Chemical composition, antioxidant and anti-inflammatory properties of Monarda didyma L. essential oil

PeerJ. 2022 Nov 21:10:e14433. doi: 10.7717/peerj.14433. eCollection 2022.

Abstract

In the present study, Monarda didyma L. essential oil (isolated from the flowering aerial parts of the plant) was examined to characterize its chemotype and to evaluate, in addition to the quali-quantitative chemical analysis, the associated antioxidant and anti-inflammatory activities. The plants were grown in central Italy, Urbino (PU), Marche region. Different analyses (TLC, GC-FID, GC-MS and 1H-NMR) allowed the identification of twenty compounds among which carvacrol, p-cymene and thymol were the most abundant. On this basis, the chemotype examined in the present study was indicated as Monarda didyma ct. carvacrol. The antioxidant effect was assessed by DPPH assay. Moreover, this chemotype was investigated for the anti-inflammatory effect in an in vitro setting (i.e., LPS-stimulated U937 cells). The decreased expression of pro-inflammatory cytokine IL-6 and the increased expression of miR-146a are suggestive of the involvement of the Toll-like receptor-4 signaling pathway. Although further studies are needed to better investigate the action mechanism/s underlying the results observed in the experimental setting, our findings show that M. didyma essential oil is rich in bioactive compounds (mainly aromatic monoterpenes and phenolic monoterpenes) which are most likely responsible for its beneficial effect.

Keywords: LPS; Monoterpenes; Monoterpenoids; Scarlet beebalm; TLR-4; microRNAs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / pharmacology
  • Monarda* / chemistry
  • Monoterpenes / pharmacology
  • Oils, Volatile* / pharmacology
  • Plants

Substances

  • Oils, Volatile
  • carvacrol
  • Antioxidants
  • Monoterpenes

Grants and funding

The present project was made possible thanks to the ERASMUS+ Mobility for Studies programme which awarded Rossella D’Adderio a scholarship and enabled her to spend a period of continuous study at the Université de Paris, Faculté de Santé, Pharmacie that has entered into an agreement with the University of Urbino Carlo Bo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.