In Vitro Assessment of Eugenol’s Impact on Human Keratinocyte (Hacat) Cell Line

Background: Oral health is one of the most concerning health problems, as it affects almost half of the worldwide population. Eugenol is an excellent natural compound when it comes to prophylactic and curative treatments for several oral problems. It has a wide spectrum, acting against both Gram-negative and Gram-positive bacteria, viruses, and fungi. For this reason, it can be used in treating various dental problems, such as dental caries and periodontitis, and can be used to alleviate pain after surgical extractions. Eugenol has been tested over the years, and it has been proven to induce cytotoxic effects depending on the dosage. Methods: HaCaT cells were used to evaluate eugenol’s safety. Cell confluence, cell morphology assessment, LDH release, and average cell area measurement were analyzed at concentrations of 20, 40, and 80 µg/mL after 72 hours. Results: Eugenol exhibited a mild, dose-dependent antiproliferative effect without inducing cytotoxicity. LDH release remained below 30% even at the highest concentration, and only slight reductions in average cell area and confluence were observed, with no major morphological changes. Conclusion: These findings indicate that eugenol is safe for use on healthy keratinocytes at concentrations up to 80 µg/mL. This study supports future research aimed at optimizing its therapeutic potential while minimizing adverse effects.