Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2020 Aug 3;10(8):1139.
doi: 10.3390/biom10081139.

Immunomodulatory Activities of Selected Essential Oils

Georg Sandner  1 , Mara Heckmann  1   2 , Julian Weghuber  1   2
Affiliations
Review

Immunomodulatory Activities of Selected Essential Oils

Georg Sandner et al. Biomolecules. .

Abstract

Recently, the application of herbal medicine for the prevention and treatment of diseases has gained increasing attention. Essential oils (EOs) are generally known to exert various pharmacological effects, such as antiallergic, anticancer, anti-inflammatory, and immunomodulatory effects. Current literature involving in vitro and in vivo studies indicates the potential of various herbal essential oils as suitable immunomodulators for the alternative treatment of infectious or immune diseases. This review highlights the cellular effects induced by EOs, as well as the molecular impacts of EOs on cytokines, immunoglobulins, or regulatory pathways. The results reviewed in this article revealed a significant reduction in relevant proinflammatory cytokines, as well as induction of anti-inflammatory markers. Remarkably, very little clinical study data involving the immunomodulatory effects of EOs are available. Furthermore, several studies led to contradictory results, emphasizing the need for a multiapproach system to better characterize EOs. While immunomodulatory effects were reported, the toxic potential of EOs must be clearly considered in order to secure future applications.

Keywords: clove; essential oils; eucalyptus; immunomodulatory; lavender; tea tree.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Figures

Figure 1
Figure 1
Overview of the mammalian innate and adaptive immune systems and the regulatory effects of selected essential oils on various cytokines shown as dots (adapted from [11]). Antigen-presenting cells (APCs), such as dendritic cells or macrophages, are recruited to the infection site. The released cytokines further activate natural killer cells and lead to the maturation of T cells. The reviewed studies identified multiple cytokines that were downregulated by eucalyptus, tea tree, clove, and lavender EOs. Specific interleukins and other factors are also expressed in other cell types. Most reviewed research articles focused on monocytes and activated macrophages. Hence, only those effects are highlighted in the figure.
Figure 2
Figure 2
Chemical structures of the main components of the four selected EOs.
See this image and copyright information in PMC

References

    1. Hotta M., Nakata R., Katsukawa M., Hori K., Takahashi S., Inoue H. Carvacrol, a component of thyme oil, activates PPARα and γ and suppresses COX-2 expression. J. Lipid Res. 2009;51:132–139. doi: 10.1194/jlr.M900255-JLR200. - DOI - PMC - PubMed
    1. Hart P.H., Brand C., Carson C.F., Riley T.V., Prager R.H., Finlay-Jones J.J. Terpinen-4-ol, the main component of the essential oil of Melaleuca alternifolia (tea tree oil), suppresses inflammatory mediator production by activated human monocytes. Inflamm. Res. 2000;49:619–626. doi: 10.1007/s000110050639. - DOI - PubMed
    1. Nogueira M.N.M., Aquino S.G., Rossa Junior C., Spolidorio D.M.P. Terpinen-4-ol and alpha-terpineol (tea tree oil components) inhibit the production of IL-1β, IL-6 and IL-10 on human macrophages. Inflamm. Res. 2014;63:769–778. doi: 10.1007/s00011-014-0749-x. - DOI - PubMed
    1. Marshall J.S., Warrington R., Watson W., Kim H.L. An introduction to immunology and immunopathology. Allergy Asthma Clin. Immunol. 2018;14:49. doi: 10.1186/s13223-018-0278-1. - DOI - PMC - PubMed
    1. Burt S. Essential oils: Their antibacterial properties and potential applications in foods—A review. Int. J. Food Microbiol. 2004;94:223–253. doi: 10.1016/j.ijfoodmicro.2004.03.022. - DOI - PubMed

Publication types

MeSH terms

LinkOut - more resources