Inhibitory activity of 1,8-cineol (eucalyptol) on cytokine production in cultured human lymphocytes and monocytes

Pulm Pharmacol Ther. 2004;17(5):281-7. doi: 10.1016/j.pupt.2004.06.002.


Background: The therapeutic value of secretolytic agents in COPD and asthma is still disputed. For this reason, in a preclinical study we aimed to test the potential anti-inflammatory efficacy of 1,8-cineol (eucalyptol) in inhibiting polyclonal stimulated cytokine production by human unselected lymphocytes and LPS-stimulated monocytes.

Methods: Cytokine production was determined following 20 h of incubation cells with 1,8-cineol simultaneously with the stimuli in culture supernatants by enzyme immunoassay.

Results: Therapeutic concentrations of 1,8-cineol (1.5 microg/ml=10(-5)M) inhibited significantly (n=13-19, p=0.0001) cytokine production in lymphocytes of TNF-alpha > IL-1beta> IL-4> IL-5 by 92, 84, 70, and 65%, respectively. Cytokine production in monocytes of TNF-alpha > IL-1beta> IL-6> IL-8 was also significantly (n=7-16, p<0.001) inhibited by 99, 84, 76, and 65%, respectively. In the presence of 1,8-cineol (0.15 microg/ml=10(-6)M) production of TNF-alpha>IL-1beta by monocytes and of IL-1beta> TNF-alpha by lymph-ocytes was significantly inhibited by 77, 61 and by 36, 16%, respectively. 1,8-cineol (10(-6)M) had a larger impact on TNF-alpha and IL-1beta-production in monocytes compared to lymphocytes (p<0.03) and similar effects (p>0.59) at therapeutically relevant concentrations of 1,8-Cineol (10(-5)M).

Conclusion: These results characterize 1,8-cineol as strong inhibitor of TNF-alpha and IL-1beta and suggest smaller effects on chemotactic cytokines. This is increasing evidence for the role of 1,8-cineol to control airway mucus hypersecretion by cytokine inhibition, suggesting long-term treatment to reduce exacerbations in asthma, sinusitis and COPD.

MeSH terms

  • Anti-Inflammatory Agents / pharmacology*
  • Cells, Cultured
  • Cyclohexanols / pharmacology*
  • Cytokines / antagonists & inhibitors*
  • Cytokines / biosynthesis
  • Enzyme-Linked Immunosorbent Assay
  • Eucalyptol
  • Humans
  • Lymphocytes / metabolism*
  • Monocytes / metabolism*
  • Monoterpenes / pharmacology*
  • Th1 Cells / metabolism
  • Th2 Cells / metabolism


  • Anti-Inflammatory Agents
  • Cyclohexanols
  • Cytokines
  • Monoterpenes
  • Eucalyptol