Eucalyptus oil reduces allergic reactions and suppresses mast cell degranulation by downregulating IgE-FcεRI signalling

Abstract

Eucalyptus oil has been used since ancient times for its bactericidal, anti-inflammatory, analgesic and sedative effects. In recent years, the action of Eucalyptus oil has been scientifically proven, and there have been reports that Eucalyptus oil suppresses the production of chemokines, cytokines and lipid mediators in basophils, alveolar macrophages and monocytes. Based on this information, we aimed to verify whether Eucalyptus oil can be used for allergic dermatitis, the incidence of which has been increasing among human skin diseases. This effect was verified using a mouse IgE-mediated local allergic model. In conclusion, topical application of Eucalyptus oil suppressed oedema and vascular permeability enhancement due to IgE-mediated allergic on the skin. In addition, we also verified the degranuration of mast cells, which is a part of its action, and examined whether 1,8-cineole, which is the main component of Eucalyptus oil, suppresses the phosphorylation of PLCγ and p38 directly or indirectly. 1,8-cineole was found to suppress degranulation of mast cells.

1-Iodohexadecane Alleviates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis in Mice: Possible Involvements of the Skin Barrier and Mast Cell SNARE Proteins

“…Our findings support the notion that 1-Iodo suppresses the release of degranulation-mediated granule contents by interfering with SNARE complex formation in mast cells. In an animal model of AD, mast cell degranulation inhibition suppressed β-hexosaminidase, histamine, and cytokine secretion and ameliorated AD-like lesions [ 13 , 48 ]. In the present study, we found that topical treatment with 1-Iodo inhibited mast cell infiltrations into dorsal skin tissues in AD-like model mice, implying that mast cells may be associated with skin lesions ameliorated by 1-Iodo in like model mice.…”

Menthone Inhalation Alleviates Local and Systemic Allergic Inflammation in Ovalbumin-Sensitized and Challenged Asthmatic Mice

“…Phlomis umbrosa root decreases mast cell-dependent allergic reactions and inflammatory cytokine secretion [ 9 ]. Eucalyptus oil has been found to decrease allergic reactions and suppress mast cell degranulation by downregulating IgE-FcεRI signaling [ 7 ]. In the present study, we found that the anti-mast cell degranulation effect of menthone inhalation in the experiment was much better than that of dexamethasone treatment in vivo (PC group).…”

“…Traditional medicine (e.g., natural products) are alternative or complementary treatments for asthma [ 6 ]. Mast cell stabilizers from Phlomis umbrosa root, eucalyptus oil, 8-hydroxyisocapnolactone-2-3-diol, and friedelin (a triterpenoid ketone) have been used to inhibit allergic response, mast cell degranulation, inflammatory cytokine secretion, and IgE-FcεRI signaling [ 3 , 7 , 8 , 9 ]. Recently, particular terpenoids, which are secondary metabolic products rich in different herbal plants and marine organisms, with volatile, antioxidant, anti-inflammatory, and/or Th1/Th2 immunomodulatory characteristics, have been noticed due to their pharmacological potential in the treatment of allergic asthma [ 1 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

Essential Oil from Eucalyptus globulus (Labill.) Activates Complement Receptor-Mediated Phagocytosis and Stimulates Podosome Formation in Human Monocyte-Derived Macrophages

“…Aside from eucalyptol, other components of EO include some terpenes such α-pinene and limonene, present in percentages around 9% and 2%, respectively, and more than 40 other minor compounds present in concentrations lower than 0.2% or in traces [ 18 ]. It has been recently reported that the topical application of Eucalyptus oil suppresses edema and the enhancement of vascular permeability in IgE-mediated allergic dermatitis [ 19 ], and that the rational use of this essential oil can improve the immune function of the respiratory tract as well as the whole immune response [ 20 , 21 ]. Eucalyptus extracts have been also been evaluated among 39 herbal medicines to be used as adjuvants in symptomatic therapy in the context of COVID-19, and the benefit/risk assessment for the Eucalyptus essential oil was found promising, with an overall benefit classified as mild [ 22 ].…”