Inhaled 1,8-Cineole Reduces Inflammatory Parameters in Airways of Ovalbumin-Challenged Guinea Pigs

Abstract

Eucalyptol, also known as 1,8-cineole, is a monoterpene traditionally used to treat respiratory disorders due to its secretolytic properties. In addition to its myorelaxant effects, it also has anti-inflammatory actions in vitro. In this study, we aimed to evaluate the efficacy of acute treatment with 1,8-cineole on reducing airway inflammatory parameters. Ovalbumin (OVA)-sensitized guinea pigs were submitted to antigenic challenge (OVA) with or without pre-treatment with a single dose of 1,8-cineole administered by inhalation. Airway inflammatory parameters were reduced or absent in 1,8-cineole-treated animals as compared with untreated guinea pigs. Acute treatment with 1,8-cineole impaired the development of airway hyperresponsiveness to carbachol in isolated tracheal rings. Levels of the pro-inflammatory cytokines TNFa and IL-1b was lower in bronchoalveolar lavage fluid (BALF) of 1,8-cineol-treated guinea pigs than in untreated animals. 1,8-Cineole impaired the OVA-induced increase of the myeloperoxidase activity in BALF. 1,8-Cineole also prevented the reduction of the mucociliary clearance induced by the antigen presentation. The present investigation provides evidence that inhaled 1,8-cineole prevents hyperresponsiveness and inhibits inflammation in airways of ovalbumin-challenged guinea pigs.

Anti-inflammatory and cicatrizing activities of thymol, a monoterpene of the essential oil from Lippia gracilis, in rodents

“…Other monoterpenes have been reported to possess antiinflammatory activity in animal models (Bastos et al, 2011;Guimarães et al, 2012;Peana et al, 2002). However, both the anti-inflammatory action in vivo and cicatrizing activity of thymol are still not demonstrated.…”

Effect of <i>1.8-Cineole</i> in <i>Dermatophagoides pteronyssinus</i>-Stimulated Bronchial Epithelial Cells and Mouse Model of Asthma

“…1.8-Cineole strongly inhibited TNF-α and IL-1β level controlling airway mucus hypersecretion in asthma. 15) It also reduced the production of cytokines such as leukotriene B4 (LTB4) and prostaglandin E2 (PGE2) in human monocytes obtained from asthma patients. 13) However, the literature contains very little experimental data on how 1.8-cineole affects human epithelial cells stimulated by allergens such as HDMs.…”

Effect of Eucalyptus Oil Inhalation on Pain and Inflammatory Responses after Total Knee Replacement: A Randomized Clinical Trial

“…A possible pathway for this explanation may include the olfactory system. Autonomic nervous system is affected by odorants, thus inhalation of essential oil is direct actions on the autonomic nervous system via olfactory system [19, 20]. Recent study has shown that olfactory stimulation with lavender essential oil and its active component, linalool reduced the sympathetic nerve activity in rats [21].…”

“…Moreover, 1,8-cineole was found to reduce cytokines that cause inflammation in guinea pigs [20], and to significantly reduce edema and CRP at sites of inflammation throughout the entire body [26]. These studies prompted us to hypothesize that eucalyptus oil would reduce pain following TKR by lessening inflammatory reactions.…”