title: The Cytoprotective Effects of E-α-(4-Methoxyphenyl)-2',3,4,4'-Tetramethoxychalcone (E-α-p-OMe-C6H4-TMC)--A Novel and Non-Cytotoxic HO-1 Inducer.
abstract: Cell protection against different noxious stimuli like oxidative stress or chemical toxins plays a central role in the treatment of many diseases. The inducible heme oxygenase isoform, heme oxygenase-1 (HO-1), is known to protect cells against a variety of harmful conditions including apoptosis. Because a number of medium strong electrophiles from a series of α-X-substituted 2',3,4,4'-tetramethoxychalcones (α-X-TMCs, X = H, F, Cl, Br, I, CN, Me, p-NO2-C6H4, Ph, p-OMe-C6H4, NO2, CF3, COOEt, COOH) had proven to activate Nrf2 resulting in HO-1 induction and inhibit NF-κB downstream target genes, their protective effect against staurosporine induced apoptosis and reactive oxygen species (ROS) production was investigated. RAW264.7 macrophages treated with 19 different chalcones (15 α-X-TMCs, chalcone, 2'-hydroxychalcone, calythropsin and 2'-hydroxy-3,4,4'-trimethoxychalcone) prior to staurosporine treatment were analyzed for apoptosis and ROS production, as well as HO-1 protein expression and enzyme activity. Additionally, Nrf2 and NF-κB activity was assessed. We found that amongst all tested chalcones only E-α-(4-methoxyphenyl)-2',3,4,4'-tetramethoxychalcone (E-α-p-OMe-C6H4-TMC) demonstrated a distinct, statistically significant antiapoptotic effect in a dose dependent manner, showing no toxic effects, while its double bond isomer Z-α-p-OMe-C6H4-TMC displayed no significant activity. Also, E-α-p-OMe-C6H4-TMC induced HO-1 protein expression and increased HO-1 activity, whilst inhibition of HO-1 by SnPP-IX abolished its antiapoptotic effect. The only weakly electrophilic chalcone E-α-p-OMe-C6H4-TMC reduced the staurosporine triggered formation of ROS, while inducing the translocation of Nrf2 into the nucleus. Furthermore, staurosporine induced NF-κB activity was attenuated following E-α-p-OMe-C6H4-TMC treatment. Overall, E-α-p-OMe-C6H4-TMC demonstrated its effective cytoprotective potential via a non-toxic induction of HO-1 in RAW264.7 macrophages. The observed cytoprotective effect may partly be related to both, the activation of the Nrf2- and inhibition of the NF-κB pathway.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Kai B
authors.initials: KB
authors.lastname: Kaufmann
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany.
authors.forename: Nafisah
authors.initials: N
authors.lastname: Al-Rifai
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Ulbrich
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Nils
authors.initials: N
authors.lastname: Schallner
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany.
authors.forename: Hannelore
authors.initials: H
authors.lastname: Rücker
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Enzinger
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany.
authors.forename: Hermina
authors.initials: H
authors.lastname: Petkes
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany.|Institute of Pharmaceutical Biology, University of Regensburg, Regensburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Pitzl
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Goebel
authors.affiliation: Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Amslinger
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002599:Chalcone / Q000031:analogs & derivatives / Q000737:chemistry; D047188:Chalcones / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019610:Cytoprotection / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D051547:Heme Oxygenase-1 / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects; D008565:Membrane Proteins / Q000187:drug effects*; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000037:antagonists & inhibitors; D052002:NF-kappa B p50 Subunit / Q000037:antagonists & inhibitors; D018384:Oxidative Stress; D021381:Protein Transport; D000067996:RAW 264.7 Cells; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D047188:Chalcones; D008565:Membrane Proteins; D051267:NF-E2-Related Factor 2; D052002:NF-kappa B p50 Subunit; C495636:Nfe2l2 protein, mouse; D017382:Reactive Oxygen Species; C000608611:alpha-(4-methoxyphenyl)-2',3,4,4'-tetramethoxychalcone; C073701:Nfkb1 protein, mouse; C085139:calythropsin; D002599:Chalcone; D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse