Preparation and Evaluation of a Herbal Mouthwash Containing Oak Husk of Quercus brantii and Zataria multiflora

Background: Considering increasing antibiotic resistance and periodontal diseases incidence, the need of a safe, effective, and economical alternative mouthwash seems necessary. Combination of Persian oak husk of Quercus brantii (Jaft) with astringent and antibacterial properties of its tannins and Zataria multiflora leaves with anti-bacterial activity related to its essential oil seems to be more effective. Objectives: The aim of the present study was to prepare and evaluate a herbal mouthwash formulation containing the extract of Oak husk and essential oil of Zataria multiflora. Methods: The essential oil of Zataria multiflora leaves was obtained by hydro-distillation. Oak husk powder of Quercus brantii was extracted by infusion and then the extract was freeze-dried. Determination of tannin amount in the extract was performed by the Folin-Denis method. The essential oil analysis was performed by GC/MS. Formulations were prepared at five different concentrations of tannin (0.1%, 0.2%, 0.5%, 1%, and 2%) with 0.15% v/v of essential oil in the base of polyethylene glycol 400 and propylene glycol. The selected formulations were subjected to screening against Candida albicans, Lactobacillus acidophilus, Staphylococcus aureus, and Streptococcus mutans, using standard protocol of cell viability in comparison to the Persicamouthwash. Stability tests, such as tannin assay and pH, were done on days zero and forty-five after preparation of the formulations. Results and Conclusions: The best formulations with 0.2% and 0.5% of tannin, which were more stable and showed significantly more antibacterial effects than Persica mouthwash may be safe and effective for future clinical studies.