The anti-inflammatory and immunomodulatory potential of braylin: Pharmacological properties and mechanisms by in silico, in vitro and in vivo approaches

PLoS One. 2017 Jun 8;12(6):e0179174. doi: 10.1371/journal.pone.0179174. eCollection 2017.

Abstract

Braylin belongs to the group of natural coumarins, a group of compounds with a wide range of pharmacological properties. Here we characterized the pharmacological properties of braylin in vitro, in silico and in vivo in models of inflammatory/immune responses. In in vitro assays, braylin exhibited concentration-dependent suppressive activity on activated macrophages. Braylin (10-40 μM) reduced the production of nitrite, IL-1β, TNF-α and IL-6 by J774 cells or peritoneal exudate macrophages stimulated with LPS and IFN-γ. Molecular docking calculations suggested that braylin present an interaction pose to act as a glucocorticoid receptor ligand. Corroborating this idea, the inhibitory effect of braylin on macrophages was prevented by RU486, a glucocorticoid receptor antagonist. Furthermore, treatment with braylin strongly reduced the NF-κB-dependent transcriptional activity on RAW 264.7 cells. Using the complete Freund's adjuvant (CFA)-induced paw inflammation model in mice, the pharmacological properties of braylin were demonstrated in vivo. Braylin (12.5-100 mg/kg) produced dose-related antinociceptive and antiedematogenic effects on CFA model. Braylin did not produce antinociception on the tail flick and hot plate tests in mice, suggesting that braylin-induced antinociception is not a centrally-mediated action. Braylin exhibited immunomodulatory properties on the CFA model, inhibiting the production of pro-inflammatory cytokines IL-1β, TNF-α and IL-6, while increased the anti-inflammatory cytokine TGF-β. Our results show, for the first time, anti-inflammatory, antinociceptive and immunomodulatory effects of braylin, which possibly act through the glucocorticoid receptor activation and by inhibition of the transcriptional activity of NF-κB. Because braylin is a phosphodiesterase-4 inhibitor, this coumarin could represent an ideal prototype of glucocorticoid receptor ligand, able to induce synergic immunomodulatory effects.

MeSH terms

  • Adjuvants, Immunologic
  • Animals
  • Anti-Inflammatory Agents / chemistry
  • Anti-Inflammatory Agents / pharmacology*
  • Cell Death / drug effects
  • Cell Line
  • Computer Simulation*
  • Coumarins / chemistry
  • Coumarins / pharmacology*
  • Cytokines / biosynthesis
  • Immunologic Factors / chemistry
  • Immunologic Factors / pharmacology*
  • Inflammation / pathology
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Male
  • Mice
  • Molecular Docking Simulation
  • NF-kappa B / metabolism
  • Nitric Oxide / biosynthesis
  • Receptors, Glucocorticoid / metabolism
  • Transcription, Genetic / drug effects

Substances

  • Adjuvants, Immunologic
  • Anti-Inflammatory Agents
  • Coumarins
  • Cytokines
  • Immunologic Factors
  • NF-kappa B
  • Receptors, Glucocorticoid
  • Nitric Oxide

Grants and funding

This work was supported by Fundação de Amparo à Pesquisa do Estado da Bahia — FAPESB, grant numbers: DTE 0046/2011 CFV, PNX0009/2009 MBPS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.