In Vitro Investigation of the Effects of Octenidine Dihydrochloride on Nasal Septum Squamous Carcinoma Cells.

Background/Objectives: The aim of this study was to investigate the cytotoxic, genotoxic, apoptotic, and anti-inflammatory effects of the antiseptic agent octenidine dihydrochloride (OCT-D) on the RPMI-2650 cell line derived from human nasal mucosa in vitro. Methods: RPMI-2650 cells and Human Umbilical Cord Endothelial Cells (HUVECs) were treated with various concentrations of OCT-D (0.00625-0.4%) for 12 and 24 h. Cell viability was assessed using the WST-1 assay, while DNA damage was assessed using the comet and micronucleus (MN) assays. Apoptotic activity was determined using Annexin V flow cytometry and fluorescence microscopy. Intracellular reactive oxygen species (ROS) levels were measured, and inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) were measured by Enzyme-Linked Immunosorbent Assay (ELISA). The mRNA expression of genes associated with apoptosis, oxidative stress, and inflammation was analyzed using RT-PCR. Results: OCT-D caused dose- and time-dependent cytotoxicity, and RPMI-2650 cells showed greater resistance compared to HUVECs. While a strong apoptotic response was observed in HUVECs, RPMI-2650 cells exhibited limited apoptosis. OCT-D was found to cause dose-dependent DNA damage and an increase in MN in both cell lines. OCT-D significantly reduced cytokine levels and ROS production in both cell types. RT-PCR results supported its anti-inflammatory and antioxidant effects at the molecular level. Conclusions: In conclusion, this study demonstrated that OCT-D exhibited minimal cytotoxic and apoptotic effects in RPMI-2650 cells, but affected vascular structure by inducing apoptosis in endothelial cells. These findings provide important evidence that OCT-D can be used as a potential adjunctive agent in nasal treatments, and these data need to be supported by preclinical and clinical studies.