To assess their suitability for oral administration, we screened the compounds in an in vitro intestinal permeability assay using human colonic adenocarcinoma cells. For exact quantification of the compounds, validated UPLC-MS/MS methods were used. Tryptanthrin displayed high permeability (apparent permeability coefficient > 32.0 × 10(-6) cm/s) across the cell monolayer. The efflux ratio below 2 (< 1.12) and unchanged apparent permeability coefficient values in the presence of the P-glycoprotein inhibitor verapamil (50 µM) indicated that tryptanthrin was not involved in P-glycoprotein interactions. For indolinone, a low recovery was found in the human colon adenocarcinoma cell assay. High-resolution mass spectrometry pointed to extensive phase II metabolism of indolinone (sulfation and glucuronidation). Possible cardiotoxic liability of the compounds was assessed in vitro by measurement of an inhibitory effect on human ether-a-go-go-related gene tail currents in stably transfected HEK 293 cells using the patch clamp technique. Low human ether-a-go-go-related gene inhibition was found for tryptanthrin (IC50 > 10 µM) and indolinone (IC50 of 24.96 µM). The analysis of compounds using various in silico methods confirmed favorable pharmacokinetic properties, as well as a slight inhibition of the human ether-a-go-go-related gene potassium channel at micromolar concentrations.
authors.affiliation: Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
authors.forename: Evelyn A
authors.initials: EA
authors.lastname: Jähne
authors.affiliation: Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
authors.forename: Daniela E
authors.initials: DE
authors.lastname: Eigenmann
authors.affiliation: Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Moradi-Afrapoli
authors.affiliation: Institute for Pharma Technology, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland.
authors.forename: Sheela
authors.initials: S
authors.lastname: Verjee
authors.affiliation: Institute for Pharma Technology, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland.
authors.forename: Veronika
authors.initials: V
authors.lastname: Butterweck
authors.affiliation: B'SYS GmbH, The Ionchannel Company, Witterswil, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Hebeisen
authors.affiliation: Institute for Chemistry and Bioanalytics, School of Life Sciences, University of Applied Sciences, Northwestern Switzerland, Muttenz, Switzerland.
authors.forename: Timm
authors.initials: T
authors.lastname: Hettich
authors.affiliation: Institute for Chemistry and Bioanalytics, School of Life Sciences, University of Applied Sciences, Northwestern Switzerland, Muttenz, Switzerland.
authors.forename: Götz
authors.initials: G
authors.lastname: Schlotterbeck
authors.affiliation: Molecular Modeling, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Smieško
authors.affiliation: Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hamburger
authors.affiliation: Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland.
authors.forename: Mouhssin
authors.initials: M
authors.lastname: Oufir
mesh_terms: D018926:Anti-Allergic Agents / Q000493:pharmacokinetics*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000493:pharmacokinetics*; D018938:Caco-2 Cells; D002463:Cell Membrane Permeability; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D057809:HEK293 Cells; D006801:Humans; D007211:Indoles / Q000493:pharmacokinetics*; D007408:Intestinal Absorption; D031219:Isatis / Q000737:chemistry; D011748:Pyrogallol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D011799:Quinazolines / Q000493:pharmacokinetics*; D053719:Tandem Mass Spectrometry
chemical_list: C000614731:3-(4-hydroxy-3,5-dimethoxybenzylidene)indolinone; D018926:Anti-Allergic Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D007211:Indoles; C503753:Indolinone A; D011799:Quinazolines; D011748:Pyrogallol; C046243:tryptanthrine