Stability and Cytotoxicity Assessments of Hypericum Perforatum Nanoemulsion in Preventing Denture-related Stomatitis

There is a growing interest in natural antimicrobials based on herbs, which can be used to prevent and treat oral and dental infections.

The aim of this study was to evaluate the stability and the cytotoxicity of a Hypericum perforatum nanoemulsion used to prevent denture-related stomatitis.

The ultrasonic method was used to prepare a Hypericum perforatum nanoemulsion. The prepared nanoemulsion was then characterized using conventional methods. The emulsion resistance to centrifugation was studied, and the formulation was kept at room temperature for 2 months, and any phase separation was checked. Besides, the changes in droplet diameter, polydispersity index (PDI), and surface charge were compared at different time intervals. Finally, the cytotoxicity test was conducted to determine the toxicity of the prepared nanoemulsion against human gingival fibroblasts (HGFs).

The prepared nanoemulsion demonstrated proper physicochemical properties with no cytotoxicity against HGFs. The droplet size, PDI, and surface charge of the nanoemulsion showed a slight increase after 30 days (P=0.6). After 60 days, the increase in the droplet size, PDI, and surface charge were significant (P=0.03). However, the droplet size was still preserved below 200 nm, and the PDI was less than 0.7. Nanoemulsion also showed no physical changes or phase separation after centrifugation and two months of keeping at different temperatures.

The prepared nanoemulsion can be used to prevent and treat oral and dental infectious diseases like denture-related stomatitis.