Dose-Dependent Effects of Clove Oil on Human Nasal Epithelial Cells In Vitro

The purpose of this study was to investigate how Clove Oil interacts with epithelial cells in human nasal tissue.

Tissue samples taken during surgery were immediately submerged in sterile PBS containing antibiotics and transferred to the lab under cold-chain conditions. After several washes to remove residual blood or debris, the samples were centrifuged at 300 g. Before enzymatic digestion with 0.25% trypsin-EDTA at 37 °C, the tissue was deliberately broken down. Complete DMEM/F-12 medium neutralized the enzyme activity. To ensure cell adhesion and viability testing before treatment, 96-well culture plates were used. Clove oil was added to cells at doses of 1, 5, 15, 25, 50, 75, and 100 µL over 24 hours. To assess cell metabolic activity, the MTT colorimetric assay was used.

The inhibitory nature of the dose-response relationship was demonstrated by nonlinear regression analysis. The logIC50 value was 1.616, corresponding to an IC50 of 41.29 µL. There was a strong association between product dose and cytotoxic response, as evidenced by a consistent, reproducible effect and a high coefficient of determination (R2=0.9172).Clove oil treatment resulted in a concentration-dependent reduction in cellular metabolic activity, as assessed by the MTT assay. The treated cells showed a clear decrease in cell viability as the product volume increased, whereas the negative control group maintained 100% cell viability. In addition, statistical analysis showed that all clove oil concentrations significantly reduced cell viability compared with untreated controls. Further evidence of a dose-response relationship was that statistical significance increased with the addition of clove oil.

Despite clove oil's promise in otolaryngology, it is essential to establish a safe therapy window. For conditions in which the function of the mucosal barrier and the health of the epithelial cells are critical, such as allergic rhinitis, rhinosinusitis, or upper respiratory tract infections, it can be administered topically by inhalation, nasal spray, or other nasal drug delivery systems. Further study, including in vivo tests, mucociliary function evaluations, and long-term exposure trials, is needed to establish its safety profile and guide its appropriate use in otorhinolaryngology.