Imbricaric acid and perlatolic acid: multi-targeting anti-inflammatory depsides from Cetrelia monachorum

PLoS One. 2013 Oct 9;8(10):e76929. doi: 10.1371/journal.pone.0076929. eCollection 2013.

Abstract

In vitro screening of 17 Alpine lichen species for their inhibitory activity against 5-lipoxygenase, microsomal prostaglandin E2 synthase-1 and nuclear factor kappa B revealed Cetrelia monachorum (Zahlbr.) W.L. Culb. & C.F. Culb. As conceivable source for novel anti-inflammatory compounds. Phytochemical investigation of the ethanolic crude extract resulted in the isolation and identification of 11 constituents, belonging to depsides and derivatives of orsellinic acid, olivetolic acid and olivetol. The two depsides imbricaric acid (4) and perlatolic acid (5) approved dual inhibitory activities on microsomal prostaglandin E2 synthase-1 (IC50 = 1.9 and 0.4 µM, resp.) and on 5-lipoxygenase tested in a cell-based assay (IC50 = 5.3 and 1.8 µM, resp.) and on purified enzyme (IC50 = 3.5 and 0.4 µM, resp.). Additionally, these two main constituents quantified in the extract with 15.22% (4) and 9.10% (5) showed significant inhibition of tumor necrosis factor alpha-induced nuclear factor kappa B activation in luciferase reporter cells with IC50 values of 2.0 and 7.0 µM, respectively. In a murine in vivo model of inflammation, 5 impaired the inflammatory, thioglycollate-induced recruitment of leukocytes to the peritoneum. The potent inhibitory effects on the three identified targets attest 4 and 5 a pronounced multi-target anti-inflammatory profile which warrants further investigation on their pharmacokinetics and in vivo efficacy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / isolation & purification
  • Anti-Inflammatory Agents / pharmacology*
  • Ascomycota / chemistry*
  • Benzoates / isolation & purification
  • Benzoates / pharmacology*
  • Depsides / isolation & purification
  • Depsides / pharmacology*
  • Drug Evaluation, Preclinical
  • HEK293 Cells
  • Humans
  • Inhibitory Concentration 50
  • Leukocytes / drug effects
  • Leukocytes / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Peritoneum / drug effects
  • Peritoneum / immunology

Substances

  • Anti-Inflammatory Agents
  • Benzoates
  • Depsides
  • imbricaric acid
  • perlatolic acid

Grants and funding

This work was supported by the National Research Network “Drugs from Nature Targeting Inflammation” (subprojects S10703, S10704, and S10713) granted by the Austrian Science Fund (FWF). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.