1,8-Cineole is chemically classified as a monoterpenoid. This molecule easily penetrates body cells and acts by inhibiting the IκBα molecule, thereby preventing the activation and nuclear translocation of the key inflammatory mediator NF-κB p65. As a result, intracellular inflammatory pathways are interrupted.

In ciliated epithelial cells of the bronchi, cineole halts the expression of mucin genes, which are responsible for producing mucus polysaccharides. This leads to a reduction in mucus production.

Cineole also acts on goblet cells in the lungs, decreasing mucus secretion from the bronchial mucosal layers. By reducing mucus levels, it helps keep the airways open and facilitates easier breathing.

By regulating NF-κB, cineole reduces or inhibits the expression of inflammatory cytokines such as TNF-α, IL-1β, and IL-6. These cytokines typically recruit immune cells like macrophages and neutrophils to inflamed areas, increasing local heat and pain. Cineole rapidly suppresses these responses, leading to a reduction in inflammation, warmth, and discomfort.

Additionally, nerve cells in the respiratory tract (e.g., in the nose and bronchi) are also influenced by cineole. Treatment with herbal agonists like cineole has been shown to reduce irritation in the airways and help stop the cough reflex.