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

PLoS One. 2015 Nov 13;10(11):e0142932. doi: 10.1371/journal.pone.0142932. eCollection 2015.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Cell Line
  • Chalcone / analogs & derivatives
  • Chalcone / chemistry
  • Chalcones / chemistry*
  • Crystallography, X-Ray
  • Cytoprotection / drug effects
  • Dose-Response Relationship, Drug
  • Flow Cytometry
  • Gene Expression Regulation
  • Heme Oxygenase-1 / drug effects*
  • Macrophages / drug effects
  • Membrane Proteins / drug effects*
  • Mice
  • NF-E2-Related Factor 2 / antagonists & inhibitors
  • NF-kappa B p50 Subunit / antagonists & inhibitors
  • Oxidative Stress
  • Protein Transport
  • RAW 264.7 Cells
  • Reactive Oxygen Species / metabolism

Substances

  • Chalcones
  • Membrane Proteins
  • NF-E2-Related Factor 2
  • NF-kappa B p50 Subunit
  • Nfe2l2 protein, mouse
  • Reactive Oxygen Species
  • alpha-(4-methoxyphenyl)-2',3,4,4'-tetramethoxychalcone
  • Nfkb1 protein, mouse
  • calythropsin
  • Chalcone
  • Heme Oxygenase-1
  • Hmox1 protein, mouse

Grants and funding

Liebig Scholarship Fonds der Chemischen Industrie DAAD Ph.D. scholarship.